J/A+A/681/A16 Chandra, XMM-Newton and Swift-XRT ULX and HLX (Tranin+ 2024)
Statistical study of a large and cleaned sample of ultraluminous and
hyperluminous X-ray sources.
Tranin H., Webb N., Godet O., Quintin E.
<Astron. Astrophys. 681, A16 (2024)>
=2024A&A...681A..16T 2024A&A...681A..16T (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Binaries, X-ray ; X-ray sources
Keywords: black hole physics - X-rays: galaxies - X-rays: binaries -
methods: observational - accretion, accretion disks
Abstract:
Ultraluminous and hyperluminous X-ray (ULX and HLX) sources could
constitute interesting laboratories to further improve our
understanding of the supermassive black hole growth through
super-Eddington accretion episodes and successive mergers of lighter
holes. ULXs are thought to be powered by super-Eddington accretion
onto stellar-mass compact objects, while HLXs are of an unknown
nature, but they could be good candidates for accreting intermediate
mass black holes (IMBHs). However, a significant portion of the sample
of ULX and HLX candidates derived from catalogue searches are in fact
background active galactic nuclei (AGN).
Here we build samples of ULXs and HLXs from the three largest X-ray
catalogues available, compiled from XMM-Newton, Swift-XRT, and Chandra
detections, and the GLADE catalogue containing 1.7 million galaxies at
D<1000Mpc. We aim to characterise the frequency, environment,
hardness, and variability of ULXs and HLXs to better assess their
differences and understand their populations.
After a thorough classification of these X-ray sources, we were able
to remove ∼42% of sources with a signal-to-noise ratio (S/N)>3
which were shown to be contaminants, to obtain the cleanest sample of
ULXs and HLXs to date. From a sample of 1342 ULXs and 191 HLXs
detected with a S/N>3σ, we study the occupation fraction,
hardness, variability, radial distribution, and preferred environment
of the sources. We built their Malmquist-corrected X-ray luminosity
functions (XLFs) and compared them with previous studies. Thanks to
the unprecedented size of the sample, we were able to statistically
compare ULXs and HLXs and assess the differences in their nature. The
interpretation of HLXs as IMBHs is investigated.
A significant break is seen in the XLF at ∼1040erg/s. With our
ULX sample, containing ≲2% of contaminants, we are able to confirm
that ULXs are located preferentially in spiral galaxies and galaxies
with higher star formation rates. While X-ray binaries (XRBs), ULXs,
and most HLXs share common hardness and variability distributions, a
fraction of HLXs appear significantly softer. Unlike ULXs, HLXs seem
to reside equally in spiral as well as lenticular and elliptical
galaxies. We note that 35% of the HLX candidates have an optical
counterpart, and we estimate the mass of 120 of them to be in the
range of 2x103-105M☉. Most of the HLX population
is found to be consistent with an accreting massive black hole in a
dwarf galaxy satellite of the primary host. This diverse nature needs
to be confirmed with deeper optical and infrared observations, as well
as upcoming X-ray facilities.
Description:
The recent versions of large X-ray catalogues 2SXPS, 4XMM-DR11 and
CSC2.0 are cross-correlated with the largely complete galaxy catalogue
GLADE to obtain these samples of ULXs and HLXs. An automatic
classification of X-ray sources (Tranin et al., 2022A&A...657A.138T 2022A&A...657A.138T,
Cat. J/A+A/657/A138) is used to drastically reduce the fraction of
contaminants among selected ULXs, as well as a visual inspection of
optical counterparts. HLX contaminants are selected out by removing
background and foreground objects, according to the (spectroscopic or
photometric) redshift of their optical counterpart, if any.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 378 234 List of HLX candidates obtained in this study
tablea2.dat 294 2192 List of ULX candidates obtained in this study
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See also:
VII/237 : HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
VII/281 : GLADE v2.3 catalog (Dalya+, 2018)
