The evolution of QSOs derived from soft X-ray surveys

被引:48
作者
Page, MJ
Mason, KO
McHardy, IM
Jones, LR
Carrera, FJ
机构
[1] UNIV SOUTHAMPTON, DEPT PHYS, SOUTHAMPTON SO17 1BJ, HANTS, ENGLAND
[2] NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA
[3] UNIV CANTABRIA, CSIC, INST FIS CANTABRIA, E-39005 SANTANDER, SPAIN
关键词
surveys; galaxies: active; quasars: general; cosmology: observations; X-rays: galaxies;
D O I
10.1093/mnras/291.2.324
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present a study of the evolution of active galactic nuclei (AGN) selected in Einstein and ROSAT surveys. A total of 748 broad-line AGN are included in the study, including 29 with z > 2. Pure luminosity evolution provides a good description of the evolution for q(0) = 0. For q(0) = 0.5 we find that pure luminosity evolution underpredicts the number of intermediate-redshift (1.4 < z < 2), low-luminosity AGN. Evolution models with strong evolution at high redshift (z > 1.8) are rejected at high confidence levels. Models with no evolution or negative evolution at z >, 1.8 are acceptable. [V-e/V-a] tests, which are model-independent, suggest that at z > 1.8 evolution is negative, i.e., QSO space densities and/or luminosities decline with redshift. Our model luminosity functions predict that broad-line AGN with z < 4 contribute less than 45 per cent of the 1-2 keV X-ray background. We derive a simple expression to correct a two-power-law luminosity function for the spurious evolution caused by the dispersion of X-ray spectral slopes. When the dispersion in AGN spectral slopes is taken into account, we find that the redshift at which evolution stops may be as low as z similar to 1.4 for both q(0) = 0 and q(0) = 0.5.
引用
收藏
页码:324 / 336
页数:13
相关论文
共 31 条
[1]   SIMULTANEOUS ANALYSIS OF SEVERAL COMPLETE SAMPLES - V-VMAX AND VE-VA VARIABLES, WITH APPLICATIONS TO QUASARS [J].
AVNI, Y ;
BAHCALL, JN .
ASTROPHYSICAL JOURNAL, 1980, 235 (03) :694-716
[2]   DEEP X-RAY SOURCE COUNTS FROM A FLUCTUATION ANALYSIS OF ROSAT PSPC IMAGES [J].
BARCONS, X ;
BRANDUARDIRAYMONT, G ;
WARWICK, RS ;
FABIAN, AC ;
MASON, KO ;
MCHARDY, I ;
ROWANROBINSON, M .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1994, 268 (04) :833-840
[3]   THE EVOLUTION OF OPTICALLY SELECTED QSOS .2. [J].
BOYLE, BJ ;
SHANKS, T ;
PETERSON, BA .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1988, 235 (04) :935-948
[4]   A DEEP ROSAT SURVEY .1. THE QSO X-RAY LUMINOSITY FUNCTION [J].
BOYLE, BJ ;
GRIFFITHS, RE ;
SHANKS, T ;
STEWART, GC ;
GEORGANTOPOULOS, I .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1993, 260 (01) :49-58
[5]   A DEEP ROSAT SURVEY .4. THE EVOLUTION OF X-RAY-SELECTED QSOS [J].
BOYLE, BJ ;
SHANKS, T ;
GEORGANTOPOULOS, I ;
STEWART, GC ;
GRIFFITHS, RE .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1994, 271 (03) :639-648
[6]   THE CAMBRIDGE-CAMBRIDGE ROSAT SERENDIPITY SURVEY .1. X-RAY-LUMINOUS GALAXIES [J].
BOYLE, BJ ;
MCMAHON, RG ;
WILKES, BJ ;
ELVIS, M .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1995, 272 (02) :462-468
[7]   THE UK DEEP AND MEDIUM SURVEYS WITH ROSAT - LOG-N-LOG-S RELATION [J].
BRANDUARDIRAYMONT, G ;
MASON, KO ;
WARWICK, RS ;
CARRERA, FJ ;
GRAFFAGNINO, VG ;
MITTAZ, JPD ;
PUCHNAREWICZ, EM ;
SMITH, PJ ;
BARBER, CR ;
POUNDS, KA ;
STEWART, GC ;
MCHARDY, IM ;
JONES, LR ;
MERRIFIELD, MR ;
FABIAN, AC ;
MCMAHON, RG ;
WARD, MJ ;
GEORGE, IM ;
JONES, MH ;
LAWRENCE, A ;
ROWANROBINSON, M .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1994, 270 (04) :947-957
[8]  
CASH W, 1979, ASTROPHYS J, V228, P939, DOI 10.1086/156922
[9]   ASCA and ROSAT observations of the QSF3 field: The x-ray background in the 0.1-7 keV band [J].
Chen, LW ;
Fabian, AC ;
Gendreau, KC .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1997, 285 (03) :449-471
[10]   The Cambridge-Cambridge ROSAT serendipity survey .4. The X-ray properties [J].
Ciliegi, P ;
Elvis, M ;
Wilkes, BJ ;
Boyle, BJ ;
McMahon, RG .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1997, 284 (02) :401-415