J/ApJS/248/31 HST & Chandra obs. of elliptical galaxies (Lehmer+, 2020)
X-ray binary luminosity function scaling relations in elliptical galaxies:
evidence for globular cluster seeding of low-mass X-ray binaries in Galactic
fields.
Lehmer B.D., Ferrell A.P., Doore K., Eufrasio R.T., Monson E.B.,
Alexander D.M., Basu-Zych A., Brandt W.N., Sivakoff G.R., Tzanavaris P.,
Yukita M., Fragos T., Ptak A.
<Astrophys. J. Suppl. Ser., 248, 31 (2020)>
=2020ApJS..248...31L 2020ApJS..248...31L
ADC_Keywords: Galaxies, nearby; Clusters, globular; Binaries, X-ray;
Photometry, HST; Photometry, SDSS; Ultraviolet;
Photometry, infrared; X-ray sources
Keywords: Elliptical galaxies ; Early-type galaxies ; X-ray binary stars ;
Low-mass x-ray binary stars ; Globular star clusters ;
X-ray point sources
Abstract:
We investigate X-ray binary (XRB) luminosity function (XLF) scaling
relations for Chandra-detected populations of low-mass XRBs (LMXBs)
within the footprints of 24 early-type galaxies. Our sample includes
Chandra and Hubble Space Telescope observed galaxies at D≲25Mpc that
have estimates of the globular cluster (GC) specific frequency (SN)
reported in the literature. As such, we are able to directly classify
X-ray-detected sources as being coincident with unrelated
background/foreground objects, GCs, or sources that are within the
fields of the galaxy targets. We model the GC and field LMXB
population XLFs for all galaxies separately and then construct global
models characterizing how the LMXB XLFs vary with galaxy stellar mass
and SN. We find that our field LMXB XLF models require a component
that scales with SN and has a shape consistent with that found for
the GC LMXB XLF. We take this to indicate that GCs are "seeding" the
galactic field LMXB population, through the ejection of GC LMXBs
and/or the diffusion of the GCs in the galactic fields themselves.
However, we also find that an important LMXB XLF component is required
for all galaxies that scales with stellar mass, implying that a
substantial population of LMXBs are formed "in situ," which dominates
the LMXB population emission for galaxies with SN≲2. For the first
time, we provide a framework quantifying how directly associated GC
LMXBs, GC-seeded LMXBs, and in situ LMXBs contribute to LMXB XLFs in
the broader early-type galaxy population.
Description:
We chose to make use of the Harris+ (2013, J/ApJ/772/82) catalog of
422 galaxies with published measurements of globular cluster (GC)
population properties. See Section 2 for further explanations.
The FUV to FIR SEDs for the selected 24 galaxies were extracted using
publicly available data from GALEX, Swift, HST, SDSS, 2MASS, WISE,
Spitzer, and Herschel. See Section 3.1 for further details.
By selection, our galaxies have HST ACS coverage in both "blue" and
"red" filters (defined below) and cover the bulk of the stellar mass
within the Ks-band ellipses of the galaxies. For 21 of the galaxies,
we used the F475W (g475) and F850LP (z850) bandpasses as our blue
and red filters, respectively; however, when this combination was not
available, we utilized F475W and F814W (z814) (NGC1404 and NGC4382)
or F606W (r606) and F814W (NGC3923) filter pairs.
Observations were made between 2004 September and 2012 October;
see Table 3.
We made use of Chandra ACIS-S and ACIS-I data sets that had aim points
within 5' of the central coordinates of the galaxy (given in Table 1).
