J/ApJ/685/958 Spitzer and Chandra sources in galactic center (Arendt+ 2008)
Comparison of 3.6-8.0 µm Spitzer/IRAC Galactic Center survey point sources
with Chandra X-ray point sources in the central 40x40 parsecs.
Arendt R.G., Gezari D.Y., Stolovy S.R., Sellgren K., Smith R.,
Ramirez S.V., Yusef-Zadeh F., Law C.J., Smith H.A., Cotera A.S.,
Moseley S.H.
<Astrophys. J., 685, 958-970 (2008)>
=2008ApJ...685..958A 2008ApJ...685..958A
ADC_Keywords: Infrared sources ; Photometry, infrared ; X-ray sources
Keywords: Galaxy: center - infrared: stars - X-rays: binaries
Abstract:
We have studied the correlation between 2357 Chandra X-ray point
sources in a 40x40pc field and ∼20000 infrared sources we observed in
the corresponding subset of our 2x1.4° Spitzer/IRAC Galactic
Center Survey at 3.6-8.0um, using various spatial and X-ray hardness
thresholds. The correlation was determined for source separations of
less than 0.5", 1", or 2". Only the soft X-ray sources show any
correlation with infrared point sources on these scales, and that
correlation is very weak. The upper limit on hard X-ray sources that
have infrared counterparts is <1.7% (3σ). However, because of
the confusion limit of the IR catalog, we only detect IR sources with
absolute magnitudes ≲1. As a result, a stronger correlation with
fainter sources cannot be ruled out. Only one compact IR source, IRS
13, coincides with any of the dozen prominent X-ray emission features
in the 3x3pc region centered on Sgr A*, and the diffuse X-ray and IR
emission around Sgr A* seems to be anticorrelated on a few-arcsecond
scale. We compare our results with previous identifications of
near-infrared companions to Chandra X-ray sources.
Description:
Spitzer/IRAC Galactic Center survey observations cover four broad
bands at 3.6, 4.5, 5.8, and 8um with a nominal resolution of ∼2". We
calculated the correlation between 2357 hard and soft Chandra X-ray
sources cataloged by Muno et al. (2003, Cat. J/ApJ/589/225) and the
corresponding ∼20000 Spitzer/IRAC IR point sources. The IR sources are
a small subset of our full catalog (Ramirez et al. 2008, Cat. II/295).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table7.dat 110 115 *IR and X-ray sources coinciding within 1" (no
physical association implied)
--------------------------------------------------------------------------------
Note on table7.dat: Positional coincidence does not necessarily imply a physical
association of IR and X-ray sources. In fact, ∼70% of the objects on this list
are likely to be random positional coincidences of unrelated sources along the
line of sight.
--------------------------------------------------------------------------------
See also:
B/chandra : The Chandra Archive Log (CXC, 1999-)
II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)
II/295 : Spitzer IRAC survey of the galactic center (Ramirez+, 2008)
J/ApJ/589/225 : Chandra X-ray sources toward Galactic Center (Feigelson+,
2003)
J/ApJ/613/1179 : X-ray sources in Galactic Center (Muno+, 2004)
J/ApJS/181/110 : Galactic center x-ray sources (Muno+, 2009)
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [SSTGC]
7- 13 I7 --- SSTGC IR source identification number (1)
15- 23 F9.5 deg RAdeg IR right ascension in decimal degree (J2000)
25- 33 F9.5 deg DEdeg IR declination in decimal degree (J2000)
35- 39 F5.2 mag [3.6] ? Spitzer/IRAC 3.6um band magnitude
41- 45 F5.2 mag [4.5] ? Spitzer/IRAC 4.5um band magnitude
47- 51 F5.2 mag [5.8] ? Spitzer/IRAC 5.8um band magnitude
53- 57 F5.2 mag [8.0] ? Spitzer/IRAC 8.0um band magnitude
59- 63 A5 --- --- [CXOGC]
65- 80 A16 --- CXOGC X-ray source identification (JHHMMSS.s+DDMMSS) (2)
82- 90 F9.5 deg RAXdeg X-ray right ascension in decimal degree (J2000)
92-100 F9.5 deg DEXdeg X-ray declination in decimal degree (J2000)
102-105 A4 --- Sp Spectrum (soft for detected in the 0.5-2.0keV
band or hard for not detected in this band)
107-110 F4.2 arcsec Sep Separation between IR and X-ray source positions
--------------------------------------------------------------------------------
Note (1): Ramirez et al., 2008, Cat. II/295. in Simbad.
Note (2): Muno et al., 2003, Cat. J/ApJ/589/225. in
Simbad.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 14-Dec-2010