J/A+A/645/A18 SVOM-ECLAIRs known X-ray sources catalogue (Dagoneau+, 2021)
Onboard catalogue of known X-ray sources for SVOM-ECLAIRs.
Dagoneau N., Schanne S., Rodriguez J., Atteia J.-L., Cordier B.
<Astron. Astrophys. 645, A18 (2021)>
=2021A&A...645A..18D 2021A&A...645A..18D (SIMBAD/NED BibCode)
ADC_Keywords: X-ray sources ; Spectroscopy
Keywords: instrumentation: miscellaneous - telescopes - catalogs -
X-rays: general - techniques: image processing
Abstract:
The SVOM mission currently under development will carry various
instruments, and in particular the coded-mask telescope ECLAIRs, with
a large field of view of about 2sr, operating in the 4-150keV
energy band. The main goal of ECLAIRs is to detect high-energy
transients such as gamma-ray bursts. Its onboard trigger software will
search for new hard X-ray sources appearing in the sky, as well as
peculiar behaviour (e.g. strong outbursts) from known sources, in
order to repoint the satellite to perform follow-up observations with
its onboard narrow-field-of-view instruments. The presence of known
X-ray sources must be disentangled from the appearance of new sources.
This is done with the help of an onboard source catalogue, which we
present in this paper. As an input we use catalogues of X-ray sources
detected by Swift/BAT and MAXI/GSC and we study the influence of the
sources on ECLAIRs' background level and on the quality of the
sky-image reconstruction process. We show that the influence of the
sources depends on the pointing direction on the sky, on the energy
band, and on the exposure time. In the Galactic centre, the
contribution from known sources largely dominates the cosmic X-ray
background, which is, on the contrary, the main background in sky
regions lacking strong sources. We also demonstrate the need to clean
the contributions of these sources in order to maintain a low noise
level in the sky images and to maintain a low threshold for the
detection of new sources without introducing false triggers. We
briefly describe one of our cleaning methods and its challenges.
Finally, we present the overall structure of the onboard catalogue and
the way it will be used to perform the source cleaning and disentangle
detections of new sources from outbursts of known sources.
Description:
This table lists the 1793 sources detected by MAXI/GSC and/or
Swift/BAT used to study the influence of these sources on the sky
images produced by the SVOM-ECLAIRs telescope (4-150keV). The table
contains the simple mean spectrum that we computed from the data given
in the MAXI/GSC standard products and/or from the Swift/BAT 105-month
survey (Oh et al., 2018, J/ApJS/235/4).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 400 1793 Table of all 1793 sources
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See also:
J/ApJS/235/4 : The 105-month Swift-BAT all-sky hard X-ray survey (Oh+, 2018)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 42 A42 --- Name Source name (1)
44- 76 A33 --- SimbadMainId Source main ID in CDS
78- 81 I4 --- BAT105mId ? Source ID in Oh et al., 2018,
J/ApJS/235/4
83- 89 F7.3 deg RAdeg Right ascension (J2000)
91- 97 F7.3 deg DEdeg Declination (J2000)
99-100 A2 --- Sp [BP ] Spectrum model (2)
102-103 I2 keV Elow [4/14] Low energy bound
105-107 I3 keV Ehigh [20/150] High energy bound
109-117 E9.3 ph/cm2/s/keV K Normalisation (3)
119-128 E10.3 --- alpha Low energy photon index
130-139 E10.3 --- beta ? High energy photon index
(only for Sp=BP)
141-149 E9.3 keV Ex ? Energy break (only for Sp=BP)
151-159 E9.3 --- fitErr ? Fit quadratic error (4)
161-169 E9.3 --- chi2r Fit reduced chi square (5)
171-172 I2 --- NptsFit Number of fitted points (6)
174-182 E9.3 ph/cm2/s F2-4 ? MAXI/GSC median flux in 2-4keV
184-192 E9.3 ph/cm2/s e_F2-4 ? MAXI/GSC median flux error in 2-4keV
194-202 E9.3 ph/cm2/s F4-10 ? MAXI/GSC median flux in 4-10keV
204-212 E9.3 ph/cm2/s e_F4-10 ? MAXI/GSC median flux error
in 4-10keV
214-222 E9.3 ph/cm2/s F10-20 ? MAXI/GSC median flux in 10-20keV
224-232 E9.3 ph/cm2/s e_F10-20 ? MAXI/GSC median flux error
in 10-20keV
234-243 E10.3 ph/cm2/s F14-20 ? Swift/BAT survey flux in 14-20keV
245-253 E9.3 ph/cm2/s e_F14-20 ? Swift/BAT survey flux error
in 14-20keV
255-264 E10.3 ph/cm2/s F20-24 ? Swift/BAT survey flux in 20-24keV
266-274 E9.3 ph/cm2/s e_F20-24 ? Swift/BAT survey flux error
in 20-24keV
276-285 E10.3 ph/cm2/s F24-35 ? Swift/BAT survey flux in 24-35keV
287-295 E9.3 ph/cm2/s e_F24-35 ? Swift/BAT survey flux error
in 24-35keV
297-306 E10.3 ph/cm2/s F35-50 ? Swift/BAT survey flux in 35-50keV
308-316 E9.3 ph/cm2/s e_F35-50 ? Swift/BAT survey flux error
in 35-50keV
318-327 E10.3 ph/cm2/s F50-75 ? Swift/BAT survey flux in 50-75keV
329-337 E9.3 ph/cm2/s e_F50-75 ? Swift/BAT survey flux error
in 50-75keV
339-348 E10.3 ph/cm2/s F75-100 ? Swift/BAT survey flux in 75-100keV
350-358 E9.3 ph/cm2/s e_F75-100 ? Swift/BAT survey flux error
in 75-100keV
360-369 E10.3 ph/cm2/s F100-150 ? Swift/BAT survey flux in 100-150keV
371-379 E9.3 ph/cm2/s e_F100-150 ? Swift/BAT survey flux error
in 100-150keV
381-390 E10.3 ph/cm2/s F150-195 ? Swift/BAT survey flux in 150-195keV
392-400 E9.3 ph/cm2/s e_F150-195 ? Swift/BAT survey flux error
in 150-195keV
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Note (1): Name is the one of the source in the MAXI/GSC standard products or
the one from the Swift/BAT 105-month survey if the source is not listed in
the MAXI/GSC standard products.
Note (2): Spectrum model code as follows:
P = Simple powerlaw
BP = Broken powerlaw
Note (3): K in photons/cm2/s/keV at 1keV unit
Note (4): 0 is set for sources that are only listed in the Swift/BAT 105-month
survey (and not in the MAXI/GSC standard products).
Spectra are retrieved from J/ApJS/235/4.
Note (5): Only for sources in MAXI/GSC standard products. Spectrum for sources
that are only listed in the Swift/BAT 105-month survey are retrieved from
J/ApJS/235/4.
Note (6): Reduced chi-squared for sources that are only listed in the Swift/BAT
105-month survey are retrieved from J/ApJS/235/4.
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Acknowledgements:
Nicolas Dagoneau, nicolas.dagoneau(at)cea.fr
(End) Patricia Vannier [CDS] 22-Oct-2020