J/ApJ/739/57 Ultra hard X-ray AGNs in the Swift/BAT survey (Koss+, 2011)
Host galaxy properties of the Swift BAT ultra hard X-ray selected active
galactic nucleus.
Koss M., Mushotzky R., Veilleux S., Winter L.M., Baumgartner W.,
Tueller J., Gehrels N., Valencic L.
<Astrophys. J., 739, 57 (2011)>
=2011ApJ...739...57K 2011ApJ...739...57K
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Redshifts ; Morphology ;
Photometry, SDSS
Keywords: galaxies: active - galaxies: interactions - X-rays: galaxies
Abstract:
We have assembled the largest sample of ultra hard X-ray selected
(14-195keV) active galactic nucleus (AGN) with host galaxy optical
data to date, with 185 nearby (z<0.05), moderate luminosity AGNs from
the Swift BAT sample. The BAT AGN host galaxies have intermediate
optical colors (u-r and g-r) that are bluer than a comparison sample
of inactive galaxies and optically selected AGNs from the Sloan
Digital Sky Survey (SDSS) which are chosen to have the same stellar
mass. Based on morphological classifications from the RC3 and the
Galaxy Zoo, the bluer colors of BAT AGNs are mainly due to a higher
fraction of mergers and massive spirals than in the comparison
samples. BAT AGNs in massive galaxies (logM*>10.5) have a 5-10 times
higher rate of spiral morphologies than in SDSS AGNs or inactive
galaxies. We also see enhanced far-infrared emission in BAT AGN
suggestive of higher levels of star formation compared to the
comparison samples. BAT AGNs are preferentially found in the most
massive host galaxies with high concentration indexes indicative of
large bulge-to-disk ratios and large supermassive black holes. The
narrow-line (NL) BAT AGNs have similar intrinsic luminosities as the
SDSS NL Seyferts based on measurements of [OIII]5007. There is also a
correlation between the stellar mass and X-ray emission. The BAT AGNs
in mergers have bluer colors and greater ultra hard X-ray emission
compared to the BAT sample as a whole.
Description:
The BAT survey is an all-sky survey in the ultra hard X-ray range that
has identified 461 objects of which 262 are AGNs (Tueller et al. 2010,
Cat. J/ApJS/186/378). We restrict the sample to nearby AGN (z<0.05)
which includes 80% of the BAT sample. These AGNs can be further
classified on the basis of broad or narrow emission lines. We define
NL AGN as having Hα<2000km/s using spectroscopic data from
Winter et al. (2010ApJ...710..503W 2010ApJ...710..503W), Ho et al. (1997ApJS..112..391H 1997ApJS..112..391H),
and the SDSS. For those BAT galaxies without spectra, we use the SDSS
galaxy class separator or available data from NED to separate NL and
broad-line objects.
This survey covers 125 nearby AGNs or 50% of the entire BAT AGN sample
from the 22 month survey (Cat. J/ApJS/186/378). We also included an
additional 60 AGN galaxies detected in the 58 month BAT sample catalog
(Baumgartner et al. 2010, submitted). The optical imaging data for
these galaxies include 17 nights at the Kitt Peak 2.1m telescope in
the ugriz SDSS bands (Table 1) and data from the SDSS (Table 2). The
final Kitt Peak and SDSS sample includes a total of 185 galaxies, 79
BAT AGN host galaxies observed at Kitt Peak, 92 from the SDSS, and 14
galaxies observed by both the SDSS and at Kitt Peak.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 66 82 Summary of Kitt Peak observations
table2.dat 67 121 Summary of SDSS observations
table4.dat 82 179 Summary of photometry and derived properties
table6.dat 46 159 Summary of morphological properties
--------------------------------------------------------------------------------
See also:
J/ApJS/201/34 : Swift-INTEGRAL X-ray (SIX) survey (Bottacini+, 2012)
J/ApJ/728/58 : Swift-BAT survey of AGNs (Burlon+, 2011)
J/ApJS/195/2 : The second Swift BAT GRB catalog (BAT2) (Sakamoto+, 2011)
J/A+A/525/A127 : Properties of X-ray selected AGNs (Tasse+, 2011)
J/ApJS/186/378 : 22 month Swift-BAT hard X-ray survey (Tueller+, 2010)
J/A+A/524/A64 : The 54-month Palermo BAT-survey catalogue (Cusumano+, 2010)
J/A+A/510/A48 : Palermo Swift-BAT Hard X-ray Catalogue (Cusumano+, 2010)
J/A+A/520/A47 : Blazars in the Swift-BAT hard X-ray sky (Maselli+, 2010)
J/ApJ/699/603 : Evolution of Swift/BAT blazars (Ajello+, 2009)
J/ApJ/692/758 : BAL QSOs in SDSS-DR5 (Gibson+, 2009)
J/ApJ/681/113 : Swift BAT survey of AGNs (Tueller+, 2008)
J/ApJ/678/102 : BAT X-ray survey. I. (Ajello+, 2008)
J/ApJ/633/L77 : SWIFT/BAT detections of AGN (Markwardt+, 2005)
J/A+A/434/475 : Redshifts for X-ray selected AGNs (Kitsionas+, 2005)
Byte-by-byte Description of file: table[12].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Source name
25- 34 A10 "YYYY/MM/DD" Date Date of the observation
36- 40 A5 --- Type Source type (1)
42- 46 F5.3 --- z [0.001/0.051] Redshift
48- 52 F5.1 Mpc Dist [4.1/222.8] Distance (2)
54- 57 F4.2 mag E(B-V) [0.01/1.65] The (B-V) color excess (3)
59- 62 F4.2 --- Air Median Airmass of all 5 filter observations
64- 67 F4.2 arcsec PSF [0.8/2.5] Gaussian FWHM of r band image
--------------------------------------------------------------------------------
Note (1): AGN type and host galaxy type from Tueller et al. 2008,
Cat. J/ApJ/681/113. For AGN types, optical identifications are listed,
where available. Where G is indicated, there are no optical emission
lines indicative of the presence of an AGN and the optical spectrum
looks like a galaxy spectrum.
