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J/ApJ/749/130   X-ray binaries in NGC 1291 with Chandra           (Luo+, 2012)

Probing the X-ray binary populations of the ring galaxy NGC 1291. Luo B., Fabbiano G., Fragos T., Kim D.-W., Belczynski K., Brassington N.J., Pellegrini S., Tzanavaris P., Wang J., Zezas A. <Astrophys. J., 749, 130 (2012)> =2012ApJ...749..130L
ADC_Keywords: Binaries, X-ray ; Galaxies, nearby ; X-ray sources Keywords: galaxies: individual: (NGC 1291) - X-rays: galaxies - galaxies: luminosity function, mass function - X-rays: binaries Abstract: We present Chandra studies of the X-ray binary (XRB) populations in the bulge and ring regions of the ring galaxy NGC 1291. We detect 169 X-ray point sources in the galaxy, 75 in the bulge and 71 in the ring, utilizing the four available Chandra observations totaling an effective exposure of 179 ks. We report photometric properties of these sources in a point-source catalog. There are ~40% of the bulge sources and ~25% of the ring sources showing >3σ long-term variability in their X-ray count rate. The X-ray colors suggest that a significant fraction of the bulge (~75%) and ring (~65%) sources are likely low-mass X-ray binaries (LMXBs). The spectra of the nuclear source indicate that it is a low-luminosity active galactic nucleus (AGN) with moderate obscuration; spectral variability is observed between individual observations. We construct 0.3-8.0 keV X-ray luminosity functions (XLFs) for the bulge and ring XRB populations, taking into account the detection incompleteness and background AGN contamination. We reach 90% completeness limits of ~1.5x1037 and ~2.2x1037 erg/s for the bulge and ring populations, respectively. Both XLFs can be fit with a broken power-law model, and the shapes are consistent with those expected for populations dominated by LMXBs. We perform detailed population synthesis modeling of the XRB populations in NGC 1291, which suggests that the observed combined XLF is dominated by an old LMXB population. We compare the bulge and ring XRB populations, and argue that the ring XRBs are associated with a younger stellar population than the bulge sources, based on the relative overdensity of X-ray sources in the ring, the generally harder X-ray color of the ring sources, the overabundance of luminous sources in the combined XLF, and the flatter shape of the ring XLF. Description: NGC 1291 has been observed with the S3 chip of Chandra Advanced CCD Imaging Spectrometer (ACIS) at four epochs. The four observations taken in 2000 Jun 27 (obsID 795), 2000 Dec 7 (obsID 2059), 2010 May 4 (obsID 11272) and 2010 May 8 (obsID 11273) have exposure times, ranging from 37 ks to 70 ks. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 203 169 Chandra point-source catalog in NGC 1291
See also: B/chandra : The Chandra Archive Log (CXC, 1999-2013) J/ApJS/192/10 : Chandra ACIS survey in 383 nearby galaxies. I. (Liu, 2011) J/ApJ/664/458 : Spectral fit of ULX sources (Devi+, 2007) J/ApJS/157/59 : Ultraluminous X-ray sources in nearby galaxies (Liu+, 2005) J/ApJ/602/231 : Chandra X-ray point sources in nearby galaxies (Colbert+, 2004) J/MNRAS/344/134 : Chandra ultraluminous X-ray sources (Humphrey+, 2003) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 3 I3 --- XID [1/169] X-ray source index