[{"scopus_import":"1","doi":"10.1086/312177","issue":"1","publication_identifier":{"issn":["0004-637X"]},"_id":"17827","external_id":{"arxiv":["astro-ph/9904340"]},"extern":"1","year":"1999","month":"08","type":"journal_article","abstract":[{"lang":"eng","text":"It is currently unknown whether the universe was reionized by quasars or stars at z ≳ 5. We point out that quasars can be best distinguished from stellar systems by their X-ray emission. Based on a simple hierarchical CDM model, we predict the number counts and X-ray fluxes of quasars at high redshifts. The model is consistent with available data on the luminosity function of high-redshift quasars in the optical and soft X-ray bands. The cumulative contribution of faint, undetected quasars in our model is consistent with the unresolved fraction of the X-ray background. We find that the Chandra X-ray Observatory might detect ~10^2 quasars from redshifts z ≳ 5 per its 17' × 17' field of view at the flux threshold of ~2 × 10^-16 ergs s^-1 cm^-2. The redshifts of these faint point sources could be identified by follow-up infrared observations from the ground or with the Next Generation Space Telescope."}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"X-ray emission from the first quasars","publication":"The Astrophysical Journal","language":[{"iso":"eng"}],"publisher":"American Astronomical Society","date_created":"2024-09-06T12:06:45Z","article_type":"original","oa_version":"Preprint","arxiv":1,"page":"L9-L12","quality_controlled":"1","intvolume":"       521","main_file_link":[{"url":"https://doi.org/10.48550/arXiv.astro-ph/9904340","open_access":"1"}],"date_updated":"2024-11-12T13:00:30Z","OA_place":"repository","oa":1,"author":[{"last_name":"Haiman","orcid":"0000-0003-3633-5403","full_name":"Haiman, Zoltán","first_name":"Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36"},{"last_name":"Loeb","first_name":"Abraham","full_name":"Loeb, Abraham"}],"status":"public","volume":521,"OA_type":"green","article_processing_charge":"No","citation":{"short":"Z. Haiman, A. Loeb, The Astrophysical Journal 521 (1999) L9–L12.","mla":"Haiman, Zoltán, and Abraham Loeb. “X-Ray Emission from the First Quasars.” <i>The Astrophysical Journal</i>, vol. 521, no. 1, American Astronomical Society, 1999, pp. L9–12, doi:<a href=\"https://doi.org/10.1086/312177\">10.1086/312177</a>.","ama":"Haiman Z, Loeb A. X-ray emission from the first quasars. <i>The Astrophysical Journal</i>. 1999;521(1):L9-L12. doi:<a href=\"https://doi.org/10.1086/312177\">10.1086/312177</a>","ista":"Haiman Z, Loeb A. 1999. X-ray emission from the first quasars. The Astrophysical Journal. 521(1), L9–L12.","apa":"Haiman, Z., &#38; Loeb, A. (1999). X-ray emission from the first quasars. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/312177\">https://doi.org/10.1086/312177</a>","chicago":"Haiman, Zoltán, and Abraham Loeb. “X-Ray Emission from the First Quasars.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1999. <a href=\"https://doi.org/10.1086/312177\">https://doi.org/10.1086/312177</a>.","ieee":"Z. Haiman and A. Loeb, “X-ray emission from the first quasars,” <i>The Astrophysical Journal</i>, vol. 521, no. 1. American Astronomical Society, pp. L9–L12, 1999."},"day":"10","publication_status":"published","date_published":"1999-08-10T00:00:00Z"},{"status":"public","oa":1,"author":[{"id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","full_name":"Haiman, Zoltán","first_name":"Zoltán","orcid":"0000-0003-3633-5403","last_name":"Haiman"},{"last_name":"Spaans","full_name":"Spaans, Marco","first_name":"Marco"}],"date_updated":"2024-11-13T07:30:03Z","OA_place":"repository","quality_controlled":"1","main_file_link":[{"url":"https://doi.org/10.48550/arXiv.astro-ph/9809223","open_access":"1"}],"intvolume":"       518","oa_version":"Preprint","arxiv":1,"page":"138-144","article_type":"original","publisher":"American Astronomical Society","date_created":"2024-09-06T12:13:30Z","publication":"The Astrophysical Journal","language":[{"iso":"eng"}],"date_published":"1999-06-10T00:00:00Z","citation":{"apa":"Haiman, Z., &#38; Spaans, M. (1999). Models for dusty Lyα emitters at high redshift. