--- _id: '3987' abstract: - lang: eng text: 'We consider scientific data sets that describe density functions over three-dimensional geometric domains. Such data sets are often large and coarsened representations are needed for visualization and analysis. Assuming a tetrahedral mesh representation, we construct such representations with a simplification algorithm that combines three goals: the approximation of the function, the preservation of the mesh topology, and the improvement of the mesh quality. The third goal is achieved with a novel extension of the well-known quadric error metric. We perform a number of computational experiments to understand the effect of mesh quality improvement on the density map approximation. In addition, we study the effect of geometric simplification on the topological features of the function by monitoring its critical points.' author: - first_name: Vijay full_name: Natarajan, Vijay last_name: Natarajan - first_name: Herbert full_name: Herbert Edelsbrunner id: 3FB178DA-F248-11E8-B48F-1D18A9856A87 last_name: Edelsbrunner orcid: 0000-0002-9823-6833 citation: ama: Natarajan V, Edelsbrunner H. Simplification of three-dimensional density maps. IEEE Transactions on Visualization and Computer Graphics. 2004;10(5):587-597. doi:10.1109/TVCG.2004.32 apa: Natarajan, V., & Edelsbrunner, H. (2004). Simplification of three-dimensional density maps. IEEE Transactions on Visualization and Computer Graphics. IEEE. https://doi.org/10.1109/TVCG.2004.32 chicago: Natarajan, Vijay, and Herbert Edelsbrunner. “Simplification of Three-Dimensional Density Maps.” IEEE Transactions on Visualization and Computer Graphics. IEEE, 2004. https://doi.org/10.1109/TVCG.2004.32. ieee: V. Natarajan and H. Edelsbrunner, “Simplification of three-dimensional density maps,” IEEE Transactions on Visualization and Computer Graphics, vol. 10, no. 5. IEEE, pp. 587–597, 2004. ista: Natarajan V, Edelsbrunner H. 2004. Simplification of three-dimensional density maps. IEEE Transactions on Visualization and Computer Graphics. 10(5), 587–597. mla: Natarajan, Vijay, and Herbert Edelsbrunner. “Simplification of Three-Dimensional Density Maps.” IEEE Transactions on Visualization and Computer Graphics, vol. 10, no. 5, IEEE, 2004, pp. 587–97, doi:10.1109/TVCG.2004.32. short: V. Natarajan, H. Edelsbrunner, IEEE Transactions on Visualization and Computer Graphics 10 (2004) 587–597. date_created: 2018-12-11T12:06:17Z date_published: 2004-07-12T00:00:00Z date_updated: 2021-01-12T07:53:40Z day: '12' doi: 10.1109/TVCG.2004.32 extern: 1 intvolume: ' 10' issue: '5' month: '07' page: 587 - 597 publication: IEEE Transactions on Visualization and Computer Graphics publication_status: published publisher: IEEE publist_id: '2142' quality_controlled: 0 status: public title: Simplification of three-dimensional density maps type: journal_article volume: 10 year: '2004' ... --- OA_place: repository OA_type: green _id: '3988' abstract: - lang: eng text: We give an algorithm that locally improves the fit between two proteins modeled as space-filling diagrams. The algorithm defines the fit in purely geometric terms and improves by applying a rigid motion to one of the two proteins. Our implementation of the algorithm takes between three and ten seconds and converges with high likelihood to the correct docked configuration, provided it starts at a position away from the correct one by at most 18 degrees of rotation and at most 3.0Angstrom of translation. The speed and convergence radius make this an attractive algorithm to use in combination with a coarse sampling of the six-dimensional space of rigid motions. acknowledgement: Supported by NSF under grant CCR-00-86013, BGT Postdoc Program from Duke University and NIH under grant R01 GM61822-01. alternative_title: - Lecture Notes in Computer Science article_processing_charge: No author: - first_name: Vicky full_name: Choi, Vicky last_name: Choi - first_name: Pankaj full_name: Agarwal, Pankaj last_name: Agarwal - first_name: Herbert full_name: Edelsbrunner, Herbert id: 3FB178DA-F248-11E8-B48F-1D18A9856A87 last_name: Edelsbrunner orcid: 0000-0002-9823-6833 - first_name: Johannes full_name: Rudolph, Johannes last_name: Rudolph citation: ama: 'Choi V, Agarwal P, Edelsbrunner H, Rudolph J. Local search heuristic for rigid protein docking. In: Proceedings of the 4th International Workshop of Algorithms in Bioinformatics. Vol 3240. Springer Nature; 2004:218-229. doi:10.1007/978-3-540-30219-3_19' apa: 'Choi, V., Agarwal, P., Edelsbrunner, H., & Rudolph, J. (2004). Local search heuristic for rigid protein docking. In Proceedings of the 4th International Workshop of Algorithms in Bioinformatics (Vol. 3240, pp. 218–229). Bergen, Norway: Springer Nature. https://doi.org/10.1007/978-3-540-30219-3_19' chicago: Choi, Vicky, Pankaj Agarwal, Herbert Edelsbrunner, and Johannes Rudolph. “Local Search Heuristic for Rigid Protein Docking.” In Proceedings of the 4th International Workshop of Algorithms in Bioinformatics, 3240:218–29. Springer Nature, 2004. https://doi.org/10.1007/978-3-540-30219-3_19. ieee: V. Choi, P. Agarwal, H. Edelsbrunner, and J. Rudolph, “Local search heuristic for rigid protein docking,” in Proceedings of the 4th International Workshop of Algorithms in Bioinformatics, Bergen, Norway, 2004, vol. 3240, pp. 218–229. ista: 'Choi V, Agarwal P, Edelsbrunner H, Rudolph J. 2004. Local search heuristic for rigid protein docking. Proceedings of the 4th International Workshop of Algorithms in Bioinformatics. WABI: 4th International Workshop on Algorithms in Bioinformatics, Lecture Notes in Computer Science, vol. 3240, 218–229.' mla: Choi, Vicky, et al. “Local Search Heuristic for Rigid Protein Docking.” Proceedings of the 4th International Workshop of Algorithms in Bioinformatics, vol. 3240, Springer Nature, 2004, pp. 218–29, doi:10.1007/978-3-540-30219-3_19. short: V. Choi, P. Agarwal, H. Edelsbrunner, J. Rudolph, in:, Proceedings of the 4th International Workshop of Algorithms in Bioinformatics, Springer Nature, 2004, pp. 218–229. conference: end_date: 2004-09-21 location: Bergen, Norway name: 'WABI: 4th International Workshop on Algorithms in Bioinformatics' start_date: 2004-09-17 date_created: 2018-12-11T12:06:17Z date_published: 2004-10-01T00:00:00Z date_updated: 2026-05-29T12:02:16Z day: '01' doi: 10.1007/978-3-540-30219-3_19 extern: '1' intvolume: ' 3240' language: - iso: eng main_file_link: - open_access: '1' url: https://www.math.unm.edu/~vageli/courses/Ma504/matlab/project/pdf/docking_RMSD.pdf month: '10' oa: 1 oa_version: Preprint page: 218 - 229 publication: Proceedings of the 4th International Workshop of Algorithms in Bioinformatics publication_identifier: eisbn: - '9783540302193' isbn: - '9783540230182' publication_status: published publisher: Springer Nature publist_id: '2136' quality_controlled: '1' scopus_import: '1' status: public title: Local search heuristic for rigid protein docking type: conference user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 3240 year: '2004' ... --- OA_type: closed access _id: '4172' abstract: - lang: eng text: 'During vertebrate gastrulation, a relatively limited number of blastodermal cells undergoes a stereotypical set of cellular movements that leads to formation of the three germ layers: ectoderm, mesoderm and endoderm. Gastrulation, therefore, provides a unique developmental system in which to study cell movements in vivo in a fairly simple cellular context. Recent advances have been made in elucidating the cellular and molecular mechanisms that underlie cell movements during zebrafish gastrulation. These findings can be compared with observations made in other model systems to identify potential general mechanisms of cell migration during development.' article_processing_charge: No article_type: review author: - first_name: Juan full_name: Montero, Juan last_name: Montero - first_name: Carl-Philipp J full_name: Heisenberg, Carl-Philipp J id: 39427864-F248-11E8-B48F-1D18A9856A87 last_name: Heisenberg orcid: 0000-0002-0912-4566 citation: ama: 'Montero J, Heisenberg C-PJ. Gastrulation dynamics: cells move into focus. Trends in Cell Biology. 2004;14(11):620-627. doi:10.1016/j.tcb.2004.09.008' apa: 'Montero, J., & Heisenberg, C.-P. J. (2004). Gastrulation dynamics: cells move into focus. Trends in Cell Biology. Elsevier. https://doi.org/10.1016/j.tcb.2004.09.008' chicago: 'Montero, Juan, and Carl-Philipp J Heisenberg. “Gastrulation Dynamics: Cells Move into Focus.” Trends in Cell Biology. Elsevier, 2004. https://doi.org/10.1016/j.tcb.2004.09.008.' ieee: 'J. Montero and C.-P. J. Heisenberg, “Gastrulation dynamics: cells move into focus,” Trends in Cell Biology, vol. 14, no. 11. Elsevier, pp. 620–627, 2004.' ista: 'Montero J, Heisenberg C-PJ. 2004. Gastrulation dynamics: cells move into focus. Trends in Cell Biology. 14(11), 620–627.' mla: 'Montero, Juan, and Carl-Philipp J. Heisenberg. “Gastrulation Dynamics: Cells Move into Focus.” Trends in Cell Biology, vol. 14, no. 11, Elsevier, 2004, pp. 620–27, doi:10.1016/j.tcb.2004.09.008.' short: J. Montero, C.