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Title: Clustering of quasars in SDSS-IV eBOSS: study of potential systematics and bias determination

Abstract

We study the first year of the eBOSS quasar sample in the redshift range 0.9< z <2.2 which includes 68,772 homogeneously selected quasars. We show that the main source of systematics in the evaluation of the correlation function arises from inhomogeneities in the quasar target selection, particularly related to the extinction and depth of the imaging data used for targeting. We propose a weighting scheme that mitigates these systematics. We measure the quasar correlation function and provide the most accurate measurement to date of the quasar bias in this redshift range, b {sub Q} = 2.45 ± 0.05 at z-bar =1.55, together with its evolution with redshift. We use this information to determine the minimum mass of the halo hosting the quasars and the characteristic halo mass, which we find to be both independent of redshift within statistical error. Using a recently-measured quasar-luminosity-function we also determine the quasar duty cycle. The size of this first year sample is insufficient to detect any luminosity dependence to quasar clustering and this issue should be further studied with the final ∼500,000 eBOSS quasar sample.

Authors:
; ; ; ;  [1]; ;  [2];  [3];  [4];  [5];  [6]; ;  [7];  [8];  [9];  [10];  [11];  [12];  [13];
  1. IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)
  2. Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States)
  3. Lawrence Berkeley National Lab, 1 Cyclotron Rd, Berkeley CA 94720 (United States)
  4. Center for Cosmology and AstroParticle Physics, The Ohio State University, Columbus, OH 43210 (United States)
  5. Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, 10003 (United States)
  6. School of Physics and Astronomy, North Haugh, St. Andrews KY16 9SS (United Kingdom)
  7. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)
  8. Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States)
  9. Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße, 85748 Garching (Germany)
  10. Laboratoire d'Astrophysique, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland)
  11. Steward Observatory, University of Arizona, Tucson, AZ 85721–0065 (United States)
  12. Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama building, PO1 3FX, Portsmouth (United Kingdom)
  13. Instituto de Fìsica Teórica (IFT) UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain)
Publication Date:
OSTI Identifier:
22676111
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 07; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRELATION FUNCTIONS; CORRELATIONS; ERRORS; EVALUATION; LUMINOSITY; MASS; QUASARS; RED SHIFT; STAR CLUSTERS

Citation Formats

Laurent, Pierre, Goff, Jean-Marc Le, Burtin, Etienne, Bourboux, Hélion du Mas des, Palanque-Delabrouille, Nathalie, Eftekharzadeh, Sarah, Myers, Adam, White, Martin, Ross, Ashley J., Tinker, Jeremy, Tojeiro, Rita, Bautista, Julian, Dawson, Kyle, Brinkmann, Jonathan, Comparat, Johan, Kneib, Jean-Paul, McGreer, Ian D., Percival, Will J., Prada, Francisco, E-mail: jmlegoff@cea.fr, and and others. Clustering of quasars in SDSS-IV eBOSS: study of potential systematics and bias determination. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/07/017.
Laurent, Pierre, Goff, Jean-Marc Le, Burtin, Etienne, Bourboux, Hélion du Mas des, Palanque-Delabrouille, Nathalie, Eftekharzadeh, Sarah, Myers, Adam, White, Martin, Ross, Ashley J., Tinker, Jeremy, Tojeiro, Rita, Bautista, Julian, Dawson, Kyle, Brinkmann, Jonathan, Comparat, Johan, Kneib, Jean-Paul, McGreer, Ian D., Percival, Will J., Prada, Francisco, E-mail: jmlegoff@cea.fr, & and others. Clustering of quasars in SDSS-IV eBOSS: study of potential systematics and bias determination. United States. doi:10.1088/1475-7516/2017/07/017.
Laurent, Pierre, Goff, Jean-Marc Le, Burtin, Etienne, Bourboux, Hélion du Mas des, Palanque-Delabrouille, Nathalie, Eftekharzadeh, Sarah, Myers, Adam, White, Martin, Ross, Ashley J., Tinker, Jeremy, Tojeiro, Rita, Bautista, Julian, Dawson, Kyle, Brinkmann, Jonathan, Comparat, Johan, Kneib, Jean-Paul, McGreer, Ian D., Percival, Will J., Prada, Francisco, E-mail: jmlegoff@cea.fr, and and others. Sat . "Clustering of quasars in SDSS-IV eBOSS: study of potential systematics and bias determination". United States. doi:10.1088/1475-7516/2017/07/017.
@article{osti_22676111,
title = {Clustering of quasars in SDSS-IV eBOSS: study of potential systematics and bias determination},
author = {Laurent, Pierre and Goff, Jean-Marc Le and Burtin, Etienne and Bourboux, Hélion du Mas des and Palanque-Delabrouille, Nathalie and Eftekharzadeh, Sarah and Myers, Adam and White, Martin and Ross, Ashley J. and Tinker, Jeremy and Tojeiro, Rita and Bautista, Julian and Dawson, Kyle and Brinkmann, Jonathan and Comparat, Johan and Kneib, Jean-Paul and McGreer, Ian D. and Percival, Will J. and Prada, Francisco, E-mail: jmlegoff@cea.fr and and others},
abstractNote = {We study the first year of the eBOSS quasar sample in the redshift range 0.9< z <2.2 which includes 68,772 homogeneously selected quasars. We show that the main source of systematics in the evaluation of the correlation function arises from inhomogeneities in the quasar target selection, particularly related to the extinction and depth of the imaging data used for targeting. We propose a weighting scheme that mitigates these systematics. We measure the quasar correlation function and provide the most accurate measurement to date of the quasar bias in this redshift range, b {sub Q} = 2.45 ± 0.05 at z-bar =1.55, together with its evolution with redshift. We use this information to determine the minimum mass of the halo hosting the quasars and the characteristic halo mass, which we find to be both independent of redshift within statistical error. Using a recently-measured quasar-luminosity-function we also determine the quasar duty cycle. The size of this first year sample is insufficient to detect any luminosity dependence to quasar clustering and this issue should be further studied with the final ∼500,000 eBOSS quasar sample.},
doi = {10.1088/1475-7516/2017/07/017},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 07,
volume = 2017,
place = {United States},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}
  • The Sloan Digital Sky Survey IV extended Baryonic Oscillation Spectroscopic Survey (SDSS-IV/eBOSS) will observe 195,000 emission-line galaxies (ELGs) to measure the Baryonic Acoustic Oscillation standard ruler (BAO) at redshift 0.9. To test different ELG selection algorithms, 9,000 spectra were observed with the SDSS spectrograph as a pilot survey based on data from several imaging surveys. First, using visual inspection and redshift quality flags, we show that the automated spectroscopic redshifts assigned by the pipeline meet the quality requirements for a reliable BAO measurement. We also show the correlations between sky emission, signal-to-noise ratio in the emission lines, and redshift error.more » Then we provide a detailed description of each target selection algorithm we tested and compare them with the requirements of the eBOSS experiment. As a result, we provide reliable redshift distributions for the different target selection schemes we tested. Lastly, we determine an target selection algorithms that is best suited to be applied on DECam photometry because they fulfill the eBOSS survey efficiency requirements.« less
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    Cited by 4