[{"doi":"10.3847/1538-3881/ab8f8c","status":"public","main_file_link":[{"open_access":"1","url":"https://doi.org/10.3847/1538-3881/ab8f8c"}],"citation":{"ieee":"J. M. Z. Matilla, S. Waterval, and Z. Haiman, “Optimizing simulation parameters for weak lensing analyses involving non-Gaussian observables,” <i>The Astronomical Journal</i>, vol. 159, no. 6. American Astronomical Society, 2020.","short":"J.M.Z. Matilla, S. Waterval, Z. Haiman, The Astronomical Journal 159 (2020).","ista":"Matilla JMZ, Waterval S, Haiman Z. 2020. Optimizing simulation parameters for weak lensing analyses involving non-Gaussian observables. The Astronomical Journal. 159(6), 284.","chicago":"Matilla, José Manuel Zorrilla, Stefan Waterval, and Zoltán Haiman. “Optimizing Simulation Parameters for Weak Lensing Analyses Involving Non-Gaussian Observables.” <i>The Astronomical Journal</i>. American Astronomical Society, 2020. <a href=\"https://doi.org/10.3847/1538-3881/ab8f8c\">https://doi.org/10.3847/1538-3881/ab8f8c</a>.","ama":"Matilla JMZ, Waterval S, Haiman Z. Optimizing simulation parameters for weak lensing analyses involving non-Gaussian observables. <i>The Astronomical Journal</i>. 2020;159(6). doi:<a href=\"https://doi.org/10.3847/1538-3881/ab8f8c\">10.3847/1538-3881/ab8f8c</a>","mla":"Matilla, José Manuel Zorrilla, et al. “Optimizing Simulation Parameters for Weak Lensing Analyses Involving Non-Gaussian Observables.” <i>The Astronomical Journal</i>, vol. 159, no. 6, 284, American Astronomical Society, 2020, doi:<a href=\"https://doi.org/10.3847/1538-3881/ab8f8c\">10.3847/1538-3881/ab8f8c</a>.","apa":"Matilla, J. M. Z., Waterval, S., &#38; Haiman, Z. (2020). Optimizing simulation parameters for weak lensing analyses involving non-Gaussian observables. <i>The Astronomical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.3847/1538-3881/ab8f8c\">https://doi.org/10.3847/1538-3881/ab8f8c</a>"},"date_published":"2020-05-29T00:00:00Z","type":"journal_article","oa_version":"Published Version","abstract":[{"text":"We performed a series of numerical experiments to quantify the sensitivity of the predictions for weak lensing statistics obtained in ray-tracing dark matter (DM)-only simulations, to two hyper-parameters that influence the accuracy as well as the computational cost of the predictions: the thickness of the lens planes used to build past light cones and the mass resolution of the underlying DM simulation. The statistics considered are the power spectrum (PS) and a series of non-Gaussian observables, including the one-point probability density function, lensing peaks, and Minkowski functionals. Counterintuitively, we find that using thin lens planes (< 60 h−1 Mpc on a 240 h−1 Mpc simulation box) suppresses the PS over a broad range of scales beyond what would be acceptable for a survey comparable to the Large Synoptic Survey Telescope (LSST). A mass resolution of 7.2 × 1011 h−1 M⊙ per DM particle (or 2563 particles in a (240 h−1 Mpc)3 box) is sufficient to extract information using the PS and non-Gaussian statistics from weak lensing data at angular scales down to 1' with LSST-like levels of shape noise.","lang":"eng"}],"month":"05","publication_status":"published","issue":"6","fulldoi":"https://doi.org/10.3847/1538-3881/ab8f8c","date_updated":"2024-09-11T09:03:15Z","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","article_processing_charge":"No","article_number":"284","extern":"1","_id":"17528","date_created":"2024-09-05T09:35:49Z","author":[{"full_name":"Matilla, José Manuel Zorrilla","last_name":"Matilla","first_name":"José Manuel