J/A+A/458/245 Obs. of 2 Unidentified Gamma-ray Sources (La Palombara+, 2006)
XMM-Newton and ESO observations of the two Unidentified Gamma-ray Sources
3EG J0616-3310 and 3EG J1249-8330.
La Palombara N., Mignani R.P., Hatziminaoglou E., Schirmer M., Bignami G.F.,
Caraveo P.
<Astron. Astrophys. 458, 245 (2006)>
=2006A&A...458..245L 2006A&A...458..245L
ADC_Keywords: Gamma rays ; X-ray sources ; Pulsars
Keywords: stars: neutron - gamma-rays: observations -
X-rays: general, surveys, catalogues
Abstract:
The systematic X-ray and optical coverage of low-latitude unidentified
gamma-ray sources, aiming at sources with high X-ray/optical flux
ratio, seems one of the most promising ways to spot INS candidate
counterparts. We have focussed on two middle-latitude, probably
galactic, EGRET sources: 3EG J0616-3310 and 3EG J1249-8330. Here we
report on X-ray observations of the two gamma-ray error boxes
performed with XMM-Newton and on their optical follow-up carried on
with the Wide Field Imager at the ESO/MPG 2.2m telescope. Less than
half of the ∼300 sources detected by the X-ray coverage have no
optical counterparts. Among those, we have selected few interesting
sources with fX/fopt>100, which we consider promising INS
candidates.
Description:
We present the finding charts of the nine most interesting X-ray
sources, which have no candidate optical counterpart within 5arcsec
and are characterized by a high X-ray/optical flux ratio (i.e. greater
than 100). Moreover, we report Appendixes A and B of the paper. In
Appendix A we describe the source classification scheme, which is
based on the X-ray/optical flux ratio and is derived from the
Hamburg/RASS one, taking into account the different energy ranges of
ROSAT and XMM-Newton, the different spectral models and the different
optical filters. In Appendix B we describe how we calculated the
fluxes, based on the optical magnitudes.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
06 16 36.0 -33 10 12 3EG J0616-3310
12 24 54.4 -83 13 10 3EG J1249-8330
-----------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 70 8 Main characteristics of the 8 EPIC observations of
3EG J0616-3310 (Obs=1-4) & 3EG J1249-8330 (Obs=5-8)
table7.dat 96 9 Main characteristics of the X-ray sources with no
candidate optical counterpart and log(FX/Fopt)≳2
appendix.ps 81 7126 PostScript version of Appendix
chart.pdf 512 95 PDF version of figure 1
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See also:
I/239 : The Hipparcos Main Catalogue (ESA, 1997)
VII/206 : General Photometry of Galaxies (Prugniel+, 1998)
VII/248 : Quasars and Active Galactic Nuclei (12th Ed.) (Veron+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 I1 --- Obs EPIC field sequential reference number
3- 5 I3 --- Rev Revolution number of XMM
7- 16 A10 "YYYY-MM-DD" ObsDate Observation date
18- 25 A8 "h:m:s" ObsTime Observation time (hh:mm:ss)
27- 28 I2 h RAh Right ascension (J2000)
30- 31 I2 min RAm Right ascension (J2000)
33- 36 F4.1 s RAs Right ascension (J2000)
38 A1 --- DE- Declination sign (J2000)
39- 40 I2 deg DEd Declination (J2000)
42- 43 I2 arcmin DEm Declination (J2000)
45- 48 F4.1 arcsec DEs Declination (J2000)
50- 52 F3.1 ks PN Exposure time for PN instrument
54- 57 F4.1 ks MOS1 Exposure time for MOS1 instrument
59- 62 F4.1 ks MOS2 Exposure time for MOS2 instrument
64- 67 F4.1 10+20cm-2 NH Hydrogen column density
69- 70 I2 --- Det Number of detected sources
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1 I1 --- Obs EPIC field sequential reference number
3- 6 A4 --- --- [XMMU]
8- 23 A16 --- XMMU XMMU designation (JHHMMSS.s+DDMMSS)
25- 47 A23 --- Bands Detection bands
49- 50 A2 --- l_kTbt [<≥ ] Limit flag on kTbt
51- 53 F3.1 keV kTbt Range of possible kT temperature for
thermal bremsstrahlung spectrum
54 A1 --- --- [-]
55 I1 keV kTbt2 ? Range of possible kT temperature for
thermal bremsstrahlung spectrum
57- 58 A2 --- l_kTbb [<≥ ] Limit flag on kTbb
59- 61 F3.1 keV kTbb Range of possible kT temperature for
thermal blackbody spectrum
62 A1 --- --- [-]
63- 65 F3.1 keV kTbb2 ? Range of possible kT temperature for
thermal blackbody spectrum
67- 68 A2 --- l_Gamma [<≥ ] Limit flag on Gamma
69- 71 F3.1 keV Gamma Range of photon index for a power law
spectrum
72 A1 --- --- [-]
73- 75 F3.1 keV Gamma2 ? Range of photon index for a power law
spectrum
77- 81 F5.2 10-17W/m2 Flux Source flux in 0.3-10keV energy range
83- 86 F4.2 10-17W/m2 e_Flux rms uncertainty on Flux
88- 91 F4.2 [-] log(FX/Fopt) Lower limit of X-ray-to-optical flux ratio
93- 96 F4.2 [-] e_log(FX/Fopt) rms uncertainty on log(FX/Fopt)
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Acknowledgements: Nicola La Palombara, nicola(at)iasf-milano.inaf.it
(End) Patricia Vannier [CDS] 12-Oct-2006