number (1) 5- 6 I2 h RAh [3] X-ray hour of Right Ascension (J2000) 8- 9 I2 min RAm [16/17] Minute of Right Ascension (J2000) 11- 15 F5.2 s RAs Second of Right Ascension (J2000) 17 A1 --- DE- [-] X-ray sign of the Declination (J2000) 18- 19 I2 deg DEd [41] X-ray degree of Declination (J2000) 21- 22 I2 arcmin DEm [0/13] Arcminute of Declination (J2000) 24- 27 F4.1 arcsec DEs Arcsecond of Declination (J2000) 29- 31 F3.1 arcmin Off [0.7/9.3] Off-Axis angle of X-ray source (2) 33- 35 F3.1 arcmin Drad Radial distance of X-ray source to galaxy nucleus 37- 42 F6.1 ct FB [4.9/3835] Full (0.3-8.0 keV) band source counts 44- 47 F4.1 ct e_FB Lower 1σ error in FB 49- 52 F4.1 ct E_FB Upper 1σ error in FB 54- 59 F6.1 ct SB [6.7/2920] Soft (0.3-2.0 keV) band source counts 61- 64 F4.1 ct e_SB ?=-1.0 Lower 1σ error in SB (3) 66- 69 F4.1 ct E_SB ?=-1.0 Upper 1σ error in SB (3) 71- 76 F6.1 ct CSB [5.1/2695] Conventional soft (0.5-2.0 keV) band source counts 78- 81 F4.1 ct e_CSB ?=-1 Lower 1σ error in CSB (3) 83- 86 F4.1 ct E_CSB ?=-1 Upper 1σ error in CSB (3) 88- 93 F6.1 ct HB [5.6/1559] Hard (2.0-8.0 keV) band source counts 95- 98 F4.1 ct e_HB ?=-1 Lower 1σ error in HB (3) 100-103 F4.1 ct E_HB ?=-1 Upper 1σ error in HB (3) 105-110 F6.1 ct SB1 [4.9/1077] Soft (0.3-1.0keV) band #1 source counts 112-115 F4.1 ct e_SB1 ?=-1 Lower 1σ error in SB1 (3) 117-120 F4.1 ct E_SB1 ?=-1 Upper 1σ error in SB1 (3) 122-127 F6.1 ct SB2 [5.1/1789] Soft (1.0-2.0keV) band #2 source counts 129-132 F4.1 ct e_SB2 ?=-1 Lower 1σ error in SB2 (3) 134-137 F4.1 ct E_SB2 ?=-1 Upper 1σ error in SB2 (3) 139-146 E8.3 s Texp [9300/172000] Full band effective exposure time (4) 148-152 F5.2 --- SC [-1.27/0.98] Soft color ((M-S)/T) (5) 154-157 F4.2 --- e_SC ?=-1 Lower 1σ error in SC 159-162 F4.2 --- E_SC ?=-1 Upper 1σ error in SC 164-168 F5.2 --- HC [-0.92/1.05] Hard color ((H-M)/T) (5) 170-173 F4.2 --- e_HC ?=-1 Lower 1σ error in HC 175-178 F4.2 --- E_HC ?=-1 Upper 1σ error in HC 180-183 F4.2 --- Gamma [0.6/4.3] Photon index Γ (6) 185-192 E8.3 10-7W LX Observed full-band X-ray luminosity; erg/s 194-197 F4.1 --- Var [0/45.1]?=-1 Full-band flux variability statistical significance (7) 199-203 A5 --- Reg Region flag (Bulge, Ring or Other) (8)
Note (1): Listed in order of increasing right ascension; <[LFF2012] NNN> in Simbad. Note (2): This is the distance between the source position and the average aim point (see Section 2). Note (3): A -1.0 value indicates upper limits. Note (4): Determined from the exposure map, which has been corrected for vignetting and quantum-efficiency degradation. Note (5): The X-ray colors are defined as HC=(H-M)/T and SC=(M-S)/T, where S , M , H , and T are the count rates in the 0.3-1.0 keV, 1.0-2.0 keV, 2.0-8.0 keV, and 0.3-8.0 keV bands, respectively. Note (6): Derived from spectral fitting, or set to Γ = 1.7 if the number of full-band counts is smaller than 30. Note (7): See Section 4.3 for details. It is set to -1.0 if the flux variability is not available. Note (8): The flag is "Bulge" if the source is located in the bulge, "Ring" if the source is in the ring, or "Other" if the source is neither in the bulge nor in the ring.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 27-Nov-2013
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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