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CHANGALXRB - Chandra X-Ray Binary Catalog of SINGS Galaxies

 HEASARC
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Overview

The authors of this catalog presented new Chandra constraints on the X-ray luminosity functions (XLFs) of X-ray binary (XRB) populations, as well as their scaling relations, for a sample of 38 nearby galaxies (D = 3.4-29 Mpc). The galaxy sample is drawn primarily from the Spitzer Infrared Nearby Galaxies Survey (SINGS) and contains a wealth of Chandra (5.8 Ms total) and multiwavelength data, allowing for star formation rates (SFRs) and stellar masses (M*) to be measured on subgalactic scales. The authors divided the 2478 X-ray-detected sources into 21 subsamples in bins of specific SFR (sSFR=SFR/M*) and constructed XLFs. To model the XLF dependence on sSFR, they fitted a global XLF model, containing contributions from high-mass XRBs (HMXBs), low-mass XRBs (LMXBs), and background sources from the cosmic X-ray background that respectively scale with SFR, M*, and sky area. They found an HMXB XLF that is more complex in shape than previously reported and an LMXB XLF that likely varies with sSFR, potentially due to an age dependence. When applying the global model to XLF data for each individual galaxy, the authors discovered a few galaxy XLFs that significantly deviated from their model beyond statistical scatter. Most notably, relatively low-metallicity galaxies have an excess of HMXBs above ~1038erg/s, and elliptical galaxies that have relatively rich populations of globular clusters (GCs) show excesses of LMXBs compared to the global model. Additional modeling of how the XRB XLF depends on stellar age, metallicity, and GC specific frequency is required to sufficiently characterize the XLFs of galaxies.

In this work, the authors utilized 5.8 Ms of Chandra ACIS data, combined with UV-to-IR observations, for 38 nearby (D < ~30 Mpc) Spitzer Infrared Nearby Galaxies Survey (SINGS; Kennicutt+ 2003PASP..115..928K) galaxies to revisit scaling relations of the HMXB and LMXB X-ray luminosity functions (XLFs) with SFR and M*, respectively.

This table contains the X-ray properties for 4442 X-ray point sources, including those with LX < 1035erg/s, which were excluded from the XLF analysis.

Catalog Bibcode

2019ApJS..243....3L

References

X-ray binary luminosity function scaling relations for local galaxies based on
subgalactic modeling.
    Lehmer B.D., Eufrasio R.T., Tzanavaris P., Basu-Zych A., Fragos T.,
    Prestwich A., Yukita M., Zezas A., Hornschemeier A.E., Ptak A.
   <Astrophys. J. Suppl. Ser., 243, 3-3 (2019)>
   =2019ApJS..243....3L

Provenance

This table was created by the HEASARC in April 2023 based upon the CDS Catalog J/ApJS/243/3 file table7.dat.

Parameters

Name
The source designation based on the NGC name (NNNN) and source number (XXX) given by '[LET2019] NGC NNNN XXX', as registered by the CDS Dictionary of Nomenclature.

RA
The right ascension of the source, given in J2000.0 decimal degrees to a precision of 10-6 degrees in the originating table.

Dec
The declination of the source, given in J2000.0 decimal degrees to a precision of 10-6 degrees in the originating table.

LII
The galactic longitude of the source. This parameter has been added by the HEASARC and is derived from the J2000.0 source position.

BII
The galactic latitude of the source. This parameter has been added by the HEASARC and is derived from the J2000.0 source position.

Off_Axis
The off-axis angle, given in arcmin, with respect to the average aim point of the Chandra observations.

Counts
The net (background-subtracted) counts in the 0.5-7keV band.

Counts_Error
The 1-sigma uncertainty in the net counts, in the 0.5-7keV band.

NH_Limit
This flag is set to '<' if the corresponding best-fit column density is an upper limit rather than a value.

NH
The best-fit column density, in cm-2, based on spectral fits to an absorbed power-law model (TBABS * POW in xspec). For sources with small numbers of counts (<20 net counts), the authors adopted Galactic absorption appropriate for each galaxy and a photon index (Gamma) = 1.7.

NH_Error
The 1-sigma uncertainty on the best-fit column density, in cm-2, based on spectral fits to an absorbed power-law model (TBABS * POW in xspec). For sources with small numbers of counts (<20 net counts), the authors adopted Galactic absorption appropriate for each galaxy and a photon index (Gamma)=1.7.

Spectral_Index_Limit
This flag is set to '<' if the corresponding best-fit photon index (Gamma) is an upper limit rather than a value.

Spectral_Index
The best-fit photon index (Gamma) parameter, based on spectral fits to an absorbed power-law model (TBABS * POW in xspec). For sources with small numbers of counts (<20 net counts), the authors adopted Galactic absorption appropriate for each galaxy and a photon index (Gamma) = 1.7.

Spectral_Index_Error
The 1-sigma uncertainty in the photon index (Gamma), based on spectral fits to an absorbed power-law model (TBABS * POW in xspec). For sources with small numbers of counts (<20 net counts), the authors adopted Galactic absorption appropriate for each galaxy and a photon index (Gamma) = 1.7.

Log_Flux
The logarithm of 0.5-8keV source flux in units of erg/s/cm2.

Log_Lx
The logarithm of 0.5-8keV source luminosity in units of erg/s.

Location_Flag
This flag indicates a note about the location of the source within the galaxy. The meanings for the flag values are as follows: 

      1 = Indicates that the source is within the Ks-band footprint adopted
          in Table 1 of the reference paper, and outside a central region of
          avoidance, if applicable. All XLF calculations are based on Flag=1
          sources.

      2 = This indicates that the source is within the Ks-band footprint, but
          has a luminosity of L<10+35erg/s, and was thus excluded from the
          XLF analysis.

      3 = Indicates that the source is outside the 20-mag/arcsec2 Ks-band
          ellipse of the galaxy, but within the "total" Ks-band ellipse.

      4 = The source is located in the central region of avoidance due to
          either the presence of an AGN or very high levels of source
          confusion.

      5 = This indicates that the source is outside the "total" Ks-band ellipse.

Contact Person

Questions regarding the CHANGALXRB database table can be addressed to the HEASARC Help Desk.
Page Author: Browse Software Development Team
Last Modified: Friday, 14-Apr-2023 19:03:56 EDT