-P.J. Heisenberg, Trends in Cell Biology 14 (2004) 620–627. date_created: 2018-12-11T12:07:23Z date_published: 2004-11-01T00:00:00Z date_updated: 2026-05-29T11:53:49Z day: '01' doi: 10.1016/j.tcb.2004.09.008 extern: '1' external_id: pmid: - '15519851' intvolume: ' 14' issue: '11' language: - iso: eng month: '11' oa_version: None page: 620 - 627 pmid: 1 publication: Trends in Cell Biology publication_identifier: issn: - 0962-8924 unknown: - 1879-3088 publication_status: published publisher: Elsevier publist_id: '1948' quality_controlled: '1' scopus_import: '1' status: public title: 'Gastrulation dynamics: cells move into focus' type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 14 year: '2004' ... --- OA_type: closed access _id: '4224' abstract: - lang: eng text: Developing cells acquire positional information by reading the graded distribution of morphogens. In Drosophila, the Dpp morphogen forms a long-range concentration gradient by spreading from a restricted source in the developing wing. It has been assumed that Dpp spreads by extracellular diffusion. Under this assumption, the main role of endocytosis in gradient formation is to downregulate receptors at the cell surface. These surface receptors bind to the ligand and thereby interfere with its long-range movement. Recent experiments indicate that Dpp spreading is mediated by Dynamin-dependent endocytosis in the target tissue, suggesting that extracellular diffusion alone cannot account for Dpp dispersal. Here, we perform a theoretical study of a model for morphogen spreading based on extracellular diffusion, which takes into account receptor binding and trafficking. We compare profiles of ligand and surface receptors obtained in this model with experimental data. To this end, we monitored directly the pool of surface receptors and extracellular Dpp with specific antibodies. We conclude that current models considering pure extracellular diffusion cannot explain the observed role of endocytosis during Dpp long-range movement. article_processing_charge: No article_type: original author: - first_name: Karsten full_name: Kruse, Karsten last_name: Kruse - first_name: Periklis full_name: Pantazis, Periklis last_name: Pantazis - first_name: Mark Tobias full_name: Bollenbach, Mark Tobias id: 3E6DB97A-F248-11E8-B48F-1D18A9856A87 last_name: Bollenbach orcid: 0000-0003-4398-476X - first_name: Frank full_name: Julicher, Frank last_name: Julicher - first_name: Marcos full_name: Gonzalez Gaitan, Marcos last_name: Gonzalez Gaitan citation: ama: 'Kruse K, Pantazis P, Bollenbach MT, Julicher F, Gonzalez Gaitan M. Dpp gradient formation by dynamin-dependent endocytosis: receptor trafficking and the diffusion model. Development. 2004;131(19):4843-4856. doi:10.1242/dev.01335' apa: 'Kruse, K., Pantazis, P., Bollenbach, M. T., Julicher, F., & Gonzalez Gaitan, M. (2004). Dpp gradient formation by dynamin-dependent endocytosis: receptor trafficking and the diffusion model. Development. Company of Biologists. https://doi.org/10.1242/dev.01335' chicago: 'Kruse, Karsten, Periklis Pantazis, Mark Tobias Bollenbach, Frank Julicher, and Marcos Gonzalez Gaitan. “Dpp Gradient Formation by Dynamin-Dependent Endocytosis: Receptor Trafficking and the Diffusion Model.” Development. Company of Biologists, 2004. https://doi.org/10.1242/dev.01335.' ieee: 'K. Kruse, P. Pantazis, M. T. Bollenbach, F. Julicher, and M. Gonzalez Gaitan, “Dpp gradient formation by dynamin-dependent endocytosis: receptor trafficking and the diffusion model,” Development, vol. 131, no. 19. Company of Biologists, pp. 4843–4856, 2004.' ista: 'Kruse K, Pantazis P, Bollenbach MT, Julicher F, Gonzalez Gaitan M. 2004. Dpp gradient formation by dynamin-dependent endocytosis: receptor trafficking and the diffusion model. Development. 131(19), 4843–4856.' mla: 'Kruse, Karsten, et al. “Dpp Gradient Formation by Dynamin-Dependent Endocytosis: Receptor Trafficking and the Diffusion Model.” Development, vol. 131, no. 19, Company of Biologists, 2004, pp. 4843–56, doi:10.1242/dev.01335.' short: K. Kruse, P. Pantazis, M.T. Bollenbach, F. Julicher, M. Gonzalez Gaitan, Development 131 (2004) 4843–4856. date_created: 2018-12-11T12:07:41Z date_published: 2004-10-01T00:00:00Z date_updated: 2026-05-29T11:09:03Z day: '01' doi: 10.1242/dev.01335 extern: '1' external_id: pmid: - '15358671' intvolume: ' 131' issue: '19' keyword: - Drosophila - Morphogens - TGFβ language: - iso: eng month: '10' oa_version: None page: 4843 - 4856 pmid: 1 publication: Development publication_status: published publisher: Company of Biologists publist_id: '1893' quality_controlled: '1' scopus_import: '1' status: public title: 'Dpp gradient formation by dynamin-dependent endocytosis: receptor trafficking and the diffusion model' type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 131 year: '2004' ... --- _id: '4236' article_processing_charge: No author: - first_name: Harold full_name: de Vladar, Harold id: 2A181218-F248-11E8-B48F-1D18A9856A87 last_name: de Vladar orcid: 0000-0002-5985-7653 citation: ama: de Vladar H. Métodos no lineales y sus aplicaciones en dinámicas aleatorias de poblaciones celulares. 2004. apa: de Vladar, H. (2004). Métodos no lineales y sus aplicaciones en dinámicas aleatorias de poblaciones celulares. Centro de estudios avazados, IVIC. chicago: Vladar, Harold de. “Métodos No Lineales y Sus Aplicaciones En Dinámicas Aleatorias de Poblaciones Celulares.” Centro de estudios avazados, IVIC, 2004. ieee: H. de Vladar, “Métodos no lineales y sus aplicaciones en dinámicas aleatorias de poblaciones celulares,” Centro de estudios avazados, IVIC, 2004. ista: de Vladar H. 2004. Métodos no lineales y sus aplicaciones en dinámicas aleatorias de poblaciones celulares. Centro de estudios avazados, IVIC. mla: de Vladar, Harold. Métodos No Lineales y Sus Aplicaciones En Dinámicas Aleatorias de Poblaciones Celulares. Centro de estudios avazados, IVIC, 2004. short: H. de Vladar, Métodos No Lineales y Sus Aplicaciones En Dinámicas Aleatorias de Poblaciones Celulares, Centro de estudios avazados, IVIC, 2004. date_created: 2018-12-11T12:07:46Z date_published: 2004-01-01T00:00:00Z date_updated: 2025-07-01T12:02:56Z day: '01' extern: '1' language: - iso: eng month: '01' oa_version: None publication_status: published publisher: Centro de estudios avazados, IVIC publist_id: '1877' status: public title: Métodos no lineales y sus aplicaciones en dinámicas aleatorias de poblaciones celulares type: dissertation user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2004' ... --- _id: '4238' abstract: - lang: eng text: The dynamical basis of tumoral growth has been controversial. Many models have been proposed to explain cancer development. The descriptions employ exponential, potential, logistic or Gompertzian growth laws. Some of these models are concerned with the interaction between cancer and the immunological, system. Among other properties, these models are concerned with the microscopic behavior of tumors and the emergence of cancer. We propose a modification of a previous model by Stepanova, which describes the specific immunological response against cancer. The modification consists of the substitution of a Gompertian law for the exponential rate used for tumoral growth. This modification is motivated by the numerous works confirming that Gompertz's equation correctly describes solid tumor growth. The modified model predicts that near zero, tumors always tend to grow. Immunological contraposition never suffices to induce a complete regression of the tumor. Instead, a stable microscopic equilibrium between cancer and immunological activity can be attained. In other words, our model predicts that the theory of immune surveillance is plausible. A macroscopic equilibrium in which the system develops cancer is also possible. In this case, immunological activity is depleted. This is consistent with the phenomena of cancer tolerance. Both equilibrium points can coexist or can exist without the other. In all cases the fixed point at zero tumor size is unstable. Since immunity cannot induce a complete tumor regression, a therapy is required. We include constant-dose therapies and show that they are insufficient. Final levels of immunocompetent cells and tumoral cells are finite, thus post-treatment regrowth of the tumor is certain. We also evaluate late-intensification therapies which are successful. They induce an asymptotic regression to zero tumor size. Immune response is also suppressed by the therapy, and thus plays a negligible role in the remission. We conclude that treatment evaluation should be successful without taking into account immunological effects. (C) 2003 Elsevier Ltd. All rights reserved. article_processing_charge: No article_type: original author: - first_name: Harold full_name: de Vladar, Harold id: 2A181218-F248-11E8-B48F-1D18A9856A87 last_name: de Vladar orcid: 0000-0002-5985-7653 - first_name: J. full_name: González, J. last_name: González citation: ama: de Vladar H, González J. Dynamic response of cancer under the influence of immunological activity and therapy. Journal of Theoretical Biology. 2004;227(3):335-348. doi:10.1016/j.jtbi.2003.11.012 apa: de Vladar, H., & González, J. (2004). Dynamic response of cancer under the influence of immunological activity and therapy. Journal of Theoretical Biology. Elsevier. https://doi.org/10.1016/j.jtbi.2003.11.012 chicago: Vladar, Harold de, and J. González. “Dynamic Response of Cancer under the Influence of Immunological Activity and Therapy.” Journal of Theoretical Biology. Elsevier, 2004. https://doi.org/10.1016/j.jtbi.2003.11.012. ieee: H. de Vladar and J. González, “Dynamic response of cancer under the influence of immunological activity and therapy,” Journal of Theoretical Biology, vol. 227, no. 3. Elsevier, pp. 335–348, 2004. ista: de Vladar H, González J. 2004. Dynamic response of cancer under the influence of immunological activity and therapy. Journal of Theoretical Biology. 