The observation logs for all galaxies are presented in Table 5. In
total 113 unique ObsIDs were used for the 24 galaxies in our sample,
representing 5.5Ms of Chandra observation time. Observations span
2003 May to 2008 March.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 99 24 Nearby galaxy sample and properties
table2.dat 895 24 Multi-wavelength coverage used in SED fitting
table3.dat 50 67 HST Advanced Camera for Surveys (ACS)
observation log
table4.dat 53 24 HST source classifications and SN,loc estimates
table5.dat 81 133 Chandra Advanced CCD Imaging Spectrometer (ACIS)
observation log
table6.dat 135 24 Field X-ray luminosity function fits by galaxy
table7.dat 60 24 Summary of field X-ray luminosity function fits
by Galaxy
tableb1.dat 88 3923 X-ray point-source catalog and properties
--------------------------------------------------------------------------------
See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
B/hst : HST Archived Exposures Catalog (STScI, 2007)
B/swift : Swift Master Catalog (HEASARC, 2004-)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
II/328 : AllWISE Data Release (Cutri+ 2013)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
II/335 : Revised cat. of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
J/MNRAS/330/547 : Local galaxy ages and metallicities (Terlevich+, 2002)
J/ApJ/602/231 : Chandra X-ray point sources in nearby gal. (Colbert+, 2004)
J/ApJ/621/673 : Line indices for 124 early-type galaxies (Thomas+, 2005)
J/ApJS/169/401 : ChaMP X-ray point source catalog (Kim+, 2007)
J/ApJ/662/525 : LMXBs in globular clusters of 5 galaxies (Kundu+, 2007)
J/A+A/469/807 : Catalogue of Galactic low-mass X-ray binaries (Liu+, 2007)
J/ApJ/689/983 : LMXBs in early-type galaxies. I. Chandra (Humphrey+, 2008)
J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)
J/ApJ/736/90 : Chandra X-ray sources of NGC 1399 (Paolillo+, 2011)
J/A+A/533/A33 : LMXBs detected in nearby galaxies (Zhang+, 2011)
J/ApJ/764/41 : X-ray binary evolution across cosmic time (Fragos+, 2013)
J/ApJ/776/L31 : Energy feedback from XRB from z=0 to z=19.92 (Fragos+, 2013)
J/ApJ/772/82 : A catalog of globular cluster systems (Harris+, 2013)
J/ApJS/204/14 : Deep Chandra observations of NGC 4649. I. (Luo+, 2013)
J/ApJS/220/10 : AEGIS-X Deep survey of EGS (AEGIS-XD) (Nandra+, 2015)
J/AJ/150/81 : CHANG-ES. IV. VLA D-configuration obs. (Wiegert+, 2015)
J/ApJ/799/159 : Globular cluster pop. in S4G galaxies (Zaritsky+, 2015)
J/ApJ/819/62 : The COSMOS-Legacy Survey (CLS) catalog (Civano+, 2016)
J/ApJ/825/7 : Evolution of ∼6Ms CDF-S galaxies (Lehmer+, 2016)
J/ApJ/829/20 : Chandra ACIS survey in nearby galaxies. II (Wang+, 2016)
J/ApJS/224/15 : Improved 2Ms and 250ks Chandra catalogs (Xue+, 2016)
J/ApJ/835/223 : A catalog of nearby galaxies with Chandra obs. (She+, 2017)
J/ApJS/228/2 : Chandra Deep Field-South survey: 7Ms sources (Luo+, 2017)
J/ApJS/236/48 : The Chandra UDS survey (X-UDS) (Kocevski+, 2018)
J/ApJS/243/3 : Chandra observations of SINGS galaxies (Lehmer+, 2019)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 11 A6 --- Messier Alternative Messier designation,
if applicable
13- 16 A4 --- Morph Morphological type (1)
18- 19 I2 h RAh Hour of Right Ascension (J2000) (2)
21- 22 I2 min RAm Minute of Right Ascension (J2000)
24- 27 F4.1 s RAs Second of Right Ascension (J2000)
29- 29 A1 --- DE- Sign of the Declination (J2000) (2)
30- 31 I2 deg DEd Degree of Declination (J2000) (2)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 39 F4.1 arcsec DEs Arcsecond of Declination (J2000)
41- 45 F5.2 Mpc Dist [10/23.4] Adopted distance (median=17.09) (3)
47- 50 F4.2 Mpc e_Dist [0.2/3.2] 1σ error in Dist
52- 55 F4.2 arcmin amaj [0.6/3.1] Size parameter,
semi-major axis length (median=1.88) (4)
57- 60 F4.2 arcmin bmin [0.5/2.5] Size parameter,
semi-minor axis length (median=1.24) (4)
62- 66 F5.1 deg PA [7/170] Size parameter,
positional angle, east from north (4)
68- 72 F5.2 [Msun] logM* [9.7/11.1] log, galactic stellar mass
from SED fitting (median=10.62) (5)
74- 77 F4.2 [Msun] e_logM* [0.01/0.06] 1σ error in logM*
79- 82 F4.2 --- SN [0.5/9.3] GC specific frequency SN
(median=2.34) (6)
84- 87 F4.2 --- e_SN [0.1/1.4] 1σ error in SN
89- 89 A1 --- f_SN Flag on SN (7)
91- 94 F4.2 Gyr tage [4.5/9.1] Stellar-mass-weighted age
(median=8.76) (8)
96- 99 F4.2 Gyr e_tage [0.04/1.1] 1σ error in tage
--------------------------------------------------------------------------------
Note (1): Morphological type as reported in Harris+ (2013, J/ApJ/772/82).