Zorrilla"},{"full_name":"Waterval, Stefan","last_name":"Waterval","first_name":"Stefan"},{"full_name":"Haiman, Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","last_name":"Haiman","first_name":"Zoltán"}],"article_type":"original","title":"Optimizing simulation parameters for weak lensing analyses involving non-Gaussian observables","quality_controlled":"1","scopus_import":"1","publication_identifier":{"issn":["0004-6256","1538-3881"]},"publisher":"American Astronomical Society","day":"29","volume":159,"publication":"The Astronomical Journal","intvolume":"       159","oa":1,"language":[{"iso":"eng"}],"year":"2020"},{"fulldoi":"https://doi.org/10.1088/0004-6256/148/4/73","date_updated":"2024-09-25T09:51:31Z","issue":"4","publication_status":"published","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","article_processing_charge":"No","article_number":"73","doi":"10.1088/0004-6256/148/4/73","main_file_link":[{"url":"https://doi.org/10.1088/0004-6256/148/4/73","open_access":"1"}],"status":"public","citation":{"ama":"McGreer ID, Fan X, Strauss MA, et al. Close companions to two high-redshift quasars. <i>The Astronomical Journal</i>. 2014;148(4). doi:<a href=\"https://doi.org/10.1088/0004-6256/148/4/73\">10.1088/0004-6256/148/4/73</a>","ista":"McGreer ID, Fan X, Strauss MA, Haiman Z, Richards GT, Jiang L, Bian F, Schneider DP. 2014. Close companions to two high-redshift quasars. The Astronomical Journal. 148(4), 73.","chicago":"McGreer, Ian D., Xiaohui Fan, Michael A. Strauss, Zoltán Haiman, Gordon T. Richards, Linhua Jiang, Fuyan Bian, and Donald P. Schneider. “Close Companions to Two High-Redshift Quasars.” <i>The Astronomical Journal</i>. American Astronomical Society, 2014. <a href=\"https://doi.org/10.1088/0004-6256/148/4/73\">https://doi.org/10.1088/0004-6256/148/4/73</a>.","short":"I.D. McGreer, X. Fan, M.A. Strauss, Z. Haiman, G.T. Richards, L. Jiang, F. Bian, D.P. Schneider, The Astronomical Journal 148 (2014).","ieee":"I. D. McGreer <i>et al.</i>, “Close companions to two high-redshift quasars,” <i>The Astronomical Journal</i>, vol. 148, no. 4. American Astronomical Society, 2014.","mla":"McGreer, Ian D., et al. “Close Companions to Two High-Redshift Quasars.” <i>The Astronomical Journal</i>, vol. 148, no. 4, 73, American Astronomical Society, 2014, doi:<a href=\"https://doi.org/10.1088/0004-6256/148/4/73\">10.1088/0004-6256/148/4/73</a>.","apa":"McGreer, I. D., Fan, X., Strauss, M. A., Haiman, Z., Richards, G. T., Jiang, L., … Schneider, D. P. (2014). Close companions to two high-redshift quasars. <i>The Astronomical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1088/0004-6256/148/4/73\">https://doi.org/10.1088/0004-6256/148/4/73</a>"},"date_published":"2014-09-15T00:00:00Z","type":"journal_article","oa_version":"Published Version","abstract":[{"lang":"eng","text":"We report the serendipitous discoveries of companion galaxies to two high-redshift quasars. SDSS J025617.7+001904 is a z=4.79 quasar included in our recent survey of faint quasars in the SDSS Stripe 82 region. The initial MMT slit spectroscopy shows excess Lyman alpha emission extending well beyond the quasar's light profile. Further imaging and spectroscopy with LBT/MODS1 confirms the presence of a bright galaxy (i_AB = 23.6) located 2arcsec (12 kpc projected) from the quasar with strong Lyman alpha emission (EW_0 ~ 100Ang) at the redshift of the quasar, as well as faint continuum. The second quasar, CFHQS J005006.6+344522 (z=6.25), is included in our recent HST SNAP survey of z~6 quasars searching for evidence of gravitational lensing. Deep imaging with ACS and WFC3 confirms an optical dropout ~4.5 mag fainter than the quasar (Y_AB=25) at a