J/MNRAS/318/1073 Hard spectrum ROSAT sources. I. (Page+, 2000)
A survey of hard spectrum ROSAT sources - I. X-ray source catalogue.
Page M.J., Mittaz J.P.D., Carrera F.J.
<Mon. Not. R. Astron. Soc. 318, 1073 (2000)>
=2000MNRAS.318.1073P 2000MNRAS.318.1073P
ADC_Keywords: X-ray sources - Surveys
Keywords: catalogues - surveys - X-rays: general
Abstract:
We present a catalogue of 147 serendipitous X-ray sources selected to
have hard spectra (α<0.5) from a survey of 188 ROSAT fields.
Such sources must be the dominant contributors to the X-ray background
at faint fluxes. We have used Monte Carlo simulations to verify that
our technique is very efficient at selecting hard sources: the survey
has ≥10 times as much effective area for hard sources as it has for
soft sources above a 0.5-2keV flux level of 10-14erg/cm2/s. The
distribution of best-fitting spectral slopes of the hard sources
suggests that a typical ROSAT hard source in our survey has a spectral
slope α∼0. The hard sources have a steep number flux relation
(dN/dSµS-γ with a best-fitting value of
γ=2.72±0.12) and make up about 15 per cent of all 0.5-2keV
sources with S>10-14erg/cm2/s. If their N(S) continues to fainter
fluxes, the hard sources will comprise ∼40 per cent of sources with
5x10-15<S<10-14erg/cm2/s. The population of hard sources can
therefore account for the harder average spectra of ROSAT sources with
S<10-14erg/cm2/s. They probably make a strong contribution to the
X-ray background at faint fluxes and could be the solution to the
X-ray background spectral paradox.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 127 147 Hard source catalogue
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See also:
IX/30 : Second ROSAT PSPC Catalog (ROSAT, 2000)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [RXJ]
4- 21 A18 --- RXJ Source name based on J2000 coordinates of
ROSAT source from PSS (1)
23- 33 A11 --- ROR ROSAT observation in which source was
detected
35- 38 F4.1 ks ExpTime ROSAT PSPC exposure time after good time
screening
40- 43 F4.1 arcmin OffAxis Off-axis angle of source
45- 48 F4.1 arcsec ePos Positional uncertainty of source from PSS
50- 53 F4.1 --- sigma PSS significance of source above background
level
55- 58 F4.1 --- PSF Spread function to the source radial profile
in 5" bins out to 1', from a fit of the
model PSPC point
60- 61 I2 arcsec Rad Source circle radius for extraction of the
three-colour spectrum
63- 65 I3 ct C1 Number of counts in PSPC channels 11-41
(0.1-0.4keV) within the source circle
67- 69 I3 ct C2 Number of counts in PSPC channels 52-90
(0.5-0.9keV] within the source circle
71- 73 I3 ct C3 Number of counts in PSPC channels 91-201
(0.9-2.0 keV) within the source circle
75- 79 F5.1 ct B1 Expected number of background counts in PSPC
channels 11-41 within the source circle
81- 85 F5.1 ct B2 Expected number of background counts in PSPC
channels 52-90 within the source circle
87- 90 F4.1 ct B3 Expected number of background counts in PSPC
channels 91-201 within the source circle
92- 96 F5.2 --- alpha Fitted power-law spectral slope
98-101 F4.2 --- E_alpha 68% uncertainty in alpha (upper limit)
103-106 F4.2 --- e_alpha 68% uncertainty in alpha (lower limit)
108-111 F4.2 --- Prob Probability of source having spectral slope
alpha<(harder than) 0.5
113-117 F5.2 10-17W/m2 S0.5-2 0.5-2keV flux (3)
119-121 F3.1 10-17W/m2 E_S0.5-2 68% uncertainty on S0.5-2 (upper limit) (3)
123-125 F3.1 10-17W/m2 e_S0.5-2 68% uncertainty on S0.5-2 (lower limit) (3)
127 A1 --- Flag [SI] Optical counterpart flag (2)
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Note (1): Sources identified as [PMC2000] RX JHHMMSS.ss+DDMMSS.s in Simbad
Note (2): Optical counterpart flag as follows:
S = means spectroscopic sample
I = means imaging sample
Note (3): in 10-14erg/cm2/s
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History:
From electronic version of the journal and prepared via OCR at CDS.
(End) James Marcout, Patricia Bauer [CDS] 28-Mar-2001