J/A+A/553/A12 XMM-Newton SSC survey of Galactic Plane (Nebot Gomez-Moran+, 2013)
The XMM-Newton SSC survey of the Galactic Plane.
Nebot Gomez-Moran A., Motch C., Barcons X., Carrera F.J., Ceballos M.T.,
Cropper M., Grosso N., Guillout P., Herent O., Mateos S., Michel L.,
Osborne J.P., Pakull M., Pineau F.-X., Pye J.P., Roberts T.P., Rosen S.R.,
Schwope A.D., Watson M.G., Webb N.
<Astron. Astrophys. 553, A12 (2013)>
=2013A&A...553A..12N 2013A&A...553A..12N
ADC_Keywords: Surveys - X-ray sources ; Cross identifications ; Photometry
Keywords: X-rays: binaries - X-rays: stars - surveys
Abstract:
Many different classes of X-ray sources contribute to the Galactic
landscape at high energies. Although the nature of the most luminous
X-ray emitters is now fairly well understood, the population of
low-to-medium X-ray luminosity (LX=1027-34erg/s) sources remains
much less studied, our knowledge being mostly based on the observation
of local members. The advent of wide field and high sensitivity X-ray
telescopes such as XMM-Newton now offers the opportunity to observe
this low-to-medium LX population at large distances. We report on the
results of a Galactic plane survey conducted by the XMM-Newton Survey
Science Centre (SSC). Beyond its astrophysical goals, this survey aims
at gathering a representative sample of identified X-ray sources at
low latitude that can be used later on to statistically identify the
rest of the serendipitous sources discovered in the Milky Way. The
survey is based on 26 XMM-Newton observations, obtained at
|b|<20°, distributed over a large range in Galactic longitudes and
covering a summed area of 4deg2. The flux limit of our survey is
2x10-15erg/cm2/s in the soft (0.5-2keV) band and
1x10-14erg/cm2/s in the hard (2-12keV) band. We detect a total of
1319 individual X-ray sources. Using optical follow-up observations
supplemented by cross-correlation with a large range of
multi-wavelength archival catalogues we identify 316 X-ray sources.
This constitutes the largest group of spectroscopically identified low
latitude X-ray sources at this flux level. The majority of the
identified X-ray sources are active coronae with spectral types in the
range A-M at maximum distances of ∼1kpc. The number of identified
active stars increases towards late spectral types, reaching a maximum
at K. Using infrared colours we classify 18% of the stars as giants.
The observed distributions of FX/FV, X-ray and infrared colours
indicates that our sample is dominated by a young (100Myr) to
intermediate (600Myr) age population with a small contribution of
close main sequence or evolved binaries. We find other interesting
objects such as cataclysmic variables (d∼0.6-2kpc), low luminosity
high mass stars (likely belonging to the class of γ-Cas-like
systems, d∼1.5-7kpc), T Tauri and Herbig-Ae stars. A handful of
extragalactic sources located in the highest Galactic latitude fields
could be optically identified. For the 20 fields observed with the
EPIC pn camera, we have constructed logN(>S)-logS curves in the soft
and hard bands. In the soft band, the majority of the sources are
positively identified with active coronae and the fraction of stars
increases by about one order of magnitude from b=60° to b=0°
at an X-ray flux of 2x10-14erg/cm2/s. The hard band is dominated
by extragalactic sources, but there is a small contribution from a
hard Galactic population formed by CVs, HMXB candidates or
γ-Cas-like systems and by some active coronae that are also
detected in the soft band. At b=0° the surface density of hard
sources brighter than 1x10-13erg/cm2/s steeply increases by one
order of magnitude from l=20° to the Galactic centre region
(l=0.9°).