separation of 0.9 arcsec. The red i_775-Y_105 color of the galaxy and its proximity to the quasar (5 kpc projected if at the quasar redshift) strongly favor an association with the quasar. Although it is much fainter than the quasar it is remarkably bright when compared to field galaxies at this redshift, while showing no evidence for lensing. Both systems may represent late-stage mergers of two massive galaxies, with the observed light for one dominated by powerful ongoing star formation and for the other by rapid black hole growth. Observations of close companions are rare; if major mergers are primarily responsible for high-redshift quasar fueling then the phase when progenitor galaxies can be observed as bright companions is relatively short."}],"month":"09","day":"15","volume":148,"publication":"The Astronomical Journal","intvolume":"       148","oa":1,"language":[{"iso":"eng"}],"year":"2014","_id":"17689","date_created":"2024-09-06T08:24:25Z","extern":"1","article_type":"original","author":[{"first_name":"Ian D.","last_name":"McGreer","full_name":"McGreer, Ian D."},{"first_name":"Xiaohui","last_name":"Fan","full_name":"Fan, Xiaohui"},{"first_name":"Michael A.","full_name":"Strauss, Michael A.","last_name":"Strauss"},{"last_name":"Haiman","full_name":"Haiman, Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","first_name":"Zoltán"},{"full_name":"Richards, Gordon T.","last_name":"Richards","first_name":"Gordon T."},{"last_name":"Jiang","full_name":"Jiang, Linhua","first_name":"Linhua"},{"last_name":"Bian","full_name":"Bian, Fuyan","first_name":"Fuyan"},{"full_name":"Schneider, Donald P.","last_name":"Schneider","first_name":"Donald P."}],"quality_controlled":"1","title":"Close companions to two high-redshift quasars","scopus_import":"1","publisher":"American Astronomical Society","publication_identifier":{"issn":["1538-3881"]}},{"article_processing_charge":"No","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","publication_status":"published","issue":"2","fulldoi":"https://doi.org/10.1088/0004-6256/140/2/642","date_updated":"2024-09-25T09:22:09Z","month":"07","abstract":[{"text":"The coalescence of a supermassive black hole binary (SMBHB) is thought to be accompanied by an electromagnetic (EM) afterglow, produced by the viscous infall of the surrounding circumbinary gas disk after the merger. It has been proposed that once the merger has been detected in gravitational waves (GWs) by LISA, follow-up EM searches for this afterglow can help identify the EM counterpart of the LISA source. Here we study whether the afterglows may be sufficiently bright and numerous to be detectable in EM surveys alone. The viscous afterglow, which lasts for years to decades for SMBHBs in LISA's sensitivity window, is characterized by rapid increases in both the bolometric luminosity and in the spectral hardness of the source. If quasar activity is triggered by the same major galaxy mergers that produce SMBHBs, then the afterglow could be interpreted as a signature of the birth of a quasar. Using an idealized model for the post-merger viscous spreading of the circumbinary disk and the resulting light curve, and using the observed luminosity function of quasars as a proxy for the SMBHB merger rate, we delineate the survey requirements for identifying such birthing quasars. If circumbinary disks have a high disk surface density and viscosity, an all-sky soft X-ray survey with a sensitivity of ~<3x10^-14 erg s^-1 cm^-2 and a time resolution of ~months could identify dozens of birthing quasars with sustained brightening rates of >10%/yr. If >1% of the X-ray emission is reprocessed into optical