J/ApJ/756/33 X-ray sources near 2 bright γ-ray sources (Cheung+, 2012)
Chandra X-ray observations of the two brightest unidentified high Galactic
latitude Fermi-LAT γ-ray sources.
Cheung C.C., Donato D., Gehrels N., Sokolovsky K.V., Giroletti M.
<Astrophys. J., 756, 33 (2012)>
=2012ApJ...756...33C 2012ApJ...756...33C
ADC_Keywords: X-ray sources ; Gamma rays
Keywords: galaxies: active; gamma rays: general; pulsars: general
X-rays: general
Abstract:
We present Chandra ACIS-I X-ray observations of 0FGL J1311.9-3419 and
0FGL J1653.4-0200, the two brightest high Galactic latitude
(|b|>10°) γ-ray sources from the three-month Fermi Large
Area Telescope (LAT) bright source list that are still unidentified.
Both were also detected previously by EGRET, and despite dedicated
multi-wavelength follow-up, they are still not associated with
established classes of γ-ray emitters like pulsars or radio-loud
active galactic nuclei. X-ray sources found in the ACIS-I fields of
view are cataloged, and their basic properties are determined. These
are discussed as candidate counterparts to 0FGL J1311.9-3419 and
0FGL J1653.4-0200, with particular emphasis on the brightest of the 9
and 13 Chandra sources detected within the respective Fermi-LAT 95%
confidence regions. Further follow-up studies, including optical
photometric and spectroscopic observations, are necessary to identify
these X-ray candidate counterparts in order to ultimately reveal the
nature of these enigmatic γ-ray objects.
Description:
We obtained Chandra X-Ray Observatory observations of the two targets
(0FGL J1311.9-3419 and 0FGL J1653.4-0200) in 2010 Mar 21 and Jan 24,
with ∼20ks exposures each (ObsID 11790 and 11787).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 211 97 All X-ray sources found in the field of the four
ACIS-I chips in the Chandra observation of
0FGL J1311.9-3419
table6.dat 211 97 All X-ray sources found in the field of the four
ACIS-I chips in the Chandra Observation of
0FGL J1653.4-0200
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)
J/MNRAS/424/L64 : AGN/pulsar distinction for 2FGL sources (Mirabal+, 2012)
J/ApJ/753/83 : Associations to 1FGL sources (Ackermann+, 2012)
J/ApJ/742/66 : New Fermi/LAT extragalactic sources (Teng+, 2011)
J/ApJ/741/30 : Radio/γ-ray correlation in AGN (Ackermann+, 2011)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJ/706/L7 : The Fermi LAT sky as seen by INTEGRAL/IBIS (Ubertini+, 2009)
J/ApJ/700/597 : FERMI LAT detected blazars (Abdo+, 2009)
J/ApJS/183/46 : Fermi/LAT bright gamma-ray source list (0FGL) (Abdo+, 2009)
J/A+A/489/849 : Revised cat. of EGRET gamma-ray sources (Casandjian+, 2008)
J/A+A/458/245 : 2 Unidentified Gamma-ray Sources obs. (La Palombara+, 2006)
http://cxc.harvard.edu/cal/ASPECT/celmon/ : Chandra astrometric accuracy page
Byte-by-byte Description of file: table[56].dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/97] Running sequence number
4- 18 A15 --- CXOU Chandra name (HHMMSS.s+DDMMSS; J2000)
20- 28 F9.5 deg RAdeg Right ascension (J2000)
30- 38 F9.5 deg DEdeg Declination (J2000)
40- 43 F4.2 arcsec ePos [0.03/1.9] Source localization error (r)
45- 48 F4.1 arcmin Sep [0.7/10.2] Distance from the Chandra aim point
50- 52 I3 cm+2 Aeff [166/507] Effective area at the source
position at 1.5keV (1)
54- 58 F5.2 [-] logPks [-2/0]? Logarithm probability from the KS test
for variability (logPK-S)
60- 65 F6.1 ct Ncts [1.4/1674] Net counts in the 0.5-8keV band
67- 70 F4.1 ct E_Ncts [2.7/42] Positive error on Ncts
72- 75 F4.1 ct e_Ncts [1.3/41] Negative error on Ncts
77- 80 F4.1 --- NSig [0.5/40] Ncts significance
82- 88 E7.2 --- NPb [0/1] Probability (Pb) that the source counts
are solely from the background in the 0.5-8keV
90- 95 F6.1 ct Scts [-0.9/1139] Net counts in the 0.5-2keV band
97-100 F4.1 ct E_Scts [1.9/35] Positive error on Scts
102-105 F4.1 ct e_Scts [0/34] Negative error on Scts
107-110 F4.1 --- SSig [-0.5/33] Scts significance
112-118 E7.2 --- SPb [0/1] Probability (Pb) that the source counts
are solely from the background in the 0.5-2keV
120-124 F5.1 ct Hcts [-1.7/536] Counts in the 2-8keV band
126-129 F4.1 ct E_Hcts [1.9/25] Positive error on Hcts
131-134 F4.1 ct e_Hcts [0/24] Negative error on Hcts
136-139 F4.1 --- HSig [-0.9/22.1] Hcts significance
141-147 E7.2 --- HPb [0/1] Probability (Pb) that the source counts
are solely from the background in the 2-8keV
149-173 A25 --- USNO-B Potential counterpart match(es) from the
USNO B1.0 catalog (I/284) (from table 7)
175-191 A17 --- 2MASS Potential counterpart match from the
2MASS catalog (II/246) (from table 8)
193-211 A19 --- WISEP Potential counterpart match from the
WISEP catalog (II/307) (from table 9)
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Note (1): Lower values indicate sources located closer to the chip gaps
and edges.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 19-Mar-2014