227(3), 335–348. mla: de Vladar, Harold, and J. González. “Dynamic Response of Cancer under the Influence of Immunological Activity and Therapy.” Journal of Theoretical Biology, vol. 227, no. 3, Elsevier, 2004, pp. 335–48, doi:10.1016/j.jtbi.2003.11.012. short: H. de Vladar, J. González, Journal of Theoretical Biology 227 (2004) 335–348. date_created: 2018-12-11T12:07:46Z date_published: 2004-04-07T00:00:00Z date_updated: 2025-07-01T12:00:54Z day: '07' doi: 10.1016/j.jtbi.2003.11.012 extern: '1' intvolume: ' 227' issue: '3' language: - iso: eng month: '04' oa_version: None page: 335 - 348 publication: Journal of Theoretical Biology publication_status: published publisher: Elsevier publist_id: '1876' quality_controlled: '1' related_material: record: - id: '4235' relation: later_version status: public scopus_import: '1' status: public title: Dynamic response of cancer under the influence of immunological activity and therapy type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 227 year: '2004' ... --- _id: '4239' abstract: - lang: eng text: The first living organisms were not necessarily the result of the assembly of fully structured biochemical mechanisms involving macromolecules, but at least some life-related processes, as we know them today, probably appeared alongside the structural integration and early evolution of these proto-organisms. Along these ideas, we consider that spatial compartmentalization and protein functionality are tightly related in their origin. A possible scenario of this relationship is the early polymerization of amino acids (AA) embedded in amphiphilic membranes. The resulting membrane-embedded proto-proteins could have played an important role modulating the transport of elements or ions between the internal compartment and the environment. This scenario is congruent with selectivity arguments of AA (Hitz & DeLuisi, 2000) (i.e., 20 out of nearly 70 originally available (Croning & Chang, 1993; Engel & Nagy, 1982)) and their homochirality (Hitz et al., 2001). Other mechanisms of peptide bond formation, such as alumina-catalyzed reactions (Bujdak & Rode, 2002), polymerization on clay surfaces (Bujdak & Rode, 1996) and polymerization mediated by thioesters (De Duve, 1996), can also lead to this scenario. alternative_title: - Cellular Origin, Life in Extreme Habitats and Astrobiology article_processing_charge: No author: - first_name: Harold full_name: Vladar, Harold id: 2A181218-F248-11E8-B48F-1D18A9856A87 last_name: Vladar orcid: 0000-0002-5985-7653 - first_name: Roberto full_name: Cipriani, Roberto last_name: Cipriani - first_name: Benjamin full_name: Scharifker, Benjamin last_name: Scharifker - first_name: Jose full_name: Bubis, Jose last_name: Bubis citation: ama: 'de Vladar H, Cipriani R, Scharifker B, Bubis J. A Mechanism for the Prebiotic Emergence of Proteins. In: Seckbach J, Chela Flores J, Owen T, Raulin F, eds. Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds. Vol 7. COLE. Springer; 2004:83-87. doi:10.1007/978-94-007-1003-0_12' apa: de Vladar, H., Cipriani, R., Scharifker, B., & Bubis, J. (2004). A Mechanism for the Prebiotic Emergence of Proteins. In J. Seckbach, J. Chela Flores, T. Owen, & F. Raulin (Eds.), Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds (Vol. 7, pp. 83–87). Springer. https://doi.org/10.1007/978-94-007-1003-0_12 chicago: Vladar, Harold de, Roberto Cipriani, Benjamin Scharifker, and Jose Bubis. “A Mechanism for the Prebiotic Emergence of Proteins.” In Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds, edited by J. Seckbach, J. Chela Flores, T. Owen, and F. Raulin, 7:83–87. COLE. Springer, 2004. https://doi.org/10.1007/978-94-007-1003-0_12. ieee: H. de Vladar, R. Cipriani, B. Scharifker, and J. Bubis, “A Mechanism for the Prebiotic Emergence of Proteins,” in Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds, vol. 7, J. Seckbach, J. Chela Flores, T. Owen, and F. Raulin, Eds. Springer, 2004, pp. 83–87. ista: 'de Vladar H, Cipriani R, Scharifker B, Bubis J. 2004.A Mechanism for the Prebiotic Emergence of Proteins. In: Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds. Cellular Origin, Life in Extreme Habitats and Astrobiology, vol. 7, 83–87.' mla: de Vladar, Harold, et al. “A Mechanism for the Prebiotic Emergence of Proteins.” Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds, edited by J. Seckbach et al., vol. 7, Springer, 2004, pp. 83–87, doi:10.1007/978-94-007-1003-0_12. short: H. de Vladar, R. Cipriani, B. Scharifker, J. Bubis, in:, J. Seckbach, J. Chela Flores, T. Owen, F. Raulin (Eds.), Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds, Springer, 2004, pp. 83–87. date_created: 2018-12-11T12:07:47Z date_published: 2004-01-01T00:00:00Z date_updated: 2025-06-26T09:14:02Z day: '01' doi: 10.1007/978-94-007-1003-0_12 editor: - first_name: J. full_name: Seckbach, J. last_name: Seckbach - first_name: J. full_name: Chela Flores, J. last_name: Chela Flores - first_name: T. full_name: Owen, T. last_name: Owen - first_name: F. full_name: Raulin, F. last_name: Raulin extern: '1' intvolume: ' 7' language: - iso: eng month: '01' oa_version: None page: 83 - 87 publication: Life in the Universe. From the Miller Experiment to the Search for Life on Other Worlds publication_status: published publisher: Springer publist_id: '1875' quality_controlled: '1' scopus_import: '1' series_title: COLE status: public title: A Mechanism for the Prebiotic Emergence of Proteins type: book_chapter user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 7 year: '2004' ... --- OA_place: repository OA_type: green _id: '4253' abstract: - lang: eng text: We consider a single genetic locus which carries two alleles, labelled P and Q. This locus experiences selection and mutation. It is linked to a second neutral locus with recombination rate r. If r = 0, this reduces to the study of a single selected locus. Assuming a Moran model for the population dynamics, we pass to a diffusion approximation and, assuming that the allele frequencies at the selected locus have reached stationarity, establish the joint generating function for the genealogy of a sample from the population and the frequency of the P allele. In essence this is the joint generating function for a coalescent and the random background in which it evolves. We use this to characterize, for the diffusion approximation, the probability of identity in state at the neutral locus of a sample of two individuals (whose type at the selected locus is known) as solutions to a system of ordinary differential equations. The only subtlety is to find the boundary conditions for this system. Finally, numerical examples are presented that illustrate the accuracy and predictions of the diffusion approximation. In particular, a comparison is made between this approach and one in which the frequencies at the selected locus are estimated by their value in the absence of fluctuations and a classical structured coalescent model is used. article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Nicholas H full_name: Barton, Nicholas H id: 4880FE40-F248-11E8-B48F-1D18A9856A87 last_name: Barton orcid: 0000-0002-8548-5240 - first_name: Alison full_name: Etheridge, Alison last_name: Etheridge - first_name: Anja full_name: Sturm, Anja last_name: Sturm citation: ama: Barton NH, Etheridge A, Sturm A. Coalescence in a Random Background. Annals of Applied Probability. 2004;14(2):754-785. doi:10.1214/105051604000000099 apa: Barton, N. H., Etheridge, A., & Sturm, A. (2004). Coalescence in a Random Background. Annals of Applied Probability. Institute of Mathematical Statistics. https://doi.org/10.1214/105051604000000099 chicago: Barton, Nicholas H, Alison Etheridge, and Anja Sturm. “Coalescence in a Random Background.” Annals of Applied Probability. Institute of Mathematical Statistics, 2004. https://doi.org/10.1214/105051604000000099. ieee: N. H. Barton, A. Etheridge, and A. Sturm, “Coalescence in a Random Background,” Annals of Applied Probability, vol. 14, no. 2. Institute of Mathematical Statistics, pp. 754–785, 2004. ista: Barton NH, Etheridge A, Sturm A. 2004. Coalescence in a Random Background. Annals of Applied Probability. 14(2), 754–785. mla: Barton, Nicholas H., et al. “Coalescence in a Random Background.” Annals of Applied Probability, vol. 14, no. 2, Institute of Mathematical Statistics, 2004, pp. 754–85, doi:10.1214/105051604000000099. short: N.H. Barton, A. Etheridge, A. Sturm, Annals of Applied Probability 14 (2004) 754–785. date_created: 2018-12-11T12:07:52Z date_published: 2004-05-01T00:00:00Z date_updated: 2026-05-29T09:59:37Z day: '01' doi: 10.1214/105051604000000099 extern: '1' external_id: arxiv: - '0406174' intvolume: ' 14' issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.48550/arXiv.math/0406174' month: '05' oa: 1 oa_version: Preprint page: 754 - 785 publication: Annals of Applied Probability publication_identifier: eissn: - 2168-8737 issn: - 1050-5164 publication_status: published publisher: Institute of Mathematical Statistics publist_id: '1842' quality_controlled: '1' scopus_import: '1' status: public title: Coalescence in a Random Background type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 14 year: '2004' ... --- _id: '17717' abstract: - lang: eng text: We demonstrate that constraints on cosmological parameters from the distribution of clusters as a function of redshift (dN/dz) are complementary to accurate angular diameter distance (D_A) measurements to clusters, and their combination significantly tightens constraints on the energy density content of the Universe. The number counts can be obtained from X-ray and/or SZ (Sunyaev-Zel'dovich effect) surveys, and the angular diameter distances can be determined from deep observations of the intra-cluster gas using their thermal bremsstrahlung X-ray emission and the SZ effect. We combine constraints from simulated cluster number counts expected from a 12 deg^2 SZ cluster survey and constraints from simulated angular diameter distance measurements based on the X-ray/SZ method assuming a statistical accuracy of 10% in the angular diameter distance determination of 100 clusters with redshifts less than 1.5. We find that Omega_m can be determined within about 25%, Omega_Lambda within 20%, and w within 16%. We show that combined dN/dz + D_A constraints can be used to constrain the different energy densities in the Universe even in the presence of a few percent redshift dependent systematic error in D_A. We also address the question of how best to select clusters of galaxies for accurate diameter distance determinations. We show that the joint dN/dz + D_A constraints on cosmological parameters for a fixed target accuracy in the energy density parameters are optimized by selecting clusters with redshift upper cut--offs in the range 0.5 < z < 1. article_processing_charge: No article_type: original author: - first_name: Sandor M. full_name: Molnar, Sandor M. last_name: Molnar - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Mark full_name: Birkinshaw, Mark last_name: Birkinshaw - first_name: Richard F. full_name: Mushotzky, Richard F. last_name: Mushotzky citation: ama: Molnar SM, Haiman Z, Birkinshaw M, Mushotzky RF. Constraints on the energy content of the universe from a combination of galaxy cluster observables. The Astrophysical Journal. 