frequencies, birthing quasars could also be identified in optical transient surveys such as the LSST. Distinguishing a birthing quasar from other variable sources may be facilitated by the monotonic hardening of its spectrum, but will likely remain challenging. This reinforces the notion that joint EM-plus-GW observations offer the best prospects for identifying the EM signatures of SMBHB mergers.","lang":"eng"}],"oa_version":"Published Version","type":"journal_article","date_published":"2010-07-15T00:00:00Z","citation":{"chicago":"Tanaka, Takamitsu, Zoltán Haiman, and Kristen Menou. “Witnessing the Birth of a Quasar.” <i>The Astronomical Journal</i>. American Astronomical Society, 2010. <a href=\"https://doi.org/10.1088/0004-6256/140/2/642\">https://doi.org/10.1088/0004-6256/140/2/642</a>.","ista":"Tanaka T, Haiman Z, Menou K. 2010. Witnessing the birth of a quasar. The Astronomical Journal. 140(2), 642–651.","ama":"Tanaka T, Haiman Z, Menou K. Witnessing the birth of a quasar. <i>The Astronomical Journal</i>. 2010;140(2):642-651. doi:<a href=\"https://doi.org/10.1088/0004-6256/140/2/642\">10.1088/0004-6256/140/2/642</a>","ieee":"T. Tanaka, Z. Haiman, and K. Menou, “Witnessing the birth of a quasar,” <i>The Astronomical Journal</i>, vol. 140, no. 2. American Astronomical Society, pp. 642–651, 2010.","short":"T. Tanaka, Z. Haiman, K. Menou, The Astronomical Journal 140 (2010) 642–651.","apa":"Tanaka, T., Haiman, Z., &#38; Menou, K. (2010). Witnessing the birth of a quasar. <i>The Astronomical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1088/0004-6256/140/2/642\">https://doi.org/10.1088/0004-6256/140/2/642</a>","mla":"Tanaka, Takamitsu, et al. “Witnessing the Birth of a Quasar.” <i>The Astronomical Journal</i>, vol. 140, no. 2, American Astronomical Society, 2010, pp. 642–51, doi:<a href=\"https://doi.org/10.1088/0004-6256/140/2/642\">10.1088/0004-6256/140/2/642</a>."},"status":"public","main_file_link":[{"url":"https://doi.org/10.1088/0004-6256/140/2/642","open_access":"1"}],"doi":"10.1088/0004-6256/140/2/642","year":"2010","language":[{"iso":"eng"}],"oa":1,"intvolume":"       140","publication":"The Astronomical Journal","volume":140,"day":"15","publication_identifier":{"issn":["0004-6256","1538-3881"]},"publisher":"American Astronomical Society","scopus_import":"1","title":"Witnessing the birth of a quasar","quality_controlled":"1","article_type":"original","author":[{"first_name":"Takamitsu","full_name":"Tanaka, Takamitsu","last_name":"Tanaka"},{"first_name":"Zoltán","last_name":"Haiman","full_name":"Haiman, Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36"},{"first_name":"Kristen","last_name":"Menou","full_name":"Menou, Kristen"}],"extern":"1","_id":"17686","date_created":"2024-09-06T08:21:37Z","page":"642-651"},{"article_processing_charge":"No","issue":"1","publication_status":"published","fulldoi":"https://doi.org/10.1086/498063","date_updated":"2024-11-12T09:57:35Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","type":"journal_article","oa_version":"Published Version","related_material":{"link":[{"relation":"erratum","url":"https://doi.org/10.1086/506907"}]},"abstract":[{"text":"We report on i-band snapshot observations of 157 Sloan Digital Sky Survey (SDSS) quasars at 4<z<5.4 using the Advanced Camera for Surveys on the Hubble Space Telescope (HST) to search for evidence of gravitational lensing of these sources. None of the quasars appear to be strongly lensed and multiply imaged at the angular resolution (~0.1\") and sensitivity of HST. The non-detection of strong lensing in these systems constrains the z=4-5 luminosity function to an intrinsic