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/307276\">https://doi.org/10.1086/307276</a>","ieee":"Z. Haiman and M. Spaans, “Models for dusty Lyα emitters at high redshift,” <i>The Astrophysical Journal</i>, vol. 518, no. 1. American Astronomical Society, pp. 138–144, 1999.","chicago":"Haiman, Zoltán, and Marco Spaans. “Models for Dusty Lyα Emitters at High Redshift.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1999. <a href=\"https://doi.org/10.1086/307276\">https://doi.org/10.1086/307276</a>.","short":"Z. Haiman, M. Spaans, The Astrophysical Journal 518 (1999) 138–144.","mla":"Haiman, Zoltán, and Marco Spaans. “Models for Dusty Lyα Emitters at High Redshift.” <i>The Astrophysical Journal</i>, vol. 518, no. 1, American Astronomical Society, 1999, pp. 138–44, doi:<a href=\"https://doi.org/10.1086/307276\">10.1086/307276</a>.","ama":"Haiman Z, Spaans M. Models for dusty Lyα emitters at high redshift. <i>The Astrophysical Journal</i>. 1999;518(1):138-144. doi:<a href=\"https://doi.org/10.1086/307276\">10.1086/307276</a>","ista":"Haiman Z, Spaans M. 1999. Models for dusty Lyα emitters at high redshift. The Astrophysical Journal. 518(1), 138–144."},"article_processing_charge":"No","day":"10","publication_status":"published","volume":518,"OA_type":"green","_id":"17835","issue":"1","doi":"10.1086/307276","publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"scopus_import":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"Models for dusty Lyα emitters at high redshift","abstract":[{"text":"Models are presented for the Lyα emission of dusty high-redshift galaxies by combining the Press-Schechter formalism with a treatment of the inhomogeneous dust distribution inside galaxies. It is found that the amount of Lyα radiation escaping from the galaxies strongly depends on the time over which the dust is produced through stellar activity and on the ambient inhomogeneity of the H II regions that surround the ionizing OB stars. Good agreement is found with recent observations, as well as with previous nondetections. Although a detailed determination of the individual model parameters is precluded by uncertainties, we find that (1) the dust content in primordial galaxies builds up in no more than ~5 × 108 yr, (2) the galactic H II regions are inhomogeneous with a cloud-covering factor of order unity, and (3) the overall star formation efficiency is at least ~5%. It is predicted that future observations can detect these Lyα galaxies up to redshifts of ~8. If the universe is reionized at zr ≲ 8, the corresponding decline in the number of Lyα emitters at z ≳ zr could prove to be a useful probe of the reionization epoch.","lang":"eng"}],"month":"06","type":"journal_article","external_id":{"arxiv":["astro-ph/9809223"]},"year":"1999","extern":"1"},{"publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"issue":"2","doi":"10.1086/306969","scopus_import":"1","_id":"17837","external_id":{"arxiv":["astro-ph/9805258"]},"year":"1999","extern":"1","month":"04","type":"journal_article","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"Constraints from the Hubble deep field on high‐redshift quasar models","abstract":[{"text":"High-resolution, deep-imaging surveys are instrumental in setting constraints on semianalytical structure formation models in cold dark matter (CDM) cosmologies. We show here that the lack of unresolved B-band \"dropouts\" with V>25 mag in the Hubble Deep Field appears to be inconsistent with the number of \"miniquasars\" expected if massive black holes form with a constant universal efficiency in all CDM halos. To reconcile the models with the data, a mechanism is needed that suppresses the formation of active nuclei in halos with circular velocities vcirc≲50-75 km s-1. This feedback naturally arises because of the photoionization heating of the gas by the UV background. We consider several alternative effects that would help reducing the number of miniquasars and find that these cannot alone account for the observed lack of detections. If reddening by dust can be neglected at early epochs, consistency with the optical data also requires that the luminous