Note (2): Right ascension and declination of the galactic center based on the
2MASS positions derived by Jarrett+ (2003AJ....125..525J 2003AJ....125..525J).
Note (3): For consistency with the Harris+ (2013ApJ...772...82H 2013ApJ...772...82H) GC specific
frequencies, we adopted the distances reported in Harris+
(2013, J/ApJ/772/82); see references within.
Note (4): Ks-band isophotal ellipse parameters, including, respectively,
semi-major axis, a, semi-minor axis, b, and position angle east from
north, PA. The ellipses tract the 20mag/arcsec2 surface brightness
contour of each galaxy (derived by Jarrett+ 2003AJ....125..525J 2003AJ....125..525J)
and are centered on the positions given.
Note (5): Logarithm of the galactic stellar mass, Mstar, determined by our
SED fitting. These stellar masses are based on photometry from the areal
regions defined RAdeg, DEdeg, a, b, PA, excluding a central 3 arcsecond
circular region and any sky coverage that does not have HST exposure
(see Section 3.1 for details). The cumulative stellar mass of the sample
is log(Mtot/Msun)=12.1.
Note (6): Globular cluster specific frequency, SN, as reported by
Harris+ 2013, J/ApJ/772/82 using their tabulated values of Ngc, VMag
and their Equation 4.
Note (7): Flag on SN for NGC 4649 as follows:
a = Value of SN has been corrected from Harris+ 2013, J/ApJ/772/82
following the assumptions in Section 3.2.
Note (8): Stellar-mass-weighted age of the population, based on the SED
fitting techniques applied in Section 3.1.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 18 E13.7 mJy GALEX-FUV [0.06/4.1] GALEX FUV Flux
20- 32 E13.7 mJy e_GALEX-FUV [0.01/0.7] 1-sigma GALEX-FUV uncertainty
34- 46 E13.7 mJy GALEX-NUV [0.5/6.3] GALEX NUV Flux
48- 60 E13.7 mJy e_GALEX-NUV [0.08/1] 1-sigma GALEX-NUV uncertainty
62- 75 E14.7 mJy SWIFT-UVW2 [1.4/4.9]?=-999 Swift/UVOT UVW2 Flux
77- 89 E13.7 mJy e_SWIFT-UVW2 [0.07/0.3]?=0 1-sigma SWIFT-UVW2 uncertainty
91-104 E14.7 mJy SWIFT-UVM2 [1/4.4]?=-999 Swift/UVOT UVM2 Flux
106-118 E13.7 mJy e_SWIFT-UVM2 [0.05/0.3]?=0 1-sigma SWIFT-UVM2 uncertainty
120-133 E14.7 mJy SWIFT-UVW1 [4.4/16.6]?=-999 Swift/UVOT UVW1 Flux
135-147 E13.7 mJy e_SWIFT-UVW1 [0.2/0.9]?=0 1-sigma SWIFT-UVW1 uncertainty
149-162 E14.7 mJy SWIFT-U [18.8/61.7]?=-999 Swift/UVOT U Flux
164-176 E13.7 mJy e_SWIFT-U [0.9/3.1]?=0 1-sigma SWIFT-U uncertainty
178-191 E14.7 mJy SWIFT-B [71/228]?=-999 Swift/UVOT B Flux
193-205 E13.7 mJy e_SWIFT-B [3/12]?=0 1-sigma SWIFT-B uncertainty
207-220 E14.7 mJy SWIFT-V [153/487]?=-999 Swift/UVOT V Flux
222-234 E13.7 mJy e_SWIFT-V [7/25]?=0 1-sigma SWIFT-V uncertainty
236-249 E14.7 mJy SDSS-u [5.4/68.3]?=-999 SDSS u Flux
251-263 E13.7 mJy e_SDSS-u [0.2/3.7]?=0 1-sigma SDSS-u uncertainty
