J/ApJ/699/603 Evolution of Swift/BAT blazars (Ajello+, 2009)
The evolution of Swift/BAT blazars and the origin of the MeV background.
Ajello M., Costamante L., Sambruna R.M., Gehrels N., Chiang J., Rau A.,
Escala A., Greiner J., Tueller J., Wall J.V., Mushotzky R.F.
<Astrophys. J., 699, 603-625 (2009)>
=2009ApJ...699..603A 2009ApJ...699..603A
ADC_Keywords: BL Lac objects ; QSOs ; X-ray sources ; Surveys ;
Active gal. nuclei
Keywords: cosmology: observations - diffuse radiation - galaxies: active -
galaxies: jets - surveys - X-rays: diffuse background
Abstract:
We use three years of data from the Swift/Burst Alert Telescope (BAT)
survey to select a complete sample of X-ray blazars above 15keV. This
sample comprises 26 flat-spectrum radio quasars (FSRQs) and 12 BL
Lacertae (BL Lac) objects detected over a redshift range of
0.03<z<4.0. We use this sample to determine, for the first time in the
15-55keV band, the evolution of blazars. We find that, contrary to
the Seyfert-like active galactic nuclei (AGNs) detected by BAT, the
population of blazars shows strong positive evolution. This evolution
is comparable to the evolution of luminous optical quasi-stellar
objects (QSOs) and luminous X-ray-selected AGNs. We also find evidence
for an epoch dependence of the evolution as determined previously for
radio-quiet AGNs. We interpret both these findings as a strong link
between accretion and jet activity. In our sample, the FSRQs evolve
strongly, while our best fit shows that BL Lac objects might not
evolve at all. The blazar population accounts for 10%-20% (depending
on the evolution of the BL Lac objects) of the cosmic X-ray background
(CXB) in the 15-55keV band. We find that FSRQs can explain the entire
CXB emission for energies above 500 keV solving the mystery of the
generation of the MeV background. The evolution of luminous FSRQs
shows a peak in redshift (zc=4.3±0.5) which is larger than the
one observed in QSOs and X-ray-selected AGNs. We argue that FSRQs can
be used as tracers of massive elliptical galaxies in the early
universe.
Description:
For the analysis presented here, we used Swift/BAT survey observations
performed between 2005 March and 2008 March. Data screening and
processing was performed according to the recipes presented in Ajello
et al. (2008, Cat. J/ApJ/678/102). The chosen energy interval is 15-55keV.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 109 38 Blazars sample (X-ray blazars above 15keV)
table5.dat 93 205 Sample of 199 Seyferts and 6 radio galaxies
detected by BAT
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See also:
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
IX/32 : ROSAT Bright Survey (Fischer+, 1998-2000)
J/A+A/510/A48 : Palermo Swift-BAT Hard X-ray Catalogue (Cusumano+, 2010)
J/A+A/524/A64 : The 54-month Palermo BAT-survey catalogue (Cusumano+, 2010)
J/ApJS/186/378 : Hard X-ray survey from Swift-BAT 2004-2006 (Tueller+, 2010)
J/ApJS/183/46 : Fermi/LAT bright gamma-ray source list (0FGL) (Abdo+, 2009)
J/A+A/495/691 : Multifrequency catalogue of blazars, Roma-BZCAT (Massaro+,
2009)
J/ApJ/681/113 : Swift BAT survey of AGNs (Tueller+, 2008)
J/ApJ/678/102 : BAT X-ray survey. I. (Ajello+, 2008)
J/ApJS/175/97 : CGRaBS: survey of γ-ray blazar candidates (Healey+,
2008)
J/ApJ/633/L77 : SWIFT/BAT detections of AGN (Markwardt+, 2005)
J/ApJS/123/79 : Third EGRET catalog (3EG) (Hartman+, 1999)
J/A+AS/131/303 : GHz-Peaked-Spectrum radio sources (Stanghellini+ 1998)
Byte-by-byte Description of file: table[25].dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- SWIFT SWIFT name (JHHMM.m+DDMM)
14- 20 F7.3 deg RAdeg Right ascension in decimal degrees (J2000)
22- 28 F7.3 deg DEdeg Declination in decimal degrees (J2000)
30- 34 F5.2 aW/m2 Flux Flux in the 15-55keV energy band
(in 10-15erg/cm2/s)
36- 39 F4.2 aW/m2 e_Flux Flux uncertainty
41- 45 F5.1 --- S/N Signal to noise ratio
47- 72 A26 --- OName Simbad other name (1)
74- 84 A11 --- OType Object type (2)
86- 91 F6.4 --- z Redshift
93 A1 --- BAT? [y ] y for detected by the BAT 22 month
survey (only for table 5) (3)
95- 98 F4.2 --- Gamma ? X-ray photon index (only for table 2)
100-103 F4.2 --- e_Gamma ? Photon index uncertainty (only for table 2)
105 A1 --- 3EG? [y ] (only for table 2) (4)
107 A1 --- LAT? [y ] (only for table 2) (5)
109 A1 --- Ref Reference (only for table 2) (6)
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Note (1): Sources with a SWIFT name, in table 5, were identified in the works
of Tueller et al. (2008, Cat. J/ApJ/681/113; 2010, Cat. J/ApJS/186/378).
Note that 2 names were corrected at CDS compared to the published table:
* in table 2, PKS 2335+093 corrected into PKS 2325+093
* in table 5, SDSS J0759.87+232448.3 corrected into SDSS J075959.87+232448.2;
and SWIFT J2141.0+1603 has been removed.
Note (2): Classes are:
FSRQ = flat-spectrum radio quasar
BLLAC = BL Lacertae objects with high-frequency (HBL) or low-frequency (LBL)
peaked;
RG = radio galaxies
GALAXY = candidate radio-quiet AGNs which are of the XBONG type (see
Tueller et al. 2010, Cat. J/ApJS/186/378) or for which an optical
spectrum is not yet available.
Seyfert, Sy = Seyfert galaxies with type (1 to 2)
Note (3): Is the source detected in the 22 months BAT survey of Tueller et al.
(2010, Cat. J/ApJS/186/378) where energy band was 15-195keV with an
exposure of 22 months versus 36 months for this survey.
Note (4): y for counterpart in the third EGRET catalog (Hartman et al. 1999,
Cat. J/ApJS/123/79; <3EG JHHMM+DDMM> in Simbad)
Note (5): y for detected by Fermi-LAT (Abdo 2009, Cat. J/ApJS/183/46;
<0FGL JHHMM.m+DDMM> in Simbad)
Note (6): References for the optical classification and redshift as follows:
B = Massaro et al. (2009, Cat. J/A+A/495/691),
F = Falomo et al. (1994ApJS...93..125F 1994ApJS...93..125F),
C = Healey et al. (2008, Cat. J/ApJS/175/97),
I = Masetti et al. (2006A&A...455...11M 2006A&A...455...11M),
K = Stickel et al. (1993, Cat. III/75),
M = Marcha et al. (1996MNRAS.281..425M 1996MNRAS.281..425M),
R = Schwope et al. (2000, Cat. IX/32),
S = Sbarufatti et al. (2005ApJ...635..173S 2005ApJ...635..173S),
T = Stanghellini et al. (1998, Cat. J/A+AS/131/303),
V = Veron-Cetty & Veron (2006, Cat. VII/248, superseded by Cat. VII/258).
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 28-Jun-2011