slope of beta>-3.8 (3 sigma), assuming a break in the quasar luminosity function at M*_145=-24.5. This constraint is considerably stronger than the limit of beta>-4.63 obtained from the absence of lensing in four z>5.7 quasars. Such constraints are important for our understanding of the true space density of high-redshift quasars and the ionization state of the early universe.","lang":"eng"}],"month":"01","doi":"10.1086/498063","status":"public","main_file_link":[{"url":"https://doi.org/10.1086/498063","open_access":"1"}],"citation":{"short":"G.T. Richards, Z. Haiman, B. Pindor, M.A. Strauss, X. Fan, D. Eisenstein, D.P. Schneider, N.A. Bahcall, J. Brinkmann, M. Fukugita, The Astronomical Journal 131 (2006) 49–54.","ieee":"G. T. Richards <i>et al.</i>, “A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. II. Constraints on the 4.0 &#60; z &#60; 5.4 quasar population,” <i>The Astronomical Journal</i>, vol. 131, no. 1. American Astronomical Society, pp. 49–54, 2006.","ama":"Richards GT, Haiman Z, Pindor B, et al. A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. II. Constraints on the 4.0 &#60; z &#60; 5.4 quasar population. <i>The Astronomical Journal</i>. 2006;131(1):49-54. doi:<a href=\"https://doi.org/10.1086/498063\">10.1086/498063</a>","chicago":"Richards, Gordon T., Zoltán Haiman, Bartosz Pindor, Michael A. Strauss, Xiaohui Fan, Daniel Eisenstein, Donald P. Schneider, Neta A. Bahcall, J. Brinkmann, and Masataka Fukugita. “A Snapshot Survey for Gravitational Lenses among z ≥ 4.0 Quasars. II. Constraints on the 4.0 &#60; z &#60; 5.4 Quasar Population.” <i>The Astronomical Journal</i>. American Astronomical Society, 2006. <a href=\"https://doi.org/10.1086/498063\">https://doi.org/10.1086/498063</a>.","ista":"Richards GT, Haiman Z, Pindor B, Strauss MA, Fan X, Eisenstein D, Schneider DP, Bahcall NA, Brinkmann J, Fukugita M. 2006. A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. II. Constraints on the 4.0 &#60; z &#60; 5.4 quasar population. The Astronomical Journal. 131(1), 49–54.","mla":"Richards, Gordon T., et al. “A Snapshot Survey for Gravitational Lenses among z ≥ 4.0 Quasars. II. Constraints on the 4.0 &#60; z &#60; 5.4 Quasar Population.” <i>The Astronomical Journal</i>, vol. 131, no. 1, American Astronomical Society, 2006, pp. 49–54, doi:<a href=\"https://doi.org/10.1086/498063\">10.1086/498063</a>.","apa":"Richards, G. T., Haiman, Z., Pindor, B., Strauss, M. A., Fan, X., Eisenstein, D., … Fukugita, M. (2006). A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. II. Constraints on the 4.0 &#60; z &#60; 5.4 quasar population. <i>The Astronomical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/498063\">https://doi.org/10.1086/498063</a>"},"date_published":"2006-01-01T00:00:00Z","intvolume":"       131","oa":1,"language":[{"iso":"eng"}],"year":"2006","day":"01","volume":131,"publication":"The Astronomical Journal","article_type":"original","author":[{"first_name":"Gordon T.","last_name":"Richards","full_name":"Richards, Gordon T."},{"orcid":"0000-0003-3633-5403","first_name":"Zoltán","full_name":"Haiman, Zoltán","last_name":"Haiman","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36"},{"last_name":"Pindor","full_name":"Pindor, Bartosz","first_name":"Bartosz"},{"first_name":"Michael A.","full_name":"Strauss, Michael A.","last_name":"Strauss"},{"first_name":"Xiaohui","last_name":"Fan","full_name":"Fan, Xiaohui"},{"first_name":"Daniel","full_name":"Eisenstein, Daniel","last_name":"Eisenstein"},{"first_name":"Donald P.","last_name":"Schneider","full_name":"Schneider, Donald P."