2004;601(1):22-27. doi:10.1086/380295 apa: Molnar, S. M., Haiman, Z., Birkinshaw, M., & Mushotzky, R. F. (2004). Constraints on the energy content of the universe from a combination of galaxy cluster observables. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/380295 chicago: Molnar, Sandor M., Zoltán Haiman, Mark Birkinshaw, and Richard F. Mushotzky. “Constraints on the Energy Content of the Universe from a Combination of Galaxy Cluster Observables.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/380295. ieee: S. M. Molnar, Z. Haiman, M. Birkinshaw, and R. F. Mushotzky, “Constraints on the energy content of the universe from a combination of galaxy cluster observables,” The Astrophysical Journal, vol. 601, no. 1. American Astronomical Society, pp. 22–27, 2004. ista: Molnar SM, Haiman Z, Birkinshaw M, Mushotzky RF. 2004. Constraints on the energy content of the universe from a combination of galaxy cluster observables. The Astrophysical Journal. 601(1), 22–27. mla: Molnar, Sandor M., et al. “Constraints on the Energy Content of the Universe from a Combination of Galaxy Cluster Observables.” The Astrophysical Journal, vol. 601, no. 1, American Astronomical Society, 2004, pp. 22–27, doi:10.1086/380295. short: S.M. Molnar, Z. Haiman, M. Birkinshaw, R.F. Mushotzky, The Astrophysical Journal 601 (2004) 22–27. date_created: 2024-09-06T09:02:16Z date_published: 2004-01-20T00:00:00Z date_updated: 2024-09-25T13:08:12Z day: '20' doi: 10.1086/380295 extern: '1' intvolume: ' 601' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/380295 month: '01' oa: 1 oa_version: Published Version page: 22-27 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: Constraints on the energy content of the universe from a combination of galaxy cluster observables type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 601 year: '2004' ... --- _id: '17725' abstract: - lang: eng text: A bright quasar residing in a dense and largely neutral intergalactic medium (IGM) at high redshifts (z > 6) will be surrounded by a large cosmological Stromgren sphere. The quasar's spectrum will then show a sharp increase in resonant Lyman line absorption at wavelengths approaching and shorter than that corresponding to the Stromgren sphere's boundary along the line of sight. We show here that simultaneously considering the measured absorption in two or more hydrogen Lyman lines can provide the dynamical range required to detect this feature. We model broad and robust features of the Lyman alpha and Lyman beta regions of the spectrum of the z=6.28 quasar SDSS J1030+0524, using a hydrodynamical simulation. From the steep wavelength-dependence of the inferred absorption opacity, we detect the boundary of the Stromgren sphere at a proper distance of 6.0 +/- 0.2 Mpc away from the source redshift. From the spectrum alone, we also find that beyond this distance, cosmic hydrogen turns nearly neutral, with a neutral fraction of x_HI > 0.2, and that the ionizing luminosity of this quasar is in the range (5.2 +/- 2.5) times 10^{56} photons/sec. The method presented here, when applied to future quasars, can probe the complex topology of overlapping ionized regions, and can be used to study the details of the reionization process. article_processing_charge: No article_type: original author: - first_name: Andrei full_name: Mesinger, Andrei last_name: Mesinger - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman citation: ama: Mesinger A, Haiman Z. Evidence of a cosmological Strömgren surface and of significant neutral hydrogen surrounding the quasar SDSS J1030+0524. The Astrophysical Journal. 2004;611(2):L69-L72. doi:10.1086/423935 apa: Mesinger, A., & Haiman, Z. (2004). Evidence of a cosmological Strömgren surface and of significant neutral hydrogen surrounding the quasar SDSS J1030+0524. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/423935 chicago: Mesinger, Andrei, and Zoltán Haiman. “Evidence of a Cosmological Strömgren Surface and of Significant Neutral Hydrogen Surrounding the Quasar SDSS J1030+0524.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/423935. ieee: A. Mesinger and Z. Haiman, “Evidence of a cosmological Strömgren surface and of significant neutral hydrogen surrounding the quasar SDSS J1030+0524,” The Astrophysical Journal, vol. 611, no. 2. American Astronomical Society, pp. L69–L72, 2004. ista: Mesinger A, Haiman Z. 2004. Evidence of a cosmological Strömgren surface and of significant neutral hydrogen surrounding the quasar SDSS J1030+0524. The Astrophysical Journal. 611(2), L69–L72. mla: Mesinger, Andrei, and Zoltán Haiman. “Evidence of a Cosmological Strömgren Surface and of Significant Neutral Hydrogen Surrounding the Quasar SDSS J1030+0524.” The Astrophysical Journal, vol. 611, no. 2, American Astronomical Society, 2004, pp. L69–72, doi:10.1086/423935. short: A. Mesinger, Z. Haiman, The Astrophysical Journal 611 (2004) L69–L72. date_created: 2024-09-06T09:12:22Z date_published: 2004-07-19T00:00:00Z date_updated: 2024-09-25T14:12:20Z day: '19' doi: 10.1086/423935 extern: '1' intvolume: ' 611' issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/423935 month: '07' oa: 1 oa_version: Published Version page: L69-L72 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: Evidence of a cosmological Strömgren surface and of significant neutral hydrogen surrounding the quasar SDSS J1030+0524 type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 611 year: '2004' ... --- _id: '17726' abstract: - lang: eng text: We present deep unbiased spectroscopy of the Hubble Ultra Deep Field (UDF) carried out using the slitless grism spectroscopy mode of the Advance Camera for Surveys on the Hubble Space Telescope (HST). The GRIsm ACS Program for Extragalactic Science (GRAPES) achieves continuum detection as faint as zAB=27.2 using 40 orbits (9.2×10^4 seconds) on HST. The data were taken at four orientation angles to correct for the overlap of spectra. GRAPES data provide a unique, uninterrupted, low resolution (R=100) spectral coverage for 5500Å<λ<10500Å, and allow us to detect high redshift galaxies at 4The Astrophysical Journal Supplement Series. 2004;154(2):501-508. doi:10.1086/422582' apa: 'Pirzkal, N., Xu, C., Malhotra, S., Rhoads, J. E., Koekemoer, A. M., Moustakas, L. A., … Yan, H. (2004). GRAPES, grism spectroscopy of the hubble ultra deep field: Description and data reduction. The Astrophysical Journal Supplement Series. American Astronomical Society. https://doi.org/10.1086/422582' chicago: 'Pirzkal, N., C. Xu, S. Malhotra, J. E. Rhoads, A. M. Koekemoer, L. A. Moustakas, J. R. Walsh, et al. “GRAPES, Grism Spectroscopy of the Hubble Ultra Deep Field: Description and Data Reduction.” The Astrophysical Journal Supplement Series. American Astronomical Society, 2004. https://doi.org/10.1086/422582.' ieee: 'N. Pirzkal et al., “GRAPES, grism spectroscopy of the hubble ultra deep field: Description and data reduction,” The Astrophysical Journal Supplement Series, vol. 154, no. 2. American Astronomical Society, pp. 501–508, 2004.' ista: 'Pirzkal N, Xu C, Malhotra S, Rhoads JE, Koekemoer AM, Moustakas LA, Walsh JR, Windhorst RA, Daddi E, Cimatti A, Ferguson HC, Gardner JP, Gronwall C, Haiman Z, Kummel M, Panagia N, Pasquali A, Stiavelli M, di Serego Alighieri S, Tsvetanov Z, Vernet J, Yan H. 2004. GRAPES, grism spectroscopy of the hubble ultra deep field: Description and data reduction. The Astrophysical Journal Supplement Series. 