VII/291 : GLADE+ (Galaxy List for the Advanced Detector Era) (Dalya+, 2022)
IX/45 : The Chandra Source Catalog, Release 1.1 (Evans+ 2012)
IX/57 : The Chandra Source Catalog (CSC), Release 2.0 (Evans+, 2019)
IX/58 : 2SXPS Swift X-ray telescope point source catalogue (Evans+, 2020)
IX/59 : XMM-Newton Serendipitous Source Catalogue 4XMM-DR9 (Webb+, 2020)
IX/63 : XMM-Newton Serendipitous Source Catalogue 4XMM-DR10 (Webb+, 2022)
IX/65 : XMM-Newton Serendipitous Source Catalogue 4XMM-DR11 (Webb+, 2022)
IX/68 : XMM-Newton Serendipitous Source Catalogue 4XMM-DR12 (Webb+, 2023)
J/A+A/657/A138 : Classification of Swift and XMM-Newton sources (Tranin+, 2022)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- MASTERID Unique identifier in the compiled ULX catalog
6- 27 A22 --- IAUNAME Name of the source
29 I1 --- CSC2 [0/1] Source taken from the CSC2 catalog
31 I1 --- 4XMM [0/1] Source taken from the 4XMMDR11 catalog
33 I1 --- 2SXPS [0/1] Source taken from the 2SXPS catalog
35- 43 F9.5 deg RAdeg Right Ascension (J2000)
45- 53 F9.5 deg DEdeg Declination (J2000)
55- 59 F5.3 arcsec Err63 1-sigma position error radius
61- 69 E9.3 mW/m2 Flux Average source flux in broad band (G1)
71- 79 E9.3 mW/m2 e_Flux Error on average source flux in broad band
81- 85 F5.1 --- SNR Signal-to-noise ratio
87- 95 E9.3 10-7W LX Average X-ray luminosity in broad band
97-102 F6.3 --- HRms ? Medium to soft hardness ratio (G2)
104-109 F6.3 --- HRhm ? Hard to medium hardness ratio (G2)
111-114 F4.2 [-] fratio ? log. max-to-min flux ratio between multi-
instrument detections of the source
116-120 F5.2 [-] frcons ? log. (max-err)-to-(min+err) flux ratio
122-130 F9.5 deg RAodeg ? Right ascension of the optical counterpart
132-140 F9.5 deg DEodeg ? Declination of the optical counterpart
142-146 F5.3 arcsec SepOpt ? Separation of the optical counterpart
148-152 F5.2 mag Bmag ? B magnitude of the optical counterpart
154-158 F5.2 mag Rmag ? R magnitude of the optical counterpart
160-164 F5.3 --- pCtpOpt ? Probability of the optical counterpart
166-170 F5.3 --- pAnyOpt ? Probability to have any optical counterpart
172-180 A9 --- RefOpt ? Reference of the optical counterpart
182-188 I7 --- PGC ? Principal Galaxy Catalog number of the host
190-198 F9.5 deg RAgdeg Right Ascension (J2000) of the host
200-208 F9.5 deg DEgdeg Declination (J2000) of the host
210-213 F4.1 arcsec R1 Semi-major axis of D25 ellipse of the host
215-218 F4.1 arcsec R2 Semi-minor axis of D25 ellipse of the host
220-224 F5.1 deg PA Position angle of D25 ellipse of the host
226-231 F6.1 Mpc Dist Luminosity distance of the host
233-236 A4 --- type ? Simbad morphological type of the host
238-241 F4.1 --- t ? HyperLEDA Hubble type of the host
243-245 F3.1 --- et ? HyperLEDA error on Hubble type of the host
247 I1 --- spiral [0/1]? Goddard & Shamir (2020ApJS..251...28G 2020ApJS..251...28G)
host is spiral (from ML on PanSTARRS image)
249 I1 --- ellipt [0/1]? Goddard & Shamir (2020ApJS..251...28G 2020ApJS..251...28G)
host is elliptical
(from ML on PanSTARRS image)
251-255 F5.2 Msun Mstar ? Stellar mass of the host in GLADE+
257-261 F5.2 Msun e_Mstar ? Error on stellar mass of the host in GLADE+
263-268 F6.3 [Msun/yr] logSFR ? log. of the star-formation rate from W3
magnitude (Cluver et al.,
2017ApJ...850...68C 2017ApJ...850...68C)
270-274 F5.3 --- GalSep Galactocentric distance from the host center
(0: source is at the center, 1: is on edge)
276-279 F4.1 kpc Sepkpc Physical separation to the primary host
center
281-288 E8.2 Msun MBH ? Black hole mass if Lbol=0.24LEdd=LX*10
290-297 E8.2 Msun Mstar2 ? Stellar mass of the secondary host (if any)
299-309 A11 --- HLXclass Category of the HLX candidate
311-312 I2 --- class ? Label of the source (G3)
314 I1 --- classif [0/2]? Best classification of the source
(0: AGN, 1: soft source, 2: XRB)
316-321 F6.3 --- outlier ? Outlier measure of the classification
323-330 F8.6 --- PbaC0 ? Probability of the AGN class
332-339 F8.6 --- PbaC1 ? Probability of the soft source class
341-348 F8.6 --- PbaC2 ? Probability of the XRB class
350-358 E9.3 mW/m2 F39 Minimum flux of a ULX candidate in the host
(i.e. giving LX=1e39erg/s)