extent of dwarf galaxies at high redshifts be larger than a few percent of the virial radii of their dark matter halos, in order not to overpredict the number of pointlike B-band dropouts. Future deep observations in the J and H bands with NICMOS might reveal several z≳5 objects per field or provide even stronger constraints on the models than existing B, V, and I data.","lang":"eng"}],"publisher":"American Astronomical Society","date_created":"2024-09-06T12:14:48Z","publication":"The Astrophysical Journal","language":[{"iso":"eng"}],"oa_version":"Preprint","page":"535-543","arxiv":1,"article_type":"original","date_updated":"2024-11-13T07:37:51Z","OA_place":"repository","intvolume":"       514","main_file_link":[{"url":"https://doi.org/10.48550/arXiv.astro-ph/9805258","open_access":"1"}],"quality_controlled":"1","status":"public","oa":1,"author":[{"orcid":"0000-0003-3633-5403","last_name":"Haiman","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","full_name":"Haiman, Zoltán","first_name":"Zoltán"},{"first_name":"Piero","full_name":"Madau, Piero","last_name":"Madau"},{"last_name":"Loeb","first_name":"Abraham","full_name":"Loeb, Abraham"}],"citation":{"mla":"Haiman, Zoltán, et al. “Constraints from the Hubble Deep Field on High‐redshift Quasar Models.” <i>The Astrophysical Journal</i>, vol. 514, no. 2, American Astronomical Society, 1999, pp. 535–43, doi:<a href=\"https://doi.org/10.1086/306969\">10.1086/306969</a>.","ama":"Haiman Z, Madau P, Loeb A. Constraints from the Hubble deep field on high‐redshift quasar models. <i>The Astrophysical Journal</i>. 1999;514(2):535-543. doi:<a href=\"https://doi.org/10.1086/306969\">10.1086/306969</a>","ista":"Haiman Z, Madau P, Loeb A. 1999. Constraints from the Hubble deep field on high‐redshift quasar models. The Astrophysical Journal. 514(2), 535–543.","short":"Z. Haiman, P. Madau, A. Loeb, The Astrophysical Journal 514 (1999) 535–543.","apa":"Haiman, Z., Madau, P., &#38; Loeb, A. (1999). Constraints from the Hubble deep field on high‐redshift quasar models. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/306969\">https://doi.org/10.1086/306969</a>","ieee":"Z. Haiman, P. Madau, and A. Loeb, “Constraints from the Hubble deep field on high‐redshift quasar models,” <i>The Astrophysical Journal</i>, vol. 514, no. 2. American Astronomical Society, pp. 535–543, 1999.","chicago":"Haiman, Zoltán, Piero Madau, and Abraham Loeb. “Constraints from the Hubble Deep Field on High‐redshift Quasar Models.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1999. <a href=\"https://doi.org/10.1086/306969\">https://doi.org/10.1086/306969</a>."},"article_processing_charge":"No","day":"01","publication_status":"published","volume":514,"OA_type":"green","date_published":"1999-04-01T00:00:00Z"},{"status":"public","oa":1,"author":[{"last_name":"Haiman","orcid":"0000-0003-3633-5403","full_name":"Haiman, Zoltán","first_name":"Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36"},{"last_name":"Loeb","full_name":"Loeb, Abraham","first_name":"Abraham"}],"OA_place":"repository","date_updated":"2024-11-13T07:43:28Z","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.astro-ph/9710208"}],"quality_controlled":"1","intvolume":"       503","page":"505-517","arxiv":1,"oa_version":"Preprint","article_type":"original","publisher":"American Astronomical Society","date_created":"2024-09-06T12:16:27Z","language":[{"iso":"eng"}],"publication":"The Astrophysical Journal","date_published":"1998-08-20T00:00:00Z","day":"20","publication_status":"published","article_processing_charge":"No","citation":{"mla":"Haiman, Zoltán, and Abraham Loeb. “Observational Signatures of the First Quasars.” <i>The Astrophysical Journal</i>, vol. 503, no. 2, American Astronomical Society, 1998, pp. 505–17, doi:<a href=\"https://doi.org/10.1086/306017\">10.1086/306017</a>.","ista":"Haiman Z, Loeb A. 1998. Observational signatures of the first quasars. The Astrophysical Journal. 503(2), 505–517.","ama":"Haiman Z, Loeb A. Observational signatures of the first quasars. <i>The Astrophysical Journal</i>. 