J/ApJ/882/181 Hyper-luminous X-ray sources from SDSS and CSC2 (Barrows+, 2019)
A catalog of hyper-luminous X-ray sources and intermediate-mass black hole
candidates out to high redshifts.
Barrows R.S., Mezcua M., Comerford J.M.
<Astrophys. J., 882, 181 (2019)>
=2019ApJ...882..181B 2019ApJ...882..181B
ADC_Keywords: X-ray sources; Active gal. nuclei; Galaxies, optical
Keywords: Active galactic nuclei ; AGN host galaxies ; Dwarf galaxies ;
Galaxy mergers ; Intermediate-mass black holes ;
X-ray active galactic nuclei ; X-ray quasars
Abstract:
Hyper-luminous X-ray sources (HLXs; LX>1041erg/s) are off-nuclear
X-ray sources in galaxies and strong candidates for intermediate-mass
black holes (IMBHs). We have constructed a sample of 169 HLX
candidates by combining X-ray detections from the Chandra Source
Catalog (Version 2) with galaxies from the Sloan Digital Sky Survey
and registering individual images for improved relative astrometric
accuracy. The spatial resolution of Chandra allows for the sample to
extend out to z∼0.9. Optical counterparts are detected among
one-fourth of the sample, one-third of which are consistent with dwarf
galaxy stellar masses. The average intrinsic X-ray spectral slope
indicates efficient accretion, potentially driven by galaxy mergers,
and the column densities suggest one-third of the sample has
significant X-ray absorption. We find that 144 of the HLX candidates
have X-ray emission that is significantly in excess of the expected
contribution from star formation and hot gas, strongly suggesting that
they are produced by accretion onto black holes more massive than
stars. After correcting for an average background or foreground
contamination rate of 8%, we estimate that at least ∼20 of the HLX
candidates are consistent with IMBH masses, and this estimate is
potentially several times higher assuming more efficient accretion.
This catalog currently represents the largest sample of uniformly
selected, off-nuclear IMBH candidates. These sources may represent
scenarios in which a low-mass galaxy hosting an IMBH has merged with a
more massive galaxy and provide an excellent sample for testing models
of low-mass BH formation and merger-driven growth.
Description:
Our initial galaxy sample is drawn from the catalog of SDSS detections
that are classified as galaxies and with photometric redshifts
derived by the SDSS pipeline. We use the galaxy photometric redshift
catalog from Data Release 7 (DR7; Abazajian+ 2009, II/294), but also
include any additional galaxies detected in subsequent data releases
through DR14 (Abolfathi+ 2018ApJS..235...42A 2018ApJS..235...42A).
We use the Chandra Source Catalog Version 2 (Evans+, 2019, IX/57)
Master Source Catalog as our parent sample of X-ray sources detected
at >3σ significance.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 169 Astrometric properties of the HLX candidates
table2.dat 154 169 X-ray properties of the HLX candidates
table3.dat 100 169 Galaxy properties and multi-wavelength detections
of the HLX candidates
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
VII/158 : Revised and Updated Catalog of Quasi-stellar Objects (Hewitt+ 1993)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
IX/57 : The Chandra Source Catalog (CSC), Release 2.0 (Evans+, 2019)
J/ApJS/154/519 : Properties of ultraluminous X-ray candidates (Swartz+, 2004)
J/AJ/130/873 : Properties of BQS objects in the SDSS DR3 area (Jester+, 2005)
J/ApJS/157/59 : Ultraluminous X-ray sources in nearby galaxies (Liu+, 2005)
J/A+A/429/1125 : Catalog of Ultraluminous X-ray sources (Liu+, 2005)
J/ApJ/670/92 : New sample of low-mass black holes in AGN (Greene+, 2007)
J/ApJ/741/49 : ULX candidates in nearby galaxies (Swartz+, 2011)
J/MNRAS/416/1844 : 2XMM ultraluminous X-ray source candidates (Walton+, 2011)
J/ApJS/201/30 : The Chandra COSMOS survey. III. (Civano+, 2012)
J/ApJ/756/27 : Classification of sources from the 2XMMi-DR3 cat. (Lin+, 2012)
J/MNRAS/419/2095 : HMXBs in nearby galaxies (Mineo+, 2012)
J/ApJ/772/26 : AGN with WISE. II. The NDWFS Bootes field (Assef+, 2013)
J/ApJ/775/116 : z<0.06 active BH galaxies from SDSS-DR8 (Reines+, 2013)
J/ApJ/813/82 : z<0.06 broad-line AGN emission-line measures (Reines+, 2015)
J/ApJ/807/129 : X-ray to MIR luminosities relation of AGNs (Stern, 2015)
J/ApJ/819/62 : The COSMOS-Legacy Survey (CLS) catalog (Civano+, 2016)