Note (2): We used the mean of the redshift independent distance from NED when
available. Otherwise, we adopted the following cosmological
parameters to determine distances: Ωm=0.27,
ΩΛ=0.73, and H0=71km/s/Mpc.
Note (3): Milky Way reddening values, E(B-V), from IRAS and COBE/DIRBE.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Galaxy name
26- 30 F5.2 mag umag ? SDSS u band magnitude (1)
32- 36 F5.2 mag gmag SDSS g band magnitude (1)
38- 42 F5.2 mag rmag SDSS r band magnitude (1)
44- 49 F6.3 mag imag SDSS i band magnitude (1)
51- 56 F6.3 mag zmag [7.875/18.35] SDSS z band magnitude (1)
58- 62 F5.2 [Msun] logM [8.28/11.09] Log of stellar masses (2)
64- 68 F5.2 % PSr [0/99] Percentage of AGN (3)
70- 73 F4.2 mag E(g-r) ? Estimated (g-r) dust reddening correction (4)
75- 78 F4.2 mag E(g-r)i ? Estimated (g-r) inclination reddening
correction (5)
80 A1 --- uc [Y ] u band contamination? (6)
82 A1 --- c [Y ] griz' band contamination? (7)
--------------------------------------------------------------------------------
Note (1): Measured host galaxy Petrosian mag after subtraction of AGN
contamination using GALFIT.
Note (2): We used the software KCORRECT Blanton et al (2007AJ....133..734B 2007AJ....133..734B) with
the ugriz photometry to calculate the stellar masses. This code uses
the stellar population models of Bruzual et al. (2003MNRAS.344.1000B 2003MNRAS.344.1000B)
and photoionization models of Kewley et al. (2001,
Cat. J/ApJS/132/37).
Note (3): To total (AGN and galaxy) light in the r band.
Note (4): For dust based on AGN host ugriz SED fitting using FAST
Kriek et al. (2009ApJ...700..221K 2009ApJ...700..221K) with single-burst stellar
population models.
Note (5): For spiral galaxies based on inclination following
Masters et al. (2010MNRAS.404..792M 2010MNRAS.404..792M).
Note (6): We excluded the u photometry from this study because of the
possibility of AGN contamination even after subtraction with GALFIT
since %PSr>20.
Note (7): We excluded the griz photometry and determination of M* from this
study because of the possibility of AGN contamination even after
subtraction with GALFIT.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Galaxy name
25- 30 F6.2 arcsec Rp [1.36/216]? Petrosian radius (1)
32- 35 F4.2 --- C [1.7/3.94]? Concentration index (2)
37- 39 A3 --- Class Galaxy Zoo class (3)
41- 44 F4.2 --- b/a [0.13/0.98] Observed axial ratio (4)
46 A1 --- Broad [Y ] Broad-line AGN? (5)
--------------------------------------------------------------------------------
Note (1): The Petrosian radius was determined following the SDSS see
http://www.sdss.org/dr7/algorithms/photometry.html. Blank values
indicate that the Petrosian radius and concentration failed to
converge. This happened more often for close mergers or in a
broad-line AGN where the AGN was imperfectly subtracted.
Note (2): The concentration index is defined as the ratio of the radii
containing 90 and 50 per cent of the Petrosian r-band galaxy light.
Blank values indicate that the Petrosian radius and concentration
failed to converge. This happened more often for close mergers or
in a broad-line AGN where the AGN was imperfectly subtracted.
Note (3): Where E stands for ellipticals, I, for intermediates, S, for spirals,
and M for mergers/peculiars. For the Kitt Peak data, which has no
Galaxy Zoo data, we use the Hubble Types from the RC3 with T=-6
to -4 corresponding to ellipticals, T=-3 to 0 to intermediates,
T>0 to spirals.
Note (4): We use b/a as a proxy for inclination. An b/a=1 corresponds to a
face-on galaxy. We use the g band and fit to the
25th mag/arcsecond2 isophote.
Note (5): Whether the galaxy has a broad-line AGN based on SDSS galaxy class
or the available optical spectra. While we excluded these broad-line
measurements from the morphological analysis, we have provided them
for completeness. We subtracted the AGN model for these galaxies
before determining the Petrosian radius and concentration index.
However, the difficulty of perfectly subtracting the AGN light
distribution makes these values more uncertain.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Jan-2013