265-278 E14.7 mJy SDSS-g [25/377]?=-999 SDSS g Flux
280-292 E13.7 mJy e_SDSS-g [1/19]?=0 1-sigma SDSS-g uncertainty
294-307 E14.7 mJy SDSS-r [46/767]?=-999 SDSS r Flux
309-321 E13.7 mJy e_SDSS-r [2/39]?=0 1-sigma SDSS-r uncertainty
323-336 E14.7 mJy SDSS-i [68/1171]?=-999 SDSS i Flux
338-350 E13.7 mJy e_SDSS-i [3/59]?=0 1-sigma SDSS-i uncertainty
352-365 E14.7 mJy SDSS-z [86/1515]?=-999 SDSS z Flux
367-379 E13.7 mJy e_SDSS-z [4/76]?=0 1-sigma SDSS-z uncertainty
381-394 E14.7 mJy HST-F475W [23/356]?=-999 HST/ACS F475W Flux
396-408 E13.7 mJy e_HST-F475W [1/18]?=0 1-sigma HST-F475W uncertainty
410-423 E14.7 mJy HST-F606W [203/204]?=-999 HST/ACS F606W Flux
425-437 E13.7 mJy e_HST-F606W [10/10.2]?=0 1-sigma HST-F606W uncertainty
439-452 E14.7 mJy HST-F814W [380/880]?=-999 HST/ACS F814W Flux
454-466 E13.7 mJy e_HST-F814W [19/44]?=0 1-sigma HST-F814W uncertainty
468-481 E14.7 mJy HST-F850LP [84/1501]?=-999 HST/ACS F850LP Flux
483-495 E13.7 mJy e_HST-F850LP [4/76]?=0 1-sigma HST-F850LP uncertainty
497-509 E13.7 mJy 2MASS-J [117/2371]?=-999 2MASS J Flux
511-523 E13.7 mJy e_2MASS-J [11/238]?=0 1-sigma 2MASS-J uncertainty
525-537 E13.7 mJy 2MASS-H [143/2841]?=-999 2MASS H Flux
539-551 E13.7 mJy e_2MASS-H [14/285]?=0 1-sigma 2MASS-H uncertainty
553-565 E13.7 mJy 2MASS-Ks [113/2308]?=-999 2MASS Ks Flux
567-579 E13.7 mJy e_2MASS-Ks [11/231]?=0 1-sigma 2MASS-Ks uncertainty
581-593 E13.7 mJy WISE-W1 [64/1167]?=-999 WISE W1 (3.4um) Flux
595-607 E13.7 mJy e_WISE-W1 [1/28]?=0 1-sigma WISE-W1 uncertainty
609-621 E13.7 mJy WISE-W2 [36/633]?=-999 WISE W2 (4.6um) Flux
623-635 E13.7 mJy e_WISE-W2 [1/18]?=0 1-sigma WISE-W2 uncertainty
637-649 E13.7 mJy WISE-W4 [21/4989]?=-999 WISE W4 (22um) Flux
651-663 E13.7 mJy e_WISE-W4 [1/285]?=0 1-sigma WISE-W4 uncertainty
665-678 E14.7 mJy IRAC-3.6 [108/1103]?=-999 Spitzer/IRAC 3.6um Flux
680-692 E13.7 mJy e_IRAC-3.6 [5/56]?=0 1-sigma IRAC-3.6 uncertainty
694-707 E14.7 mJy IRAC-4.5 [67/640]?=-999 Spitzer/IRAC 4.5um Flux
709-721 E13.7 mJy e_IRAC-4.5 [3/32]?=0 1-sigma IRAC-4.5 uncertainty
723-736 E14.7 mJy IRAC-8.0 [35/434]?=-999 Spitzer/IRAC 8.0um Flux
738-750 E13.7 mJy e_IRAC-8.0 [1/22]?=0 1-sigma IRAC-8.0 uncertainty
752-765 E14.7 mJy MIPS-24 [11/200]?=-999 Spitzer/MIPS 24um Flux
767-779 E13.7 mJy e_MIPS-24 [0.6/11]?=0 1-sigma MIPS-24 uncertainty
781-794 E14.7 mJy PACS-70 ?=-999 Herschel/PACS 70um Flux (always NULL)
796-808 E13.7 mJy e_PACS-70 ?=0 1-sigma PACSR-70 uncertainty
810-823 E14.7 mJy PACS-100 [169/24748]?=-999 Herschel/PACS 100um Flux
825-837 E13.7 mJy e_PACS-100 [20/2505]?=0 1-sigma PACS-100 uncertainty
839-852 E14.7 mJy PACS-160 [46/22639]?=-999 Herschel/PACS 160um Flux
854-866 E13.7 mJy e_PACS-160 [11/2267]?=0 1-sigma PACS-160 uncertainty