360-367 F8.6 --- Ncont Number of background contaminant expected to
overlap the area of the host
(Moretti et al., 2003ApJ...588..696M 2003ApJ...588..696M)
369 I1 --- NULX ? Number of initial ULX candidate in the host
(from the same X-ray catalog)
371-378 F8.6 --- Pbacont ? Probability of the source to be a ULX
contaminant
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- MASTERID Unique identifier in the compiled ULX catalog
7- 28 A22 --- IAUNAME Name of the source
30 I1 --- CSC2 [0/1] Source taken from the CSC2 catalog
32 I1 --- 4XMM [0/1] Source taken from the 4XMMDR11 catalog
34 I1 --- 2SXPS [0/1] Source taken from the 2SXPS catalog
36- 44 F9.5 deg RAdeg Right Ascension (J2000)
46- 54 F9.5 deg DEdeg Declination (J2000)
56- 60 F5.3 arcsec Err63 1-sigma position error radius
62- 70 E9.3 mW/m2 Flux Average source flux in broad band (G1)
72- 80 E9.3 mW/m2 e_Flux Error on average source flux in broad band
82- 86 F5.1 --- SNR Signal-to-noise ratio
88- 96 E9.3 10-7W LX Average X-ray luminosity in broad band
98-103 F6.3 --- HRms ? Medium to soft hardness ratio (G2)
105-110 F6.3 --- HRhm ? Hard to medium hardness ratio (G2)
112-115 F4.2 [-] fratio ? log. max-to-min flux ratio between multi-
instrument detections of the source
117-121 F5.2 [-] frcons ? log. (max-err)-to-(min+err) flux ratio
between multi-instrument detections
123-129 I7 --- PGC ? Principal Galaxy Catalog number of the host
131-139 F9.5 deg RAgdeg Right Ascension (J2000) of the host
141-149 F9.5 deg DEgdeg Declination (J2000) of the host
151-155 F5.1 arcsec R1 Semi-major axis of D25 ellipse of the host
157-161 F5.1 arcsec R2 Semi-minor axis of D25 ellipse of the host
163-167 F5.1 deg PA Position angle of D25 ellipse of the host
169-173 F5.1 Mpc Dist Luminosity distance of the host
175-178 A4 --- type ? Simbad morphological type of the host
180-183 F4.1 --- t ? HyperLEDA Hubble type of the host
185-187 F3.1 --- et ? HyperLEDA error on Hubble type of the host
189 I1 --- spiral ? (Goddard&Shamir2020) host is spiral
(from ML on PanSTARRS image)
191 I1 --- ellipt ? (Goddard&Shamir2020) host is elliptical
(from ML on PanSTARRS image)
193-201 F9.5 Msun Mstar ? Stellar mass of the host in GLADE+
203-210 F8.5 Msun e_Mstar ? Error on stellar mass of the host in GLADE+
212-217 F6.3 [Msun/yr] logSFR ? log. of the star-formation rate from W3
magnitude (Cluver et al.,
2017ApJ...850...68C 2017ApJ...850...68C)
219-223 F5.3 --- GalSep Galactocentric distance from the host center
(0: source is at the center, 1: is on edge)
225-226 I2 --- class ? Label of the source (G3)
228 I1 --- classif [0/2]? Best classification of the source
(0: AGN, 1: soft source, 2: XRB)
230-235 F6.3 --- outlier ? Outlier measure of the classification
237-244 F8.6 --- PbaC0 ? Probability of the AGN class
246-253 F8.6 --- PbaC1 ? Probability of the soft source class
255-262 F8.6 --- PbaC2 ? Probability of the XRB class
264-272 E9.3 mW/m2 F39 ? Minimum flux of a ULX candidate in the host
(i.e. giving LX=1e39erg/s)
274-281 F8.6 --- Ncont ? Number of background contaminant expected
to overlap the area of the host
(Moretti et al., 2003ApJ...588..696M 2003ApJ...588..696M)
283-284 I2 --- NULX Number of initial ULX candidate in the host
(from the same X-ray catalog)
286-294 F9.6 --- Pbacont ? Probability of the source to be a ULX
contaminant
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Global notes:
Note (G1): Broad band energy range in keV:
CSC2 0.5 - 7 (ACIS)
0.1 - 10 (HRC)
4XMM 0.2 - 12
2SXPS 0.3 - 10
For CSC2, flux is the fixed powlaw flux if available, or the aperture
flux if positive, or the average aperture flux.
Note (G2): Energy bands in keV:
Hard band: CSC2 2 - 7
4XMM 2 - 4.5
2SXPS 2 - 10
Medium band: CSC2 1.2 - 2
4XMM 1 - 2
2SXPS 1 - 2
Soft band: CSC2 0.5 - 1.2
4XMM 0.5 - 1
2SXPS 0.3 - 1
Note (G3): Label of the source as follows:
0 = known AGN
1 = known soft source (include stars, SNe, SNR)
2 = known XRB
99 = not in training sample
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Acknowledgements:
Hugo Tranin, htranin(at)icc.ub.edu
(End) Hugo Tranin [ICCUB, Univ. Barcelona], Patricia Vannier [CDS] 22-Jun-2023