1998;503(2):505-517. doi:<a href=\"https://doi.org/10.1086/306017\">10.1086/306017</a>","short":"Z. Haiman, A. Loeb, The Astrophysical Journal 503 (1998) 505–517.","ieee":"Z. Haiman and A. Loeb, “Observational signatures of the first quasars,” <i>The Astrophysical Journal</i>, vol. 503, no. 2. American Astronomical Society, pp. 505–517, 1998.","chicago":"Haiman, Zoltán, and Abraham Loeb. “Observational Signatures of the First Quasars.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1998. <a href=\"https://doi.org/10.1086/306017\">https://doi.org/10.1086/306017</a>.","apa":"Haiman, Z., &#38; Loeb, A. (1998). Observational signatures of the first quasars. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/306017\">https://doi.org/10.1086/306017</a>"},"OA_type":"green","volume":503,"_id":"17839","issue":"2","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"doi":"10.1086/306017","scopus_import":"1","title":"Observational signatures of the first quasars","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","abstract":[{"text":"We study the observational signatures of a potential population of low-luminosity quasars at high redshifts in a ΛCDM cosmology. We derive the evolution of the quasar luminosity function at fainter luminosities and higher redshifts than currently detected based on three assumptions: (1) the formation of dark matter halos follows the Press-Schechter theory, (2) the ratio of central black hole mass to halo mass is the same for all halos, and (3) the light curve of quasars, in Eddington units, is universal. We show that a universal light curve provides an excellent fit to the observed quasar luminosity function at redshifts 2.6 < z < 4.5. By extrapolating the evolution of this luminosity function to higher redshifts (4.5 < z < 20), we find that the associated early population of low-luminosity quasars reionizes the universe at a redshift z ~ 12. The reprocessing of the UV light of these quasars by dust from early Type II supernovae distorts the microwave background spectrum by a Compton y-parameter y ~ 10-5, comparable to the lower limit set by COBE. The Next Generation Space Telescope could detect tens of quasars per arcmin-2 from redshifts z > 10 with its proposed 1 nJy sensitivity at 1-3.5 μm. Absorption spectra of several such quasars would reveal the reionization history of the universe.","lang":"eng"}],"type":"journal_article","month":"08","year":"1998","extern":"1","external_id":{"arxiv":["astro-ph/9710208"]}},{"date_published":"1997-02-20T00:00:00Z","citation":{"ista":"Haiman Z, Rees MJ, Loeb A. 1997. Destruction of molecular hydrogen during cosmological reionization. The Astrophysical Journal. 476(2), 458–463.","ama":"Haiman Z, Rees MJ, Loeb A. Destruction of molecular hydrogen during cosmological reionization. <i>The Astrophysical Journal</i>. 1997;476(2):458-463. doi:<a href=\"https://doi.org/10.1086/303647\">10.1086/303647</a>","mla":"Haiman, Zoltán, et al. “Destruction of Molecular Hydrogen during Cosmological Reionization.” <i>The Astrophysical Journal</i>, vol. 476, no. 2, American Astronomical Society, 1997, pp. 458–63, doi:<a href=\"https://doi.org/10.1086/303647\">10.1086/303647</a>.","short":"Z. Haiman, M.J. Rees, A. Loeb, The Astrophysical Journal 476 (1997) 458–463.","apa":"Haiman, Z., Rees, M. J., &#38; Loeb, A. (1997). Destruction of molecular hydrogen during cosmological reionization. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/303647\">https://doi.org/10.1086/303647</a>","ieee":"Z. Haiman, M. J. Rees, and A. Loeb, “Destruction of molecular hydrogen during cosmological reionization,” <i>The Astrophysical Journal</i>, vol. 476, no. 2. American Astronomical Society, pp. 458–463, 1997.","chicago":"Haiman, Zoltán, Martin J. Rees, and Abraham Loeb. “Destruction of Molecular Hydrogen during Cosmological Reionization.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1997. <a href=\"https://doi.org/10.1086/303647\">https://doi.org/10.1086/303647</a>."