868-881 E14.7 mJy SPIRE-250 [19/1291]?=-999 Herschel/SPIRE 250um Flux
883-895 E13.7 mJy e_SPIRE-250 [4/194]?=0 1-sigma SPIRE-250 uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 7 I2 --- Field [1/12] HST Field number
9- 18 A10 "Y/M/D" Obs.date Observation date, UT
20- 24 A5 "h:m" Obs.time Observation time, UT
26- 29 I4 s ExpF475W [676/2204] Exposure time, HST/ACS F475W
31- 34 I4 s ExpF850LP [420/3005]? Exposure time, HST/ACS F850LP
36- 36 I1 --- NF475W [2/4]? Number, line dither pointings,
HST/ACS F475W
38- 38 I1 --- NF850LP [2/4]? Number, line dither pointings,
HST/ACS F850LP
40- 44 F5.3 arcsec SpF475W [0.14/3.1]? Spacing, HST/ACS F475W
46- 50 F5.3 arcsec SpF850LP [0.14/3.1]? Spacing, HST/ACS F850LP
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 9 F4.1 mag Mg50 [-6.5/-4.6]? Effective 50% completeness
limit for the F475W band (g475) (9)
11- 14 I4 --- NbgOpt [46/519] Total number of background sources,
optical (Total_24galaxies=3114)
16- 19 I4 --- NgcOpt [54/1054] Total number of globular clusters,
optical (Total_24galaxies=8112)
21- 25 F5.1 mag VMagloc [-21.3/-18.4] "Local" absolute V-band
magnitude of the host galaxy
27- 30 F4.2 --- SNloc [0.95/5.1] "Local" GC specific frequency
32- 35 F4.2 --- e_SNloc [0.07/0.4] Uncertainty in SNloc
37- 40 I4 --- NtX [4/286] Total number of X-ray detected sources
(Total_24galaxies=1937)
42- 44 I3 --- NbgX [0/22] Number of background X-ray sources
(Total_24galaxies=104)
46- 48 I3 --- NgcX [0/95] Number of GC X-ray sources (Total=595)
50- 53 I4 --- NfX [4/169] Number of field X-ray souces (Total=1238)
--------------------------------------------------------------------------------
Note (9): The effective 50% completeness limit for the F475W band (g475),
appropriate for sources with GC-like light profiles.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 10 I5 --- ObsID [321/21035]? ObsID (1)
12- 12 A1 --- f_ObsID Flag on observation (2)
14- 24 F11.7 deg RAdeg [40.05/345.25] Aim point, Right Ascension,
decimal degrees (J2000) (3)
26- 36 F11.7 deg DEdeg [-35.7/65.2] Aim point, Declination,
decimal degrees (J2000) (3)
38- 56 A19 "datime" Date UT Observation Start Time, ISO 8601 format
58- 61 I4 ks Exp [5/1127] Exposure time (4)
63 I1 --- NFl [1/3]? Number of flaring intervals (5)
64 A1 --- --- [;]
65- 67 F3.1 ks Dur [0.5/3]? Combine duration of the flaring
intervals (5)
69- 73 F5.2 arcsec dRA [-0.8/0.5]? Offset, in Right Ascension
75- 79 F5.2 arcsec dDE [-0.6/0.7]? Offset, in Declination
81- 81 A1 --- Mode Observing mode, F=Faint mode;
V=Very Faint mode
--------------------------------------------------------------------------------
Note (1): All observations were continuous.
