The Chandra cosmos legacy survey: clustering of X-ray-selected AGNs at 2.9 ≤ z ≤ 5.5 using photometric redshift probability distribution functions

Journal Article · Sun Nov 20 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/832/1/70· OSTI ID:22868450

Allevato, V.; Finoguenov, A. ^[1]; Civano, F.; Marchesi, S.; Cappelluti, N. ^[2]; Shankar, F. ^[3]; Zamorani, G. ^[4]; Hasinger, G.; Suh, H. ^[5]; Salvato, M. ^[6]; Miyaji, T. ^[7]; Gilli, R.; Brusa, M.; Lanzuisi, G.; Vignali, C. ^[8]; Trakhtenbrot, B.; Schawinski, K. ^[9]; Griffiths, R. ^[10]; Karim, A. ^[11]

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1. Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki (Finland)
2. Yale Center for Astronomy and Astrophysics, 260 Whitney Avenue, New Haven, CT 06520 (United States)
3. Department of Physics and Astronomy, University of Southampton, Highfield, SO17 1BJ (United Kingdom)
4. INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy)
5. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
6. Max-Planck-Institute für Extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany)
7. Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Ensenada (Mexico)
8. Dipartimento di Fisica e Astronomia, Alma Mater Studiorum, Universit di Bologna, viale Berti Pichat 6/2, I-40127, Bologna (Italy)
9. Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland)
10. University of Hawaii at Hilo, 200 W.Kawili St., Hilo, HI 96720 (United States)
11. Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany)

We present the measurement of the projected and redshift-space two-point correlation function (2pcf) of the new catalog of Chandra COSMOS-Legacy active galactic nucleus (AGN) at 2.9 ≤ z ≤ 5.5 (〈L{sub bol}〉 ∼ 10{sup 46} erg s{sup −1}) using the generalized clustering estimator based on phot-z probability distribution functions in addition to any available spec-z. We model the projected 2pcf, estimated using π {sub max} = 200 h{sup −1} Mpc with the two-halo term and we derive a bias at z ∼ 3.4 equal to b = 6.6{sub −0.55}{sup +0.60}, which corresponds to a typical mass of the hosting halos of log M {sub h} = 12.83{sub −0.11}{sup +0.12} h{sup −1} M {sub ⊙}. A similar bias is derived using the redshift-space 2pcf, modeled including the typical phot-z error σ {sub z} = 0.052 of our sample at z ≥ 2.9. Once we integrate the projected 2pcf up to π {sub max} = 200 h{sup −1} Mpc, the bias of XMM and Chandra COSMOS at z = 2.8 used in Allevato et al. is consistent with our results at higher redshifts. The results suggest only a slight increase of the bias factor of COSMOS AGNs at z ≳ 3 with the typical hosting halo mass of moderate-luminosity AGNs almost constant with redshift and equal to log M {sub h} = 12.92{sub −0.18}{sup +0.13} at z = 2.8 and log M {sub h} = 12.83{sub −0.11}{sup +0.12} at z ∼ 3.4, respectively. The observed redshift evolution of the bias of COSMOS AGNs implies that moderate-luminosity AGNs still inhabit group-sized halos at z ≳ 3, but slightly less massive than observed in different independent studies using X-ray AGNs at z ≤ 2.

• OSTI ID: 22868450
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 832; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CATALOGS
CORRELATION FUNCTIONS
DISTRIBUTION FUNCTIONS
GALAXIES
LUMINOSITY
MASS
NONLUMINOUS MATTER
PROBABILITY
RED SHIFT
SPACE
UNIVERSE
X RADIATION