154(2), 501–508.' mla: 'Pirzkal, N., et al. “GRAPES, Grism Spectroscopy of the Hubble Ultra Deep Field: Description and Data Reduction.” The Astrophysical Journal Supplement Series, vol. 154, no. 2, American Astronomical Society, 2004, pp. 501–08, doi:10.1086/422582.' short: N. Pirzkal, C. Xu, S. Malhotra, J.E. Rhoads, A.M. Koekemoer, L.A. Moustakas, J.R. Walsh, R.A. Windhorst, E. Daddi, A. Cimatti, H.C. Ferguson, J.P. Gardner, C. Gronwall, Z. Haiman, M. Kummel, N. Panagia, A. Pasquali, M. Stiavelli, S. di Serego Alighieri, Z. Tsvetanov, J. Vernet, H. Yan, The Astrophysical Journal Supplement Series 154 (2004) 501–508. date_created: 2024-09-06T09:13:05Z date_published: 2004-10-01T00:00:00Z date_updated: 2024-09-25T14:30:24Z doi: 10.1086/422582 extern: '1' intvolume: ' 154' issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/422582 month: '10' oa: 1 oa_version: Published Version page: 501-508 publication: The Astrophysical Journal Supplement Series publication_identifier: issn: - 0067-0049 - 1538-4365 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: 'GRAPES, grism spectroscopy of the hubble ultra deep field: Description and data reduction' type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 154 year: '2004' ... --- _id: '17728' abstract: - lang: eng text: The cosmic ultraviolet (UV) ionizing background impacts the formation of dwarf galaxies in the low-redshift universe (z=3) by suppressing gas infall into galactic halos with circular velocities up to v(circ)=75 km/s. Using a one-dimensional, spherically symmetric hydrodynamics code (Thoul & Weinberg 1995), we examine the effect of an ionizing background on low-mass galaxies forming at high redshifts (z>10). We find that the importance of photoionization feedback is greatly reduced, because (1) at high redshift, dwarf-galaxy sized objects can self-shield against the ionizing background, (2) collisional cooling processes at high redshift are more efficient, (3) the amplitude of the ionizing background at high redshift is lower, and (4) the ionizing radiation turns on when the perturbation that will become the dwarf galaxy has already grown to a substantial overdensity. We find that because of these reasons, gas can collect inside halos with circular velocities as low as v(circ)=10 km/s. This result has important implications for the reionization history of the universe. article_processing_charge: No article_type: original author: - first_name: Mark full_name: Dijkstra, Mark last_name: Dijkstra - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Martin J. full_name: Rees, Martin J. last_name: Rees - first_name: David H. full_name: Weinberg, David H. last_name: Weinberg citation: ama: Dijkstra M, Haiman Z, Rees MJ, Weinberg DH. Photoionization feedback in low‐mass galaxies at high redshift. The Astrophysical Journal. 2004;601(2):666-675. doi:10.1086/380603 apa: Dijkstra, M., Haiman, Z., Rees, M. J., & Weinberg, D. H. (2004). Photoionization feedback in low‐mass galaxies at high redshift. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/380603 chicago: Dijkstra, Mark, Zoltán Haiman, Martin J. Rees, and David H. Weinberg. “Photoionization Feedback in Low‐mass Galaxies at High Redshift.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/380603. ieee: M. Dijkstra, Z. Haiman, M. J. Rees, and D. H. Weinberg, “Photoionization feedback in low‐mass galaxies at high redshift,” The Astrophysical Journal, vol. 601, no. 2. American Astronomical Society, pp. 666–675, 2004. ista: Dijkstra M, Haiman Z, Rees MJ, Weinberg DH. 2004. Photoionization feedback in low‐mass galaxies at high redshift. The Astrophysical Journal. 601(2), 666–675. mla: Dijkstra, Mark, et al. “Photoionization Feedback in Low‐mass Galaxies at High Redshift.” The Astrophysical Journal, vol. 601, no. 2, American Astronomical Society, 2004, pp. 666–75, doi:10.1086/380603. short: M. Dijkstra, Z. Haiman, M.J. Rees, D.H. Weinberg, The Astrophysical Journal 601 (2004) 666–675. date_created: 2024-09-06T09:14:46Z date_published: 2004-02-01T00:00:00Z date_updated: 2024-09-26T07:26:27Z day: '01' doi: 10.1086/380603 extern: '1' intvolume: ' 601' issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/380603 month: '02' oa: 1 oa_version: Published Version page: 666-675 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: Photoionization feedback in low‐mass galaxies at high redshift type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 601 year: '2004' ... --- _id: '17743' abstract: - lang: eng text: We use a physically motivated semi-analytic model, based on the mass function of dark matter halos, to predict the number of radio-loud quasars as a function of redshift and luminosity. Simple models in which the central BH mass scales with the velocity dispersion of its host halo as M(bh) sigma(halo)^5 have been previously found to be consistent with a number of observations, including the optical and X-ray quasar luminosity functions. We find that similar models, when augmented with an empirical prescription for radio emission, overpredict the number of faint (10 micro-Jy) radio sources by 1-2 orders of magnitude. This translates into a more stringent constraint on the low-mass end of the quasar black hole mass function than is available from the Hubble and Chandra Deep Fields. We interpret this discrepancy as evidence that black holes with masses below 10^7 Msun are either rare or are not as radio-loud as their more massive counterparts. Models that exclude BHs with masses below 10^7 Msun are in agreement with the deepest existing radio observations, but still produce a significant tail of high-redshift objects. In the 1-10GHz bands, at the sensitivity of 10 micro-Jy, we find surface densities of 100, 10, and 0.3 deg^-2 for sources located at z>6, 10, and 15, respectively. The discovery of these sources with instruments such as the Allen Telescope Array (ATA), Extended Very Large Array (EVLA), and the Square Kilometer Array (SKA) would open a new window for the study of supermassive BHs at high redshift. We also find surface densities of 0.1 deg^-2 at z > 6 for mJy sources that can be used to study 21 cm absorption from the epoch of reionization. We suggest that, although not yet optically identified, the FIRST survey may have already detected 10^3-10^4 such sources. article_processing_charge: No article_type: original author: - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Eliot full_name: Quataert, Eliot last_name: Quataert - first_name: Geoffrey C. full_name: Bower, Geoffrey C. last_name: Bower citation: ama: 'Haiman Z, Quataert E, Bower GC. Modeling the counts of faint radio‐loud quasars: Constraints on the supermassive black hole population and predictions for high redshift. The Astrophysical Journal. 2004;612(2):698-705. doi:10.1086/422834' apa: 'Haiman, Z., Quataert, E., & Bower, G. C. (2004). Modeling the counts of faint radio‐loud quasars: Constraints on the supermassive black hole population and predictions for high redshift. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/422834' chicago: 'Haiman, Zoltán, Eliot Quataert, and Geoffrey C. Bower. “Modeling the Counts of Faint Radio‐loud Quasars: Constraints on the Supermassive Black Hole Population and Predictions for High Redshift.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/422834.' ieee: 'Z. Haiman, E. Quataert, and G. C. Bower, “Modeling the counts of faint radio‐loud quasars: Constraints on the supermassive black hole population and predictions for high redshift,” The Astrophysical Journal, vol. 612, no. 2. American Astronomical Society, pp. 698–705, 2004.' ista: 'Haiman Z, Quataert E, Bower GC. 2004. Modeling the counts of faint radio‐loud quasars: Constraints on the supermassive black hole population and predictions for high redshift. The Astrophysical Journal. 612(2), 698–705.' mla: 'Haiman, Zoltán, et al. “Modeling the Counts of Faint Radio‐loud Quasars: Constraints on the Supermassive Black Hole Population and Predictions for High Redshift.” The Astrophysical Journal, vol. 612, no. 2, American Astronomical Society, 2004, pp. 698–705, doi:10.1086/422834.' short: Z. Haiman, E. Quataert, G.C. Bower, The Astrophysical Journal 612 (2004) 698–705. date_created: 2024-09-06T09:27:01Z date_published: 2004-09-10T00:00:00Z date_updated: 2024-09-26T14:20:17Z day: '10' doi: 10.1086/422834 extern: '1' intvolume: ' 612' issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/422834 month: '09' oa: 1 oa_version: Published Version page: 698-705 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: 'Modeling the counts of faint radio‐loud quasars: Constraints on the supermassive black hole population and predictions for high redshift' type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 612 year: '2004' ... --- _id: '17745' abstract: - lang: eng text: We quantify and discuss the footprints of neutral hydrogen in the intergalactic medium (IGM) on the spectra of high-redshift (z ~ 6) sources, using mock spectra generated from hydrodynamical simulations of the IGM. We show that it should be possible to extract relevant parameters, including the mean neutral fraction in the IGM and the radius of the local cosmological Strömgren region, from the flux distribution in the observed spectra of distant sources. We focus on quasars, but a similar analysis is applicable to galaxies and gamma-ray burst (GRB) afterglows. We explicitly include uncertainties in the spectral shape of the assumed source template near the Lyα line. Our results suggest that a mean neutral hydrogen fraction, xH, of unity can be statistically distinguished from xH ≈ 10^-2 by combining the spectra of tens of bright (M ≈ -27) quasars. Alternatively, the same distinction can be achieved using the spectra of several hundred sources that are ~100 times fainter. Furthermore, if the radius of the Strömgren sphere can be independently constrained to within ~10%, this distinction can be achieved using a single source. The information derived from such spectra will help in settling the current debate as to what extent the universe was reionized at redshifts near z ~ 6. article_processing_charge: No article_type: original author: - first_name: Andrei full_name: Mesinger, Andrei last_name: Mesinger - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Renyue full_name: Cen, Renyue last_name: Cen citation: ama: Mesinger A, Haiman Z, Cen R. Probing the reionization history using the spectra of high‐redshift sources. The Astrophysical Journal. 2004;613(1):23-35. doi:10.1086/422898 apa: Mesinger, A., Haiman, Z., & Cen, R. (2004). Probing the reionization history using the spectra of high‐redshift sources. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/422898 chicago: Mesinger, Andrei, Zoltán Haiman, and Renyue Cen. “Probing the Reionization History Using the Spectra of High‐redshift Sources.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/422898. ieee: A. Mesinger, Z. Haiman, and R. Cen, “Probing the reionization history using the spectra of high‐redshift sources,” The Astrophysical Journal, vol. 613, no. 1. American Astronomical Society, pp. 23–35, 2004. ista: Mesinger A, Haiman Z, Cen R. 2004. Probing the reionization history using the spectra of high‐redshift sources. The Astrophysical Journal. 613(1), 23–35. mla: Mesinger, Andrei, et al. “Probing the Reionization History Using the Spectra of High‐redshift Sources.” The Astrophysical Journal, vol. 613, no. 1, American Astronomical Society, 2004, pp. 23–35, doi:10.1086/422898. short: A. Mesinger, Z. Haiman, R. Cen, The Astrophysical Journal 613 (2004) 23–35. date_created: 2024-09-06T09:34:05Z date_published: 2004-09-20T00:00:00Z date_updated: 2024-09-26T14:26:47Z day: '20' doi: 10.1086/422898 extern: '1' intvolume: ' 613' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/422898 month: '09' oa: 1 oa_version: Published Version page: 23-35 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: Probing the reionization history using the spectra of high‐redshift sources type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 613 year: '2004' ... --- _id: '17747' abstract: - lang: eng text: Dark Energy dominates the mass-energy content of the universe (about 73%) but we do not understand it. Most of the remainder of the Universe consists of Dark Matter (23%), made of an unknown particle. The problem of the origin of Dark Energy has become the biggest problem in astrophysics and one of the biggest problems in all of science. The major extant X-ray observatories, the Chandra X-ray Observatory and XMM-Newton, do not have the ability to perform large-area surveys of the sky. But Dark Energy is smoothly distributed throughout the universe and the whole universe is needed to study it. There are two basic methods to explore the properties of Dark Energy, viz. geometrical tests (supernovae) and studies of the way in which Dark Energy has influenced the large scale structure of the universe and its evolution. DUO will use the latter method, employing the copious X-ray emission from clusters of galaxies. Clusters of galaxies offer an ideal probe of cosmology because they are the best tracers of Dark Matter and their distribution on very large scales is dominated by the Dark Energy. In order to take the next step in understanding Dark Energy, viz. the measurement of the 'equation of state' parameter 'w', an X-ray telescope following the design of ABRIXAS will be accommodated into a Small Explorer mission in lowearth orbit. The telescope will perform a scan of 6,000 sq. degs. in the area of sky covered by the Sloan Digital Sky Survey (North), together with a deeper, smaller survey in the Southern hemisphere. DUO will detect 10.000 clusters of galaxies, measure the number density of clusters as a function of cosmic time, and the power spectrum of density fluctuations out to a redshift exceeding one. When combined with the spectrum of density fluctuations in the Cosmic Microwave Background from a redshift of 1100, this will provide a powerful lever arm for the crucial measurement of cosmological parameters. article_processing_charge: No author: - first_name: Richard full_name: Griffiths, Richard last_name: Griffiths - first_name: Robert full_name: Petre, Robert last_name: Petre - first_name: Guenther full_name: Hasinger, Guenther last_name: Hasinger - first_name: Peter full_name: Predehl, Peter last_name: Predehl - first_name: Nicholas E. full_name: White, Nicholas E. last_name: White - first_name: Bernd full_name: Aschenbach, Bernd last_name: Aschenbach - first_name: Xavier full_name: Barcons, Xavier last_name: Barcons - first_name: Hans full_name: Bohringer, Hans last_name: Bohringer - first_name: Ulrich G. full_name: Briel, Ulrich G. last_name: Briel - first_name: Lynn full_name: Cominsky, Lynn last_name: Cominsky - first_name: Michael F. full_name: Corcoran, Michael F. last_name: Corcoran - first_name: Udo full_name: Dinger, Udo last_name: Dinger - first_name: Wilhelm J. full_name: Egle, Wilhelm J. last_name: Egle - first_name: Peter full_name: Friedrich, Peter last_name: Friedrich - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Robert full_name: Hartmann, Robert last_name: Hartmann - first_name: J. Patrick full_name: Henry, J. Patrick last_name: Henry - first_name: Horst full_name: Hippmann, Horst last_name: Hippmann - first_name: Jim full_name: Ingersoll, Jim last_name: Ingersoll - first_name: Keith full_name: Jahoda, Keith last_name: Jahoda - first_name: Del T. full_name: Jenstrom, Del T. last_name: Jenstrom - first_name: Steven full_name: Jordan, Steven last_name: Jordan - first_name: Eckhard full_name: Kendziorra, Eckhard last_name: Kendziorra - first_name: "G\x92nther" full_name: "Kettenring, G\x92nther" last_name: Kettenring - first_name: Walter full_name: Kink, Walter last_name: Kink - first_name: Norbert full_name: Meidinger, Norbert last_name: Meidinger - first_name: Takamitsu full_name: Miyaji, Takamitsu last_name: Miyaji - first_name: Joseph full_name: Mohr, Joseph last_name: Mohr - first_name: Siegfried full_name: Mueller, Siegfried last_name: Mueller - first_name: Richard F. full_name: Mushotzky, Richard F. last_name: Mushotzky - first_name: Elmar full_name: Pfeffermann, Elmar last_name: Pfeffermann - first_name: Peter full_name: Schuecker, Peter last_name: Schuecker - first_name: Axel full_name: Schwope, Axel last_name: Schwope - first_name: Mark full_name: Shannon, Mark last_name: Shannon - first_name: Lothar full_name: Strueder, Lothar last_name: Strueder - first_name: Steven J. full_name: Varlese, Steven J. last_name: Varlese citation: ama: 'Griffiths R, Petre R, Hasinger G, et al. DUO: The dark universe observatory. In: Hasinger G, Turner MJL, eds. SPIE Astronomical Telescopes + Instrumentation. Vol 5488. SPIE; 2004. doi:10.1117/12.552171' apa: 'Griffiths, R., Petre, R., Hasinger, G., Predehl, P., White, N. E., Aschenbach, B., … Varlese, S. J. (2004). DUO: The dark universe observatory. In G. Hasinger & M. J. L. Turner (Eds.), SPIE Astronomical Telescopes + Instrumentation (Vol. 5488). Glasgow, United Kingdom: SPIE. https://doi.org/10.1117/12.552171' chicago: 'Griffiths, Richard, Robert Petre, Guenther Hasinger, Peter Predehl, Nicholas E. White, Bernd Aschenbach, Xavier Barcons, et al. “DUO: The Dark Universe Observatory.” In SPIE Astronomical Telescopes + Instrumentation, edited by Guenther Hasinger and Martin J. L. Turner, Vol. 5488. SPIE, 2004. https://doi.org/10.1117/12.552171.' ieee: 'R. Griffiths et al., “DUO: The dark universe observatory,” in SPIE Astronomical Telescopes + Instrumentation, Glasgow, United Kingdom, 2004, vol. 5488.' ista: 'Griffiths R, Petre R, Hasinger G, Predehl P, White NE, Aschenbach B, Barcons X, Bohringer H, Briel UG, Cominsky L, Corcoran MF, Dinger U, Egle WJ, Friedrich P, Haiman Z, Hartmann R, Henry JP, Hippmann H, Ingersoll J, Jahoda K, Jenstrom DT, Jordan S, Kendziorra E, Kettenring G, Kink W, Meidinger N, Miyaji T, Mohr J, Mueller S, Mushotzky RF, Pfeffermann E, Schuecker P, Schwope A, Shannon M, Strueder L, Varlese SJ. 2004. DUO: The dark universe observatory. SPIE Astronomical Telescopes + Instrumentation. UV and Gamma-Ray Space Telescope Systems vol. 5488.' mla: 'Griffiths, Richard, et al. “DUO: The Dark Universe Observatory.” SPIE Astronomical Telescopes + Instrumentation, edited by Guenther Hasinger and Martin J. L. Turner, vol. 5488, SPIE, 2004, doi:10.1117/12.552171.' short: R. Griffiths, R. Petre, G. Hasinger, P. Predehl, N.E. White, B. Aschenbach, X. Barcons, H. Bohringer, U.G. Briel, L. Cominsky, M.F. Corcoran, U. Dinger, W.J. Egle, P. Friedrich, Z. Haiman, R. Hartmann, J.P. Henry, H. Hippmann, J. Ingersoll, K. Jahoda, D.T. Jenstrom, S. Jordan, E. Kendziorra, G. Kettenring, W. Kink, N. Meidinger, T. Miyaji, J. Mohr, S. Mueller, R.F. Mushotzky, E. Pfeffermann, P. Schuecker, A. Schwope, M. Shannon, L. Strueder, S.J. Varlese, in:, G. Hasinger, M.J.L. Turner (Eds.), SPIE Astronomical Telescopes + Instrumentation, SPIE, 2004. conference: end_date: 2004-06-25 location: Glasgow, United Kingdom name: UV and Gamma-Ray Space Telescope Systems start_date: 2004-06-21 date_created: 2024-09-06T09:35:28Z date_published: 2004-10-11T00:00:00Z date_updated: 2024-09-30T07:13:16Z day: '11' doi: 10.1117/12.552171 editor: - first_name: Guenther full_name: Hasinger, Guenther last_name: Hasinger - first_name: Martin J. L. full_name: Turner, Martin J. L. last_name: Turner extern: '1' intvolume: ' 5488' language: - iso: eng main_file_link: - url: https://doi.org/10.1117/12.552171 month: '10' oa_version: None publication: SPIE Astronomical Telescopes + Instrumentation publication_identifier: issn: - 0277-786X publication_status: published publisher: SPIE quality_controlled: '1' scopus_import: '1' status: public title: 'DUO: The dark universe observatory' type: conference user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 5488 year: '2004' ... --- _id: '17758' abstract: - lang: eng text: Krstic has carried out the first quantum mechanical calculations near threshold for the charge transfer (CT) process H^+ + H_2(X ^1Sigma_g^+, nu=0, J=0) --> H(1s) + H_2^+. These results are relevant for models of primordial galaxy and first star formation that require reliable atomic and molecular data for obtaining the early universe hydrogen chemistry. Using the results of Krstic, we calculate the relevant CT rate coefficient for temperatures between 100 and 30,000 K. We also present a simple fit which can be readily implemented into early universe chemical models. Additionally, we explore how the range of previously published data for this reaction translates into uncertainties in the predicted gas temperature and H_2 relative abundance in a collapsing primordial gas cloud. Our new data significantly reduce these cosmological uncertainties that are due to the uncertainties in the previously published CT rate coefficients. article_processing_charge: No article_type: original author: - first_name: Daniel Wolf full_name: Savin, Daniel Wolf last_name: Savin - first_name: Predrag S. full_name: Krsti, Predrag S. last_name: Krsti - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Phillip C. full_name: Stancil, Phillip C. last_name: Stancil citation: ama: Savin DW, Krsti PS, Haiman Z, Stancil PC. Rate Coefficient for H+ + H2(X1Σg+, ν = 0, J = 0) → H(1s) + H2+ Charge Transfer and Some Cosmological Implications. The Astrophysical Journal. 