},{"first_name":"Neta A.","full_name":"Bahcall, Neta A.","last_name":"Bahcall"},{"first_name":"J.","full_name":"Brinkmann, J.","last_name":"Brinkmann"},{"full_name":"Fukugita, Masataka","last_name":"Fukugita","first_name":"Masataka"}],"title":"A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. II. Constraints on the 4.0 < z < 5.4 quasar population","quality_controlled":"1","scopus_import":"1","publication_identifier":{"issn":["0004-6256","1538-3881"]},"publisher":"American Astronomical Society","extern":"1","_id":"17727","date_created":"2024-09-06T09:13:53Z","page":"49-54"},{"article_type":"original","author":[{"full_name":"Richards, Gordon T.","last_name":"Richards","first_name":"Gordon T."},{"last_name":"Strauss","full_name":"Strauss, Michael A.","first_name":"Michael A."},{"full_name":"Pindor, Bartosz","last_name":"Pindor","first_name":"Bartosz"},{"first_name":"Zoltán","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","last_name":"Haiman","full_name":"Haiman, Zoltán"},{"first_name":"Xiaohui","last_name":"Fan","full_name":"Fan, Xiaohui"},{"last_name":"Eisenstein","full_name":"Eisenstein, Daniel","first_name":"Daniel"},{"last_name":"Schneider","full_name":"Schneider, Donald P.","first_name":"Donald P."},{"full_name":"Bahcall, Neta A.","last_name":"Bahcall","first_name":"Neta A."},{"last_name":"Brinkmann","full_name":"Brinkmann, J.","first_name":"J."},{"first_name":"Robert","full_name":"Brunner, Robert","last_name":"Brunner"}],"title":"A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z >5.7 sample","quality_controlled":"1","scopus_import":"1","publication_identifier":{"issn":["0004-6256","1538-3881"]},"publisher":"American Astronomical Society","extern":"1","date_created":"2024-09-06T10:22:30Z","_id":"17790","page":"1305-1312","intvolume":"       127","oa":1,"language":[{"iso":"eng"}],"year":"2004","day":"01","volume":127,"publication":"The Astronomical Journal","type":"journal_article","oa_version":"Published Version","abstract":[{"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.","lang":"eng"}],"month":"03","doi":"10.1086/381906","status":"public","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1086/381906"}],"citation":{"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 &#62;5.7 sample. The Astronomical Journal. 127(3), 1305–1312.","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 &#62;5.7 Sample.” <i>The Astronomical Journal</i>. American Astronomical Society, 2004. <a href=\"https://doi.org/10.1086/381906\">https://doi.org/10.1086/381906</a>.","ama":"Richards GT, Strauss MA, Pindor B, et al. A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z &#62;5.7 sample. <i>The Astronomical Journal</i>. 2004;127(3):1305-1312. doi:<a href=\"https://doi.org/10.1086/381906\">10.1086/381906</a>","ieee":"G. T. Richards <i>et al.</i>, “A snapshot survey for gravitational lenses among z ≥ 4.0 quasars. I. The z &#62;5.7 sample,” <i>The Astronomical Journal</i>, vol. 127, no. 3. American Astronomical Society, pp. 1305–1312, 2004.","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.","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 &#62;5.7 sample. <i>The Astronomical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/381906\">https://doi.org/10.1086/381906</a>","mla":"Richards, Gordon T., et al. “A Snapshot Survey for Gravitational Lenses among z ≥ 4.0 Quasars. I. The z &#62;5.7 Sample.” <i>The Astronomical Journal</i>, vol. 127, no. 3, American Astronomical Society, 2004, pp. 1305–12, doi:<a href=\"https://doi.org/10.1086/381906\">10.1086/381906</a>."