},"article_processing_charge":"No","publication_status":"published","day":"20","volume":476,"OA_type":"green","status":"public","author":[{"full_name":"Haiman, Zoltán","first_name":"Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","last_name":"Haiman","orcid":"0000-0003-3633-5403"},{"first_name":"Martin J.","full_name":"Rees, Martin J.","last_name":"Rees"},{"last_name":"Loeb","full_name":"Loeb, Abraham","first_name":"Abraham"}],"oa":1,"date_updated":"2024-11-12T12:35:58Z","OA_place":"repository","main_file_link":[{"url":"https://doi.org/10.48550/arXiv.astro-ph/9608130","open_access":"1"}],"intvolume":"       476","quality_controlled":"1","oa_version":"Preprint","arxiv":1,"page":"458-463","article_type":"original","publisher":"American Astronomical Society","date_created":"2024-09-06T11:51:44Z","publication":"The Astrophysical Journal","language":[{"iso":"eng"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"Destruction of molecular hydrogen during cosmological reionization","abstract":[{"text":"We investigate the ability of primordial gas clouds to retain molecular hydrogen (H2) during the initial phase of the reionization epoch. We find that before the Strömgren spheres of the individual ionizing sources overlap, the UV background below the ionization threshold is able to penetrate large clouds and suppress their H2 abundance. The consequent lack of H2 cooling could prevent the collapse and fragmentation of clouds with virial temperatures Tvir ≲ 10^4 K (or masses ≲10^8 M☉[(1 + zvir)/10]-^3/2). This negative feedback on structure formation arises from the very first ionizing sources and precedes the feedback due to the photoionization heating.","lang":"eng"}],"month":"02","type":"journal_article","external_id":{"arxiv":["astro-ph/9608130"]},"extern":"1","year":"1997","_id":"17821","doi":"10.1086/303647","publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"issue":"2","scopus_import":"1"},{"type":"journal_article","month":"12","extern":"1","year":"1997","external_id":{"arxiv":["astro-ph/9704133"]},"title":"Signatures of intergalactic dust from the first supernovae","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","abstract":[{"lang":"eng","text":"We quantify the consequences of intergalactic dust produced by the first Type II supernovae in the universe. The fraction of gas converted into stars is calibrated based on the observed C/H ratio in the intergalactic medium at z = 3, assuming a Scalo mass function for the stars. The associated dust absorbs starlight energy and emits it at longer wavelengths. For a uniform mix of metals and dust with the intergalactic gas, we find that the dust distorts the microwave background spectrum by a y-parameter in the range (0.06-6) × 10-5 (MSN/0.3 M☉), where MSN is the average mass of dust produced per supernova. The opacity of intergalactic dust to infrared sources at redshifts of z ≳ 10 is significant, τdust = (0.1-1) × (MSN/0.3 M☉), and could be detected with the Next Generation Space Telescope. Although dust suppresses the Lyα emission from early sources, the redshifts of star clusters at z = 10-35 can be easily inferred from the Lyman limit break in their infrared spectrum between 1 and 3.5 μm."}],"issue":"2","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"doi":"10.1086/304919","scopus_import":"1","_id":"17828","date_published":"1997-12-01T00:00:00Z","publication_status":"published","day":"01","citation":{"short":"A. Loeb, Z. Haiman, The Astrophysical Journal 490 (1997) 571–576.","mla":"Loeb, Abraham, and Zoltán Haiman. “Signatures of Intergalactic Dust from the First Supernovae.” <i>The Astrophysical Journal</i>, vol. 490, no. 2, American Astronomical Society, 1997, pp. 571–76, doi:<a href=\"https://doi.org/10.1086/304919\">10.1086/304919</a>.","ista":"Loeb A, Haiman Z. 1997. Signatures of intergalactic dust from the first supernovae. The Astrophysical Journal. 490(2), 571–576.","ama":"Loeb A, Haiman Z. Signatures of intergalactic dust from the first supernovae. <i>The Astrophysical Journal</i>. 1997;490(2):571-576. doi:<a href=\"https://doi.org/10.1086/304919\">10.1086/304919</a>","chicago":"Loeb, Abraham, and Zoltán Haiman. “Signatures of Intergalactic Dust from the First Supernovae.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1997. <a href=\"https://doi.org/10.1086/304919\">https://doi.org/10.1086/304919</a>.","apa":"Loeb, A., &#38; Haiman, Z. (1997). Signatures of intergalactic dust from the first supernovae. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/304919\">https://doi.org/10.1086/304919</a>","ieee":"A. Loeb and Z. Haiman, “Signatures of intergalactic dust from the first supernovae,” <i>The Astrophysical Journal</i>, vol. 490, no. 2. American Astronomical Society, pp. 571–576, 1997."},"article_processing_charge":"No","OA_type":"green","volume":490,"arxiv":1,"page":"571-576","oa_version":"Preprint","article_type":"original","publisher":"American Astronomical Society","date_created":"2024-09-06T12:08:42Z","language":[{"iso":"eng"}],"publication":"The Astrophysical Journal","status":"public","oa":1,"author":[{"last_name":"Loeb","first_name":"Abraham","full_name":"Loeb, Abraham"},{"orcid":"0000-0003-3633-5403","last_name":"Haiman","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","full_name":"Haiman, Zoltán","first_name":"Zoltán"}],"OA_place":"repository","date_updated":"2024-11-13T07:14:38Z","intvolume":"       490","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.astro-ph/9704133"}],"quality_controlled":"1"},{"OA_place":"repository","date_updated":"2024-11-13T07:53:11Z","intvolume":"       483","main_file_link":[{"url":"https://doi.org/10.48550/arXiv.astro-ph/9611028","open_access":"1"}],"quality_controlled":"1","status":"public","oa":1,"author":[{"id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","first_name":"Zoltán","full_name":"Haiman, Zoltán","last_name":"Haiman","orcid":"0000-0003-3633-5403"},{"last_name":"Loeb","first_name":"Abraham","full_name":"Loeb, Abraham"}],"publisher":"American Astronomical Society","date_created":"2024-09-06T12:25:48Z","language":[{"iso":"eng"}],"publication":"The Astrophysical Journal","page":"21-37","arxiv":1,"oa_version":"Preprint","article_type":"original","day":"01","publication_status":"published","article_processing_charge":"No","citation":{"ama":"Haiman Z, Loeb A. Signatures of stellar reionization of the universe. <i>The Astrophysical Journal</i>. 1997;483(1):21-37. doi:<a href=\"https://doi.org/10.1086/304238\">10.1086/304238</a>","ista":"Haiman Z, Loeb A. 1997. Signatures of stellar reionization of the universe. The Astrophysical Journal. 483(1), 21–37.","mla":"Haiman, Zoltán, and Abraham Loeb. “Signatures of Stellar Reionization of the Universe.” <i>The Astrophysical Journal</i>, vol. 483, no. 1, American Astronomical Society, 1997, pp. 21–37, doi:<a href=\"https://doi.org/10.1086/304238\">10.1086/304238</a>.","short":"Z. Haiman, A. Loeb, The Astrophysical Journal 483 (1997) 21–37.","ieee":"Z. Haiman and A. Loeb, “Signatures of stellar reionization of the universe,” <i>The Astrophysical Journal</i>, vol. 483, no. 1. American Astronomical Society, pp. 21–37, 1997.","apa":"Haiman, Z., &#38; Loeb, A. (1997). Signatures of stellar reionization of the universe. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/304238\">https://doi.org/10.1086/304238</a>","chicago":"Haiman, Zoltán, and Abraham Loeb. “Signatures of Stellar Reionization of the Universe.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1997. <a href=\"https://doi.org/10.1086/304238\">https://doi.org/10.1086/304238</a>."},"OA_type":"green","volume":483,"date_published":"1997-07-01T00:00:00Z","_id":"17848","doi":"10.1086/304238","publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"issue":"1","scopus_import":"1","title":"Signatures of stellar reionization of the universe","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","abstract":[{"lang":"eng","text":"The high ionization level and nonzero metallicity (~1% Z☉) of the intergalactic gas at redshifts z ≲ 5 implies that nonlinear structure had started to form in the universe at earlier times than we currently probe. In cold dark matter (CDM) cosmologies, the first generation of baryonic objects emerges at redshifts z ~ 10-50. Here we examine the observable consequences of the possibility that an early generation of stars reionized the universe and resulted in the observed metallicity of the Lyα forest. Forthcoming microwave anisotropy experiments will be sensitive to the damping of anisotropies caused by scattering off free electrons from the reionization epoch. For a