Note (2): Flag as follows:
d = Indicates Obs. ID that all other observations are reprojected to for
alignment purposes. This Obs. ID was chosen for reprojection as it
had the longest initial exposure time, before flaring intervals were
removed;
e = The last ObsID for each set is the merged (total time) on source.
Note (3): Aim point represents exposure-time weighted value
Note (4): The exposure times shown have been corrected for removed data that
were affected by high background.
Note (5): These intervals were rejected from further analyses.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 8 I3 --- Nsrc [4/180] Total number, X-ray sources (10)
10- 13 F4.1 [10-7W] logL50 [36.1/38.2] Log of luminosity
at 50% completeness limit, erg/s
15- 18 F4.1 [10-7W] logL90 [36.4/38.4] Log of luminosity
at 90% completeness limit, erg/s
20- 24 F5.2 --- KPL [0.6/82] Single power-law fit
normalization (11)
26- 31 F6.2 --- E_KPL [0.5/146]? Upper uncertainty on KPL
33- 37 F5.2 --- e_KPL [0.3/49] Lower (or symmetric)
uncertainty on KPL
39- 42 F4.2 --- alpha [1.3/3.3] single power-law slope fit
44- 47 F4.2 --- E_alpha [0.1/1.1]? Upper uncertainty on alpha
49- 52 F4.2 --- e_alpha [0.06/0.8] Lower (or symmetric)
uncertainty on alpha
54- 55 I2 --- C-PL [6/54] C-statistic, power-law model fit
57- 61 F5.3 --- P-PL Null-hypothesis probability, power-law fit (12)
63- 68 F6.2 --- KBPL [2.7/159] Broken 2 power-law fit
normalization (13)
70- 74 F5.2 --- E_KBPL [2.9/37.2]? Upper uncertainty on KBPL
76- 80 F5.2 --- e_KBPL [1.5/28.6] Lower (or symmetric)
uncertainty on KBPL
82- 85 F4.2 --- alpha1 [0.23/1.83] first power-law slope fit
87- 90 F4.2 --- E_alpha1 [0.14/1.7]? Upper uncertainty on alpha1
92- 95 F4.2 --- e_alpha1 [0.09/0.8]? Lower (or symmetric)
uncertainty on alpha1
97-100 F4.2 --- alpha2 [1.8/3.7] second power-law fit
102-105 F4.2 --- E_alpha2 [0.1/1]? Upper uncertainty on alpha2
107-110 F4.2 --- e_alpha2 [0.1/1.1]? Lower (or symmetric)
uncertainty on alpha2
112-113 I2 --- C-BPL [8/39] C-statistic, broken power-law model fit
115-119 F5.3 --- P-BPL Null-hypothesis probability, power-law fit (12)
121-124 F4.1 [10-7W] logLx [38.8/40.5] Log of integrated X-ray
luminosity, LX, broken power-law model
126-128 F3.1 [10-7W] E_logLx [0/0.8]? Upper uncertainty on logLx
130-132 F3.1 [10-7W] e_logLx [0/0.3] Lower (or symmetric) uncertainty
on logLx
135-135 I1 --- Flag [1/2]? Fitting flag (14)
--------------------------------------------------------------------------------
Note (10): Total number of X-ray sources detected within the galactic
boundaries defined in Table 1.
Note (11): Single power-law models are derived following Eq. (1) with a fixed
cut-off luminosity of Lc=3*1039erg/s.
Note (12): The null-hypothesis probability is calculated following the
prescription in Kaastra (2017A&A...605A..51K 2017A&A...605A..51K).