},"date_published":"2004-03-01T00:00:00Z","article_processing_charge":"No","publication_status":"published","issue":"3","fulldoi":"https://doi.org/10.1086/381906","date_updated":"2024-09-30T13:53:57Z","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345"},{"language":[{"iso":"eng"}],"year":"2003","intvolume":"       125","oa":1,"publication":"The Astronomical Journal","volume":125,"day":"01","scopus_import":"1","publication_identifier":{"issn":["0004-6256","1538-3881"]},"publisher":"American Astronomical Society","article_type":"original","author":[{"first_name":"Xiaohui","full_name":"Fan, Xiaohui","last_name":"Fan"},{"first_name":"Michael A.","last_name":"Strauss","full_name":"Strauss, Michael A."},{"first_name":"Donald P.","full_name":"Schneider, Donald P.","last_name":"Schneider"},{"last_name":"Becker","full_name":"Becker, Robert H.","first_name":"Robert H."},{"first_name":"Richard L.","last_name":"White","full_name":"White, Richard L."},{"first_name":"Zoltán","last_name":"Haiman","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","full_name":"Haiman, Zoltán"},{"full_name":"Gregg, Michael","last_name":"Gregg","first_name":"Michael"},{"last_name":"Pentericci","full_name":"Pentericci, Laura","first_name":"Laura"},{"full_name":"Grebel, Eva K.","last_name":"Grebel","first_name":"Eva K."},{"full_name":"Narayanan, Vijay K.","last_name":"Narayanan","first_name":"Vijay K."},{"first_name":"Yeong-Shang","full_name":"Loh, Yeong-Shang","last_name":"Loh"},{"first_name":"Gordon T.","full_name":"Richards, Gordon T.","last_name":"Richards"},{"full_name":"Gunn, James E.","last_name":"Gunn","first_name":"James E."},{"first_name":"Robert H.","full_name":"Lupton, Robert H.","last_name":"Lupton"},{"last_name":"Knapp","full_name":"Knapp, Gillian R.","first_name":"Gillian R."},{"first_name":"Željko","full_name":"Ivezić, Željko","last_name":"Ivezić"},{"full_name":"Brandt, W. N.","last_name":"Brandt","first_name":"W. N."},{"first_name":"Matthew","full_name":"Collinge, Matthew","last_name":"Collinge"},{"first_name":"Lei","full_name":"Hao, Lei","last_name":"Hao"},{"full_name":"Harbeck, Daniel","last_name":"Harbeck","first_name":"Daniel"},{"last_name":"Prada","full_name":"Prada, Francisco","first_name":"Francisco"},{"last_name":"Schaye","full_name":"Schaye, Joop","first_name":"Joop"},{"full_name":"Strateva, Iskra","last_name":"Strateva","first_name":"Iskra"},{"first_name":"Nadia","full_name":"Zakamska, Nadia","last_name":"Zakamska"},{"first_name":"Scott","last_name":"Anderson","full_name":"Anderson, Scott"},{"first_name":"Jon","last_name":"Brinkmann","full_name":"Brinkmann, Jon"},{"first_name":"Neta A.","last_name":"Bahcall","full_name":"Bahcall, Neta A."},{"first_name":"Don Q.","full_name":"Lamb, Don Q.","last_name":"Lamb"},{"last_name":"Okamura","full_name":"Okamura, Sadanori","first_name":"Sadanori"},{"first_name":"Alex","last_name":"Szalay","full_name":"Szalay, Alex"},{"first_name":"Donald G.","full_name":"York, Donald G.","last_name":"York"}],"title":"A survey of z > 5.7 quasars in the Sloan Digital Sky Survey. II. Discovery of three additional quasars at z > 6","quality_controlled":"1","extern":"1","_id":"17750","date_created":"2024-09-06T09:38:08Z","page":"1649-1659","article_processing_charge":"No","issue":"4","publication_status":"published","fulldoi":"https://doi.org/10.1086/368246","date_updated":"2024-09-30T07:33:02Z","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","abstract":[{"lang":"eng","text":"We present the discovery of three new quasars at z>6 in 1300 deg^2 of SDSS imaging data, J114816.64+525150.3 (z=6.43), J104845.05+463718.3 (z=6.23) and J163033.90+401209.6 (z=6.05). The first two objects have weak Ly alpha emission lines; their redshifts are determined from the positions of the Lyman break. They are only accurate to 