large range of CDM models with a Scalo stellar mass function, we find that reionization occurs at a redshift z ≳ 10 and damps the amplitude of anisotropies on angular scales ≲10° by a detectable amount, ~10%-25%. However, reionization is substantially delayed if the initial stellar mass function transformed most of the baryons into low-mass stars. In this case, the mass fraction of pregalactic stars could be constrained from the statistics of microlensing events in galactic halos or along lines of sight to quasars. Deep infrared imaging with future space telescopes (such as the Space Infrared Telescope Facility or the Next Generation Space Telescope) will be able to detect bright star clusters at z ≳ 5. The cumulative bremsstrahlung emission from these star clusters yields a measurable distortion to the spectrum of the microwave background."}],"year":"1997","extern":"1","external_id":{"arxiv":["astro-ph/9611028"]},"type":"journal_article","month":"07"},{"day":"01","publication_status":"published","citation":{"ieee":"Z. Haiman, M. J. Rees, and A. Loeb, “H 2 cooling of primordial gas triggered by UV irradiation,” <i>The Astrophysical Journal</i>, vol. 467. American Astronomical Society, 1996.","chicago":"Haiman, Zoltán, Martin J. Rees, and Abraham Loeb. “H 2 Cooling of Primordial Gas Triggered by UV Irradiation.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1996. <a href=\"https://doi.org/10.1086/177628\">https://doi.org/10.1086/177628</a>.","apa":"Haiman, Z., Rees, M. J., &#38; Loeb, A. (1996). H 2 cooling of primordial gas triggered by UV irradiation. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/177628\">https://doi.org/10.1086/177628</a>","short":"Z. Haiman, M.J. Rees, A. Loeb, The Astrophysical Journal 467 (1996).","ista":"Haiman Z, Rees MJ, Loeb A. 1996. H 2 cooling of primordial gas triggered by UV irradiation. The Astrophysical Journal. 467, 522.","ama":"Haiman Z, Rees MJ, Loeb A. H 2 cooling of primordial gas triggered by UV irradiation. <i>The Astrophysical Journal</i>. 1996;467. doi:<a href=\"https://doi.org/10.1086/177628\">10.1086/177628</a>","mla":"Haiman, Zoltán, et al. “H 2 Cooling of Primordial Gas Triggered by UV Irradiation.” <i>The Astrophysical Journal</i>, vol. 467, 522, American Astronomical Society, 1996, doi:<a href=\"https://doi.org/10.1086/177628\">10.1086/177628</a>."},"article_processing_charge":"No","volume":467,"date_published":"1996-08-01T00:00:00Z","date_created":"2024-09-06T11:54:20Z","publisher":"American Astronomical Society","language":[{"iso":"eng"}],"publication":"The Astrophysical Journal","oa_version":"Preprint","article_type":"original","date_updated":"2024-12-10T09:18:05Z","quality_controlled":"1","intvolume":"       467","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.astro-ph/9511126"}],"status":"public","author":[{"id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","full_name":"Haiman, Zoltán","first_name":"Zoltán","orcid":"0000-0003-3633-5403","last_name":"Haiman"},{"full_name":"Rees, Martin J.","first_name":"Martin J.","last_name":"Rees"},{"first_name":"Abraham","full_name":"Loeb, Abraham","last_name":"Loeb"}],"oa":1,"extern":"1","year":"1996","external_id":{"unknown":["astro-ph/9511126"]},"type":"journal_article","month":"08","article_number":"522","title":"H 2 cooling of primordial gas triggered by UV irradiation","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","abstract":[{"text":"We investigate the formation of molecular hydrogen (H_2_) in a primordial H + He gas cloud irradiated by a power-law UV flux. We find that at high densities (~>1 cm^-3^) and low temperatures (<~10^4^ K), the background radiation enhances the formation of H_2_ and results in molecular cooling dominating over photoionization heating. This process could accelerate the collapse and fragmentation of dense objects at high redshifts.","lang":"eng"}],"publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"doi":"10.1086/177628","scopus_import":"1","_id":"17822"},{"month":"06","type":"journal_article","external_id":{"arxiv":["astro-ph/9507111"]},"extern":"1","year":"1996","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"Cosmological