J/A+A/548/A99 XMM-Newton Slew Survey in 2-10keV (Warwick+, 2012)
The XMM-Newton Slew Survey in the 2-10 keV band.
Warwick R.S., Saxton R.D., Read A.M.
<Astron. Astrophys. 548, A99 (2012)>
=2012A&A...548A..99W 2012A&A...548A..99W
ADC_Keywords: Surveys ; Galaxy catalogs ; Active gal. nuclei ; X-ray sources
Keywords: surveys - X-rays: general - galaxies: active
Abstract:
The on-going XMM-Newton Slew Survey (XSS) provides coverage of a
significant fraction of the sky in a broad X-ray bandpass. Although
shallow by contemporary standards, in the "classical" 2-10keV band
of X-ray astronomy, the XSS provides significantly better sensitivity
than any currently available all-sky survey.
We investigate the source content of the XSS, focussing on detections
in the hard 2-10keV band down to a very low threshold (≥4counts net
of background). At the faint end, the survey reaches a flux
sensitivity of roughly 3x10-12erg/cm2/s (2-10keV).
Our starting point was a sample of 487 sources detected in the XSS (up
to and including release XMMSL1d2) at high galactic latitude in the
hard band. Through cross-correlation with published source catalogues
from surveys spanning the electromagnetic spectrum from radio through
to gamma-rays, we find that 45% of the sources have likely
identifications with normal/active galaxies. A further 18% are
associated with other classes of X-ray object (nearby coronally active
stars, accreting binaries, clusters of galaxies), leaving 37% of the
XSS sources with no current identification. We go on to define an XSS
extragalactic sample comprised of 219 galaxies and active galaxies
selected in the XSS hard band. We investigate the properties of this
extragalactic sample including its X-ray logN-logS distribution.
We find that in the low-count limit, the XSS is, as expected, strongly
affected by Eddington bias. There is also a very strong bias in the
XSS against the detection of extended sources, most notably clusters
of galaxies. A significant fraction of the detections at and around
the low-count limit may be spurious. Nevertheless, it is possible to
use the XSS to extract a reasonably robust sample of extragalactic
sources, excluding galaxy clusters. The differential logN-logS
relation of these extragalactic sources matches very well to the
HEAO-1 A2 all-sky survey measurements at bright fluxes and to the 2XMM
source counts at the faint end.
The substantial sky coverage afforded by the XSS makes this survey a
valuable resource for studying X-ray bright source samples, including
those selected specifically in the hard 2-10keV band.
Description:
Details of the sources which comprise the hard-band selected XSS
extragalactic sample are given in the Table. The table provides the
following information for each source: the XSS name; whether the
source was also detected in the XSS soft band (1=yes, 0=no); the XSS
hard band (2-10keV) flux and error on the flux (in units of
10-11ergs/cm2/s) ; the RA and Dec of the proposed counterpart; the
name of the counterpart; the type of the counterpart; the redshift (if
known).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 126 219 XSS extragalactic sample parameters
--------------------------------------------------------------------------------
See also:
B/xmm : XMM-Newton Observation Log (XMM-Newton SOC, 2012)
J/A+A/480/611 : XMM-Newton Slew Survey catalogue, XMMSL1 (Saxton+, 2008)
J/MNRAS/412/1853 : XMM Slew Survey unidentified X-ray sources (Starling+, 2011)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- --- [XMMSL1]
8- 23 A16 --- XMMSL1 SLEW XSS identifier (JHHMMSS.s+DDMMSS)
25 I1 --- Soft [0/1] Detected in soft band? (1=yes, 0=no)
27- 45 F19.17 10-14W/m2 Flux Flux in 2-10keV bands (10-11erg/cm2/s)
47- 65 F19.17 10-14W/m2 e_Flux Error on Flux
67- 75 F9.5 deg RAdeg Right ascension of counterpart (J2000)
77- 85 F9.5 deg DEdeg Declination of counterpart (J2000)
87-110 A24 --- ID Name of counterpart
112-116 A5 --- Type Type of counterpart (1)
119-126 F8.5 --- z ?=-9 Redshift of counterpart
--------------------------------------------------------------------------------
Note (1): Classes(population) are: BLLac(28), Galaxy(38), LINER(2), QSO(35),
RG(5), Sy1(60), Sy1.2(8), Sy1.5(11), Sy1.9(3), Sy2(11), UVX(18).
"RG" are red galaxies/QSOs, and "UVX" are sources initially
categorized as Galaxies which ere switched to AGN on the basis of
their UV to near-IR colour.
--------------------------------------------------------------------------------
Acknowledgements:
A.M. Read, amr30(at)le.ac.uk
(End) Patricia Vannier [CDS] 19-Oct-2012