Note (13): Broken power-law models are derived following Eq. (2) with a
fixed break luminosity of Lb=3*1037erg/s and cut-off luminosity
of Lc=3*1039ergs-1.
Note (14): Fitting flags as follows:
1 = for NGC 1387 the alpha1 in the broken power-law was fixed due to
shallow Chandra depth (see Section 4.2);
2 = for NGC 4406 both the alpha1 and alpha2 slopes in the broken power-law
were fixed due to shallow Chandra depth (see Section 4.2).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 7 I2 --- C-PL [6/54] C-statistic, power-law model
9- 13 F5.3 --- P-PL Null-hypothesis probability, power-law model
15- 16 I2 --- C-BPL [8/39] C-statistic, broken power-law model
18- 22 F5.3 --- P-BPL Null-hypothesis probability,
broken power-law model
24- 25 I2 --- C-Mstar [15/62] C-statistic, stellar-mass dependent
model
27- 31 F5.3 --- P-Mstar Null-hypothesis probability,
stellar-mass dependent model
33- 34 I2 --- C-MSN [13/54] C-statistic, stellar-mass and
SN dependent model
36- 40 F5.3 --- P-MSN Null-hypothesis probability, stellar-mass
and SN dependent model
42- 43 I2 --- C-GC [13/56]? C-statistic, GC LMXB population
45- 45 A1 --- l_P-GC Limit flag for P-GC
47- 51 F5.3 --- P-GC ? Null-hypothesis probability, GC LMXB population
53- 54 I2 --- C-T [14/64] C-statistic, global model
56- 60 F5.3 --- P-T Null-hypothesis probability, global model
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- NGC [1023/7457] Galaxy NGC number
6- 8 I3 --- Seq [1/479] Point-source identification number
within the galaxy
10- 19 F10.6 deg RAdeg Right Ascension, decimal degrees (J2000)
21- 30 F10.6 deg DEdeg Declination, decimal degrees (J2000)
32- 34 F3.1 arcmin theta [0/6.6] Angular offset from Chandra aim
point
36- 42 F7.1 ct NFB [1/41652] Net background subtracted
0.5-7keV counts
44- 48 F5.1 ct e_NFB [1/218] Uncertainty in NFB
50- 55 F6.3 10+22cm-2 NH [0.014/11] Best fit hydrogen column
density (1)
56 A1 --- l_NH [uf] u: upper limit flag on NH;
f: fixed values
57- 62 F6.3 10+22cm-2 e_NH [0.014/9]? Uncertainty in NH
64- 67 F4.2 --- Gamma [0.09/3.3] Best fit photon index (1)
68 A1 --- l_Gamma [uf] u: upper limit flag on Gamma;
f: fixed values
69- 73 F5.2 --- e_Gamma [0.02/2.5]? Uncertainty in Gamma
75- 79 F5.1 [mW/m2] logFfb [-22/-12] log of 0.5-8keV flux, erg/s/cm2
81- 84 F4.1 [10-7W] logLfb [30.5/40.3] log of 0.5-8keV luminosity;
in erg/s units
86- 86 I1 --- LOC [1/3] Flag indicating location of source
in galaxy (2)
88- 88 A1 --- OPT [BFGU] HST (optical) classification of
the source (3)
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Note (1): Values based on spectral fits to an absorbed power-law model
(TBABSGal * TBABS * POW in xspec). For sources with small numbers of
counts (<20 net counts), we adopted only Galactic absorption appropriate
for each galaxy and a photon index of Γ=1.7.
Note (2): Flag indicating location of source in galaxy as follows:
1 = source is within the Ks-band footprint adopted in Table 1, and outside
a central region of avoidance, if applicable. All XLF calculations are
based on Flag=1 sources.
2 = source is located in the central region of avoidance due to either the
presence of an AGN or very high levels of source confusion.
3 = source is outside the 20mag/arcsec2 Ks-band ellipse of the galaxy.
Note (3): HST classification of the source, whenever the source is within the
footprint of the galaxy, as defined in Table 1.
Classification codes as follows:
F = field LMXB (1238 occurrences);
G = direct-GC LMXB (604 occurrences);
B = background sources (105 occurrences);
U = unclassified sources (1976 occurrences).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 22-Jul-2020