J/ApJS/222/12 : Luminous X-ray candidates within D25 of galaxies (Gong+, 2016)
J/ApJ/825/7 : Evolution of ∼6Ms CDF-S galaxies (Lehmer+, 2016)
J/ApJS/234/23 : The WISE AGN candidates catalogs (Assef+, 2018)
J/MNRAS/479/807 : Catalogue of faint local radio AGN (Lofthouse+, 2018)
J/MNRAS/483/5554 : Non-nuclear X-ray sources in nearby gal. (Earnshaw+, 2019)
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/169] Internal index number
5- 8 F4.2 --- z [0.05/0.87] Host galaxy redshift
10- 13 A4 --- --- [SDSS]
15- 33 A19 --- SDSS Host galaxy identifier (JHHMMSS.ss+DDMMSS.s)
35- 38 A4 --- --- [2CXO]
40- 55 A16 --- 2CXO HLX candidate identifier (JHHMMSS.s+DDMMSS)
from the Chandra Source Catalog DR2 (IX/57)
57- 60 F4.1 --- Navg [0/14] Average number of matches (1)
62- 65 F4.1 arcsec AngSep [0.8/12.2] HLX candidate angular offset
from the host galaxy center
67- 69 F3.1 arcsec e_AngSep [0.1/2] Uncertainty in AngSep
71- 74 F4.1 kpc PhySep [2.5/75.1] HLX candidate projected physical
offset from the host galaxy center
76- 78 F3.1 kpc e_PhySep [0.2/8.8] Uncertainty in PhySep
80- 84 F5.1 deg PA [2/359.2] HLX candidate offset position angle;
East of North
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Note (1): Between the SDSS r-band image and all Chandra OBSID(s) in
which the HLX candidate is detected.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/169] Internal index number
5- 8 F4.2 --- sigma [0.4/5.3] 1σ PSF size at HLX position
10- 15 F6.2 10+34W LXS [0/585] Soft (0.5-2keV) band luminosity
in units of 1041erg/s (2)
17- 22 F6.2 10+34W e_LXS [0/318] Lower uncertainty in LXS
24- 29 F6.2 10+34W E_LXS [0/658] Upper uncertainty in LXS
31- 36 F6.2 10+35W LXH [0.1/214] Hard (2-10keV) band luminosity
in units of 1042erg/s (2)
38- 43 F6.2 10+35W e_LXH [0.01/102] Lower uncertainty in LXH
45- 50 F6.2 10+35W E_LXH [0.01/623] Upper uncertainty in LXH
52- 57 F6.2 10+35W LXF [0.14/238] Full (0.5-10keV) band luminosity
in units of 1042erg/s (2)
59- 64 F6.2 10+35W e_LXF [0.01/108] Lower uncertainty in LXF
66- 71 F6.2 10+35W E_LXF [0.01/644.3] Upper uncertainty in LXF
73- 76 F4.2 --- Gamma [0.53/2.82] Intrinsic photon index
78 A1 --- f_Gamma [a] a=fixed value; see section 2.4.1
80- 83 F4.2 --- e_Gamma [0/1.1]? Lower uncertainty in Gamma
85- 88 F4.2 --- E_Gamma [0.1/1.1]? Upper uncertainty in Gamma
90- 94 F5.2 10+22/cm2 nH [0/25.1] Intrinsic column density
96 A1 --- f_nH [a] a=fixed value; see section 2.4.1
98-101 F4.2 10+22/cm2 e_nH [0/4]? Lower uncertainty in nH
103-106 F4.2 10+22/cm2 E_nH [0/5.1]? Upper uncertainty in nH
108-112 F5.1 ct Scts [1.5/331] Soft (0.5-2keV) band photon counts
114-117 F4.1 ct e_Scts [1.5/19] Lower uncertainty in Scts
119-122 F4.1 ct E_Scts [0.2/18] Upper uncertainty in Scts
124-128 F5.1 ct Hcts [9.4/515] Hard (2-10keV) band photon counts
130-133 F4.1 ct e_Hcts [3.6/25] Lower uncertainty in Hcts
135-138 F4.1 ct E_Hcts [2.3/21] Upper uncertainty in Hcts
140-144 F5.2 --- HR [-0.54/0.96] Hardness ratio (HR=(H-S)/(H+S))
146-149 F4.2 --- e_HR [0.01/0.23] Lower uncertainty in HR
151-154 F4.2 --- E_HR [0.02/0.22] Upper uncertainty in HR
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Note (2): Unabsorbed and rest-frame luminosities.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/169] Internal index identifier
5- 8 F4.1 % fc [0.2/86.3] Contamination rate
10- 13 F4.1 % fcind [0.2/36.4] LG06 contamination rate
15- 18 F4.1 [Msun] logM*H [7.3/15.6] log host galaxy stellar mass
20- 23 F4.1 [Msun] e_logM*H [5/13.6] Uncertainty in logM*H
25- 28 F4.1 [Msun] logM*HLX [7/13]? log HLX stellar counter part mass
30- 33 F4.1 [Msun] e_logM*HLX [5.9/11.6]? Uncertainty in logM*HLX
35- 39 F5.2 [-] log(X/V) [-3.1/1] log X-ray to optical flux ratio
41 A1 --- f_log(X/V) [a] a = lower limit on log(X/V);
see Section 3.3.2
43- 51 F9.2 10+32W LXXRB [0.02/395880] Hard (2-10keV) luminosity
from XRBs in units of 1039erg/s
53- 61 F9.2 10+32W e_LXXRB [0.01/215540] Lower uncertainty in LXXRB
63- 71 F9.2 10+32W E_LXXRB [0.03/470490] Upper uncertainty in LXXRB
73- 79 F7.2 10+30W LXISM [0.01/9800] Hard (2-10keV) luminosity from
hot ISM gas in units of 1037erg/s
81- 87 F7.2 10+30W e_LXISM [0.01/5320] Lower uncertainty in LXISM
89- 96 F8.2 10+30W E_LXISM [0.01/11640] Upper uncertainty in LXISM
98-100 A3 --- MIR-AGN HLX candidate is a detected MIR AGN?
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 15-Feb-2021