2004;606(2):L167-L170. doi:10.1086/421108 apa: Savin, D. W., Krsti, P. S., Haiman, Z., & Stancil, P. C. (2004). Rate Coefficient for H+ + H2(X1Σg+, ν = 0, J = 0) → H(1s) + H2+ Charge Transfer and Some Cosmological Implications. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/421108 chicago: Savin, Daniel Wolf, Predrag S. Krsti, Zoltán Haiman, and Phillip C. Stancil. “Rate Coefficient for H+ + H2(X1Σg+, ν = 0, J = 0) → H(1s) + H2+ Charge Transfer and Some Cosmological Implications.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/421108. ieee: D. W. Savin, P. S. Krsti, Z. Haiman, and P. C. Stancil, “Rate Coefficient for H+ + H2(X1Σg+, ν = 0, J = 0) → H(1s) + H2+ Charge Transfer and Some Cosmological Implications,” The Astrophysical Journal, vol. 606, no. 2. American Astronomical Society, pp. L167–L170, 2004. ista: Savin DW, Krsti PS, Haiman Z, Stancil PC. 2004. Rate Coefficient for H+ + H2(X1Σg+, ν = 0, J = 0) → H(1s) + H2+ Charge Transfer and Some Cosmological Implications. The Astrophysical Journal. 606(2), L167–L170. mla: Savin, Daniel Wolf, et al. “Rate Coefficient for H+ + H2(X1Σg+, ν = 0, J = 0) → H(1s) + H2+ Charge Transfer and Some Cosmological Implications.” The Astrophysical Journal, vol. 606, no. 2, American Astronomical Society, 2004, pp. L167–70, doi:10.1086/421108. short: D.W. Savin, P.S. Krsti, Z. Haiman, P.C. Stancil, The Astrophysical Journal 606 (2004) L167–L170. date_created: 2024-09-06T09:45:29Z date_published: 2004-05-10T00:00:00Z date_updated: 2024-09-26T14:12:52Z day: '10' doi: 10.1086/421108 extern: '1' intvolume: ' 606' issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/421108 month: '05' oa: 1 oa_version: Published Version page: L167-L170 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' related_material: link: - relation: erratum url: https://doi.org/10.1086/421873 scopus_import: '1' status: public title: Rate Coefficient for H+ + H2(X1Σg+, ν = 0, J = 0) → H(1s) + H2+ Charge Transfer and Some Cosmological Implications type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 606 year: '2004' ... --- _id: '17763' abstract: - lang: eng text: Recent studies have suggested that during their coalescence, binary supermassive black holes (SMBHs) experience typical gravitational recoil velocities that may be as large as ≳100 km s^-1. These velocities exceed the escape velocity vesc from typical dark matter (DM) halos at high redshift (z ≳ 6), and therefore put constraints on scenarios in which early SMBHs grow at the centers of DM halos. Here we quantify these constraints for the most distant known SMBH, with an inferred mass in excess of 10^9 M☉, powering the bright quasar SDSS J1148+5251 discovered in the Sloan Digital Sky Survey at z = 6.43. We assume that this SMBH grew via a combination of accretion and mergers between preexisting seed BHs in individual progenitor halos, and that mergers between progenitors with vesc < vkick disrupt the BH growth process. Our results suggest that under these assumptions, the z ≈ 6 SMBHs had a phase during which they gained mass vary rapidly. In particular, typical z ≈ 3 quasars with luminosities similar to that of SDSS J1148+5251 have recently been inferred to have an average radiative efficiency of epsilon ≈ 20%. The growth rate of the SMBH in SDSS J1148+5251 must have significantly exceeded the Eddington accretion rate with this efficiency. article_processing_charge: No article_type: original author: - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman citation: ama: Haiman Z. Constraints from gravitational recoil on the growth of supermassive black holes at high redshift. The Astrophysical Journal. 2004;613(1):36-40. doi:10.1086/422910 apa: Haiman, Z. (2004). Constraints from gravitational recoil on the growth of supermassive black holes at high redshift. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/422910 chicago: Haiman, Zoltán. “Constraints from Gravitational Recoil on the Growth of Supermassive Black Holes at High Redshift.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/422910. ieee: Z. Haiman, “Constraints from gravitational recoil on the growth of supermassive black holes at high redshift,” The Astrophysical Journal, vol. 613, no. 1. American Astronomical Society, pp. 36–40, 2004. ista: Haiman Z. 2004. Constraints from gravitational recoil on the growth of supermassive black holes at high redshift. The Astrophysical Journal. 613(1), 36–40. mla: Haiman, Zoltán. “Constraints from Gravitational Recoil on the Growth of Supermassive Black Holes at High Redshift.” The Astrophysical Journal, vol. 613, no. 1, American Astronomical Society, 2004, pp. 36–40, doi:10.1086/422910. short: Z. Haiman, The Astrophysical Journal 613 (2004) 36–40. date_created: 2024-09-06T09:50:34Z date_published: 2004-09-20T00:00:00Z date_updated: 2024-09-30T09:12:19Z day: '20' doi: 10.1086/422910 extern: '1' intvolume: ' 613' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/422910 month: '09' oa: 1 oa_version: Published Version page: 36-40 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: Constraints from gravitational recoil on the growth of supermassive black holes at high redshift type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 613 year: '2004' ... --- _id: '17770' abstract: - lang: eng text: "We show that the abundance and redshift distribution (\U0001D451⁢\U0001D441/\U0001D451⁢\U0001D467) of galaxy clusters in future high-yield cluster surveys, combined with the spatial power spectrum [\U0001D443\U0001D450⁡(\U0001D458)] of the same clusters, can place significant constraints on the evolution of the dark energy equation of state, \U0001D464=\U0001D464⁡(\U0001D44E). We evaluate the expected errors on \U0001D464\U0001D44E=−\U0001D451⁢\U0001D464/\U0001D451⁢\U0001D44E and other cosmological parameters using a Fisher matrix approach, and simultaneously including cluster structure evolution parameters in our analysis. We study three different types of forthcoming surveys that will identify clusters based on their x-ray emission (such as DUO, the Dark Universe Observatory), their Sunyaev-Zel'dovich (SZ) decrement (such as SPT, the South Pole Telescope), or their weak-lensing shear (such as LSST, the Large Synoptic Survey Telescope). We find that combining the cluster abundance and power spectrum significantly enhances constraints from either method alone. We show that the weak-lensing survey can deliver a constraint as tight as \U0001D6E5⁢\U0001D464\U0001D44E∼0.1 on the evolution of the dark energy equation of state, and that the x-ray and SZ surveys each yield \U0001D6E5⁢\U0001D464\U0001D44E∼0.4 separately, or \U0001D6E5⁢\U0001D464\U0001D44E∼0.2 when these two surveys are combined. For the x-ray and SZ surveys, constraints on dark energy parameters are improved by a factor of 2 by combining the cluster data with cosmic microwave background anisotropy measurements by Planck, but degrade by a factor of 2 if the survey is required to solve simultaneously for cosmological and cluster structure evolution parameters. The constraint on \U0001D464\U0001D44E from the weak-lensing survey is improved by ∼25% with the addition of Planck data." article_number: '123008' article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Sheng full_name: Wang, Sheng last_name: Wang - first_name: Justin full_name: Khoury, Justin last_name: Khoury - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Morgan full_name: May, Morgan last_name: May citation: ama: Wang S, Khoury J, Haiman Z, May M. Constraining the evolution of dark energy with a combination of galaxy cluster observables. Physical Review D. 2004;70(12). doi:10.1103/physrevd.70.123008 apa: Wang, S., Khoury, J., Haiman, Z., & May, M. (2004). Constraining the evolution of dark energy with a combination of galaxy cluster observables. Physical Review D. American Physical Society. https://doi.org/10.1103/physrevd.70.123008 chicago: Wang, Sheng, Justin Khoury, Zoltán Haiman, and Morgan May. “Constraining the Evolution of Dark Energy with a Combination of Galaxy Cluster Observables.” Physical Review D. American Physical Society, 2004. https://doi.org/10.1103/physrevd.70.123008. ieee: S. Wang, J. Khoury, Z. Haiman, and M. May, “Constraining the evolution of dark energy with a combination of galaxy cluster observables,” Physical Review D, vol. 70, no. 12. American Physical Society, 2004. ista: Wang S, Khoury J, Haiman Z, May M. 2004. Constraining the evolution of dark energy with a combination of galaxy cluster observables. Physical Review D. 70(12), 123008. mla: Wang, Sheng, et al. “Constraining the Evolution of Dark Energy with a Combination