formation of low-mass objects","abstract":[{"lang":"eng","text":"We investigate the early formation of bound objects with masses comparable to the cosmological Jeans mass (~10^5^ M_sun_). We follow the growth of isolated spherically symmetric density peaks starting from the linear perturbative regime. The initial parameters correspond to density peaks of various widths and heights in a cold dark matter cosmology. We use a one-dimensional spherical Lagrangian hydrodynamics code to follow the dynamical, thermal, and nonequilibrium chemical evolution of the gas. The system includes a collisionless dark matter component and a baryonic component composed of the nine species H, H^-^, H^+^, He, He^+^, He^++^, H_2_, H_2_^+^, and e^-^. All relevant chemical reactions between these species and their cooling mechanisms are included in the calculations. We explore the dependence of the dynamical evolution of the gas on two parameters: the initial mass scale and the initial overdensity of the system. We follow the evolution of the density, temperature, and abundance profiles within the cloud, assuming two types of central boundary conditions for the collisionless component: in one the infalling dark matter virializes through a reflection from a hard sphere, while in the other it accretes onto a central sink. We find that in both cases, radiative cooling by H_2_ affects the collapse dynamics of the gas only after it has already virialized and become part of the bound object. Therefore, radiative cooling is unlikely to have triggered the initial collapse of perturbations at redshifts z > 10. Nevertheless, baryonic objects with masses well below the linear theory Jeans mass (<~10^3^ M_sun_) form at high redshifts because of shell crossing by the dark matter. Such objects could be the progenitors of a primordial population of high-mass stars in the intergalactic medium."}],"article_number":"523","doi":"10.1086/177343","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"scopus_import":"1","_id":"17834","date_published":"1996-06-01T00:00:00Z","article_processing_charge":"No","citation":{"chicago":"Haiman, Zoltán, Anne A. Thoul, and Abraham Loeb. “Cosmological Formation of Low-Mass Objects.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1996. <a href=\"https://doi.org/10.1086/177343\">https://doi.org/10.1086/177343</a>.","apa":"Haiman, Z., Thoul, A. A., &#38; Loeb, A. (1996). Cosmological formation of low-mass objects. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/177343\">https://doi.org/10.1086/177343</a>","ieee":"Z. Haiman, A. A. Thoul, and A. Loeb, “Cosmological formation of low-mass objects,” <i>The Astrophysical Journal</i>, vol. 464. American Astronomical Society, 1996.","mla":"Haiman, Zoltán, et al. “Cosmological Formation of Low-Mass Objects.” <i>The Astrophysical Journal</i>, vol. 464, 523, American Astronomical Society, 1996, doi:<a href=\"https://doi.org/10.1086/177343\">10.1086/177343</a>.","ama":"Haiman Z, Thoul AA, Loeb A. Cosmological formation of low-mass objects. <i>The Astrophysical Journal</i>. 1996;464. doi:<a href=\"https://doi.org/10.1086/177343\">10.1086/177343</a>","ista":"Haiman Z, Thoul AA, Loeb A. 1996. Cosmological formation of low-mass objects. The Astrophysical Journal. 464, 523.","short":"Z. Haiman, A.A. Thoul, A. Loeb, The Astrophysical Journal 464 (1996)."},"day":"01","publication_status":"published","volume":464,"OA_type":"green","oa_version":"Preprint","arxiv":1,"article_type":"original","publisher":"American Astronomical Society","date_created":"2024-09-06T12:12:52Z","publication":"The Astrophysical Journal","language":[{"iso":"eng"}],"status":"public","author":[{"orcid":"0000-0003-3633-5403","last_name":"Haiman","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","first_name":"Zoltán","full_name":"Haiman, Zoltán"},{"last_name":"Thoul","first_name":"Anne A.","full_name":"Thoul, Anne A."},{"last_name":"Loeb","full_name":"Loeb, Abraham","first_name":"Abraham"}],"oa":1,"date_updated":"2025-01-03T11:34:15Z","OA_place":"repository","intvolume":"       464","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/astro-ph/9507111"}],"quality_controlled":"1"}]