0.05 and could be affected by the presence of broad absorption line systems. The last object has a Ly alpha strength more typical of lower redshift quasars. Based on a sample of six quasars at z>5.7 that cover 2870 deg^2 presented in this paper and in Paper I, we estimate the comoving density of luminous quasars at z 6 and M_{1450} < -26.8 to be (8 +/- 3)x10^{-10} Mpc^{-3} (for H_0 = 50 km/s/Mpc, Omega = 1). HST imaging of two z>5.7 quasars and high-resolution ground-based images (seeing 0.4'') of three additional z>5.7 quasars show that none of them is gravitationally lensed. The luminosity distribution of the high-redshfit quasar sample suggests the bright end slope of the quasar luminosity function at z 6 is shallower than Psi L^{-3.5} (2-sigma), consistent with the absence of strongly lensed objects."}],"month":"04","type":"journal_article","oa_version":"Published Version","citation":{"mla":"Fan, Xiaohui, et al. “A Survey of z &#62; 5.7 Quasars in the Sloan Digital Sky Survey. II. Discovery of Three Additional Quasars at z &#62; 6.” <i>The Astronomical Journal</i>, vol. 125, no. 4, American Astronomical Society, 2003, pp. 1649–59, doi:<a href=\"https://doi.org/10.1086/368246\">10.1086/368246</a>.","apa":"Fan, X., Strauss, M. A., Schneider, D. P., Becker, R. H., White, R. L., Haiman, Z., … York, D. G. (2003). A survey of z &#62; 5.7 quasars in the Sloan Digital Sky Survey. II. Discovery of three additional quasars at z &#62; 6. <i>The Astronomical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/368246\">https://doi.org/10.1086/368246</a>","ama":"Fan X, Strauss MA, Schneider DP, et al. A survey of z &#62; 5.7 quasars in the Sloan Digital Sky Survey. II. Discovery of three additional quasars at z &#62; 6. <i>The Astronomical Journal</i>. 2003;125(4):1649-1659. doi:<a href=\"https://doi.org/10.1086/368246\">10.1086/368246</a>","chicago":"Fan, Xiaohui, Michael A. Strauss, Donald P. Schneider, Robert H. Becker, Richard L. White, Zoltán Haiman, Michael Gregg, et al. “A Survey of z &#62; 5.7 Quasars in the Sloan Digital Sky Survey. II. Discovery of Three Additional Quasars at z &#62; 6.” <i>The Astronomical Journal</i>. American Astronomical Society, 2003. <a href=\"https://doi.org/10.1086/368246\">https://doi.org/10.1086/368246</a>.","ista":"Fan X, Strauss MA, Schneider DP, Becker RH, White RL, Haiman Z, Gregg M, Pentericci L, Grebel EK, Narayanan VK, Loh Y-S, Richards GT, Gunn JE, Lupton RH, Knapp GR, Ivezić Ž, Brandt WN, Collinge M, Hao L, Harbeck D, Prada F, Schaye J, Strateva I, Zakamska N, Anderson S, Brinkmann J, Bahcall NA, Lamb DQ, Okamura S, Szalay A, York DG. 2003. A survey of z &#62; 5.7 quasars in the Sloan Digital Sky Survey. II. Discovery of three additional quasars at z &#62; 6. The Astronomical Journal. 125(4), 1649–1659.","ieee":"X. Fan <i>et al.</i>, “A survey of z &#62; 5.7 quasars in the Sloan Digital Sky Survey. II. Discovery of three additional quasars at z &#62; 6,” <i>The Astronomical Journal</i>, vol. 125, no. 4. American Astronomical Society, pp. 1649–1659, 2003.","short":"X. Fan, M.A. Strauss, D.P. Schneider, R.H. Becker, R.L. White, Z. Haiman, M. Gregg, L. Pentericci, E.K. Grebel, V.K. Narayanan, Y.-S. Loh, G.T. Richards, J.E. Gunn, R.H. Lupton, G.R. Knapp, Ž. Ivezić, W.N. Brandt, M. Collinge, L. Hao, D. Harbeck, F. Prada, J. Schaye, I. Strateva, N. Zakamska, S. Anderson, J. Brinkmann, N.A. Bahcall, D.Q. Lamb, S. Okamura, A. Szalay, D.G. York, The Astronomical Journal 125 (2003) 1649–1659."},"date_published":"2003-04-01T00:00:00Z","doi":"10.1086/368246","status":"public","main_file_link":[{"url":"https://doi.org/10.1086/368246","open_access":"1"}]}]