of Galaxy Cluster Observables.” Physical Review D, vol. 70, no. 12, 123008, American Physical Society, 2004, doi:10.1103/physrevd.70.123008. short: S. Wang, J. Khoury, Z. Haiman, M. May, Physical Review D 70 (2004). date_created: 2024-09-06T10:00:53Z date_published: 2004-12-17T00:00:00Z date_updated: 2024-09-30T09:50:28Z day: '17' doi: 10.1103/physrevd.70.123008 extern: '1' external_id: arxiv: - '0406331' intvolume: ' 70' issue: '12' language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.48550/arXiv.astro-ph/0406331' month: '12' oa: 1 oa_version: Preprint publication: Physical Review D publication_identifier: issn: - 1550-7998 - 1550-2368 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: Constraining the evolution of dark energy with a combination of galaxy cluster observables type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 70 year: '2004' ... --- _id: '17775' abstract: - lang: eng text: 'We discuss a simple model for the growth of supermassive black holes (BHs) at the center of spheroidal stellar systems. In particular, we assess the hypotheses that (1) star formation in spheroids and BH fueling are proportional to one another, and (2) the BH accretion luminosity stays near the Eddington limit during luminous quasar phases. With the aid of this simple model, we are able to interpret many properties of the QSO luminosity function, including the puzzling steep decline of the characteristic luminosity from redshift z=2 to to z=0: indeed the residual star formation in spheroidal systems is today limited to a small number of bulges, characterized by stellar velocity dispersions a factor of 2-3 smaller those of the elliptical galaxies hosting QSOs at z > 2. A simple consequence of our hypotheses is that the redshift evolution of the QSO emissivity and of the star formation history in spheroids should be roughly parallel. We find this result to be broadly consistent with our knowledge of the evolution of both the global star formation rate, and of the evolution of the QSO emissivity, but we identify interesting discrepancies at both low and high redshifts, to which we offer tentative solutions. Finally, our hypotheses allow us to present a robust method to derive the duty cycle of QSO activity, based on the observed QSO luminosity function, and on the present-day relation between the masses of supermassive BHs and those of their spheroidal host stellar systems. The duty cycle is found to be substantially less than unity, with characteristic values in the range (3-6)x10^(-3), and we compute that the average bolometric radiative efficiency is epsilon=0.07. Finally, we find that the growth in mass of individual black holes at high redshift (z>2) can be dominated by mergers, and is therefore not necessarily limited by accretion.' article_processing_charge: No article_type: original author: - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Luca full_name: Ciotti, Luca last_name: Ciotti - first_name: Jeremiah P. full_name: Ostriker, Jeremiah P. last_name: Ostriker citation: ama: 'Haiman Z, Ciotti L, Ostriker JP. Reasoning from fossils: Learning from the local black hole population about the evolution of quasars. The Astrophysical Journal. 2004;606(2):763-773. doi:10.1086/383022' apa: 'Haiman, Z., Ciotti, L., & Ostriker, J. P. (2004). Reasoning from fossils: Learning from the local black hole population about the evolution of quasars. The Astrophysical Journal. American Astronomical Society. https://doi.org/10.1086/383022' chicago: 'Haiman, Zoltán, Luca Ciotti, and Jeremiah P. Ostriker. “Reasoning from Fossils: Learning from the Local Black Hole Population about the Evolution of Quasars.” The Astrophysical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/383022.' ieee: 'Z. Haiman, L. Ciotti, and J. P. Ostriker, “Reasoning from fossils: Learning from the local black hole population about the evolution of quasars,” The Astrophysical Journal, vol. 606, no. 2. American Astronomical Society, pp. 763–773, 2004.' ista: 'Haiman Z, Ciotti L, Ostriker JP. 2004. Reasoning from fossils: Learning from the local black hole population about the evolution of quasars. The Astrophysical Journal. 606(2), 763–773.' mla: 'Haiman, Zoltán, et al. “Reasoning from Fossils: Learning from the Local Black Hole Population about the Evolution of Quasars.” The Astrophysical Journal, vol. 606, no. 2, American Astronomical Society, 2004, pp. 763–73, doi:10.1086/383022.' short: Z. Haiman, L. Ciotti, J.P. Ostriker, The Astrophysical Journal 606 (2004) 763–773. date_created: 2024-09-06T10:07:44Z date_published: 2004-05-10T00:00:00Z date_updated: 2024-09-30T11:41:03Z day: '10' doi: 10.1086/383022 extern: '1' intvolume: ' 606' issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/383022 month: '05' oa: 1 oa_version: Published Version page: 763-773 publication: The Astrophysical Journal publication_identifier: issn: - 0004-637X - 1538-4357 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: 'Reasoning from fossils: Learning from the local black hole population about the evolution of quasars' type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 606 year: '2004' ... --- _id: '17790' abstract: - lang: eng text: Over the last few years, the Sloan Digital Sky Survey (SDSS) has discovered several hundred quasars with redshift between 4.0 and 6.4. Including the effects of magnification bias, one expects a priori that an appreciable fraction of these objects are gravitationally lensed. We have used the Advanced Camera for Surveys on the Hubble Space Telescope to carry out a snapshot imaging survey of high-redshift SDSS quasars to search for gravitationally split lenses. This paper, the first in a series reporting the results of the survey, describes snapshot observations of four quasars at z = 5.74, 5.82, 5.99, and 6.30, respectively. We find that none of these objects has a lensed companion within 5 mag with a separation larger than 0farcs3; within 2.5 mag we can rule out companions within 0farcs1. Based on the nondetection of strong lensing in these four systems, we constrain the z ∼ 6 luminosity function to a slope of β > -4.63 (3 σ), assuming a break in the quasar luminosity function at M = -24.1. We discuss the implications of this constraint on the ionizing background due to quasars in the early universe. Given that these quasars are not highly magnified, estimates of the masses of their central engines by the Eddington argument must be taken seriously, possibly challenging models of black hole formation. article_processing_charge: No article_type: original author: - first_name: Gordon T. full_name: Richards, Gordon T. last_name: Richards - first_name: Michael A. full_name: Strauss, Michael A. last_name: Strauss - first_name: Bartosz full_name: Pindor, Bartosz last_name: Pindor - first_name: Zoltán full_name: Haiman, Zoltán id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36 last_name: Haiman - first_name: Xiaohui full_name: Fan, Xiaohui last_name: Fan - first_name: Daniel full_name: Eisenstein, Daniel last_name: Eisenstein - first_name: Donald P. full_name: Schneider, Donald P. last_name: Schneider - first_name: Neta A. full_name: Bahcall, Neta A. last_name: Bahcall - first_name: J. full_name: Brinkmann, J. last_name: Brinkmann - first_name: Robert full_name: Brunner, Robert last_name: Brunner citation: ama: Richards GT, Strauss MA, Pindor B, et al. A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z >5.7 sample. The Astronomical Journal. 2004;127(3):1305-1312. doi:10.1086/381906 apa: Richards, G. T., Strauss, M. A., Pindor, B., Haiman, Z., Fan, X., Eisenstein, D., … Brunner, R. (2004). A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z >5.7 sample. The Astronomical Journal. American Astronomical Society. https://doi.org/10.1086/381906 chicago: Richards, Gordon T., Michael A. Strauss, Bartosz Pindor, Zoltán Haiman, Xiaohui Fan, Daniel Eisenstein, Donald P. Schneider, Neta A. Bahcall, J. Brinkmann, and Robert Brunner. “A Snapshot Survey for Gravitational Lenses among z ≥ 4.0 Quasars. I. The z >5.7 Sample.” The Astronomical Journal. American Astronomical Society, 2004. https://doi.org/10.1086/381906. ieee: G. T. Richards et al., “A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z >5.7 sample,” The Astronomical Journal, vol. 127, no. 3. American Astronomical Society, pp. 1305–1312, 2004. ista: Richards GT, Strauss MA, Pindor B, Haiman Z, Fan X, Eisenstein D, Schneider DP, Bahcall NA, Brinkmann J, Brunner R. 2004. A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z >5.7 sample. The Astronomical Journal. 127(3), 1305–1312. mla: Richards, Gordon T., et al. “A Snapshot Survey for Gravitational Lenses among z ≥ 4.0 Quasars. I. The z >5.7 Sample.” The Astronomical Journal, vol. 127, no. 3, American Astronomical Society, 2004, pp. 1305–12, doi:10.1086/381906. short: G.T. Richards, M.A. Strauss, B. Pindor, Z. Haiman, X. Fan, D. Eisenstein, D.P. Schneider, N.A. Bahcall, J. Brinkmann, R. Brunner, The Astronomical Journal 127 (2004) 1305–1312. date_created: 2024-09-06T10:22:30Z date_published: 2004-03-01T00:00:00Z date_updated: 2024-09-30T13:53:57Z day: '01' doi: 10.1086/381906 extern: '1' intvolume: ' 127' issue: '3' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1086/381906 month: '03' oa: 1 oa_version: Published Version page: 1305-1312 publication: The Astronomical Journal publication_identifier: issn: - 0004-6256 - 1538-3881 publication_status: published publisher: American Astronomical Society quality_controlled: '1' scopus_import: '1' status: public title: A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z >5.7 sample type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 127 year: '2004' ...