Description:
Tables 8-33 list the X-ray sources detected in the 26 different fields
observed in this study, with their X-ray parameters and optical and
infrared counterparts.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 89 26 Target fields and source classification
table8.dat 149 27 X-ray parameters for detected sources in
field 3C 449
table9.dat 149 28 X-ray parameters for detected sources in
field 3C 436
table10.dat 149 23 X-ray parameters for detected sources in
field AX J2019+112
table11.dat 149 22 X-ray parameters for detected sources in
field G21.5-09 offset 2
table12.dat 149 32 X-ray parameters for detected sources in
field GC 2
table13.dat 149 39 X-ray parameters for detected sources in
field GRB001025
table14.dat 149 39 X-ray parameters for detected sources in
field GRO J1655-40
table15.dat 149 19 X-ray parameters for detected sources in
field HT Cas
table16.dat 149 30 X-ray parameters for detected sources in
field LHB-3
table17.dat 152 65 X-ray parameters for detected sources in
field PKS 0745-19-offset
table18.dat 149 21 X-ray parameters for detected sources in
field PSR J0117+5914
table19.dat 149 25 X-ray parameters for detected sources in
field Ridge 1
table20.dat 149 21 X-ray parameters for detected sources in
field Ridge 2
table21.dat 149 21 X-ray parameters for detected sources in
field Ridge 3
table22.dat 148 8 X-ray parameters for detected sources in
field Ridge 4
table23.dat 149 18 X-ray parameters for detected sources in
field Saturn
table24.dat 149 53 X-ray parameters for detected sources in
field WR 110
table25.dat 149 31 X-ray parameters for detected sources in
field Z And
table26.dat 149 16 X-ray parameters for detected sources in
field GRB010220
table27.dat 151 38 X-ray parameters for detected sources in
field RX J0925.7-4758
table28.dat 149 22 X-ray parameters for detected sources in
field AR Lac
table29.dat 149 38 X-ray parameters for detected sources in
field Geminga
table30.dat 149 18 X-ray parameters for detected sources in
field PSR 0656+14
table31.dat 149 30 X-ray parameters for detected sources in
field RX J0002+6246
table32.dat 152 13 X-ray parameters for detected sources in
field SS Cyg
table33.dat 149 42 X-ray parameters for detected sources in
field PSR J2043+2740
--------------------------------------------------------------------------------
See also:
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- n_Seq [bf] Sample:
b = Optically bright sample (Rlim∼17),
f = Optically faint sample (Rlim∼21)
3- 4 I2 --- Seq Sequential field number
6- 23 A18 --- Field Field designation
25- 29 F5.1 deg GLON Galactic longitude
31- 35 F5.1 deg GLAT Galactic latitude
37- 43 E7.2 cm-2 NH Calculated hydrogen column density (1)
45- 54 A10 --- ObsID XMM Observation ID
56- 57 I2 ks Texp EPIC-pn exposure time
58 A1 --- n_Texp [M] M if EPIC-MOS exposure time
60- 61 I2 --- Ntot Total number of 2XMMi-DR3 sources detected (2)
63- 64 I2 --- AC Number of identified active coronae (2)
66- 67 I2 % AC% Percentage of identified active coronae (2)
69 I1 --- HMBX Number of identified High-mass X-ray binaries (2)
71 I1 --- pMS Number of identified pre-main sequence stars (2)
73- 74 I2 --- EG Number of identified extragalactic sources (2)
76- 77 I2 --- un Number of unidentified sources (2)
79- 89 A11 --- File Name of the file with X-ray observations
--------------------------------------------------------------------------------
Note (1): We used the Schlegel et al. (1998ApJ...500..525S 1998ApJ...500..525S) maps to estimate
the color excess E(B-V) at each Galactic position. We transformed into
optical extinction AV using the relation from Savage & Mathis
(1979, ARA&A, 17,73), and we used the empirical relation from Predehl &
Schmitt (1995A&A...293..889P 1995A&A...293..889P) to calculate NH. We note that for very low
Galactic latitudes (|b|<5°) values could be wrong, but we use the values
for orientative purposes.
Note (2): Sums for all bright sample, faint sample and total:
----------------------------------------------------------------------------
Ntot AC HMXB Pre-MS EG unID
----------------------------------------------------------------------------
All b : 696 125 (17.9%) 2 (0.3%) 2 (0.3%) 8 (1.1%) 560 (80.3%)
All f : 430 110 (25.8%) 1 (0.2%) 2 (0.4%) 25 (5.8%) 291 (67.7%)
Total : 1126 235 3 4 33 851
----------------------------------------------------------------------------
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table[89].dat table??.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2XMM 2XMM name of XMM-DR3 source (JHHMMSS.s+DDMMSS)
18- 21 F4.2 arcsec r90 90% confidence error radius
23- 27 F5.1 ct/ks CRpn1 ? Count rate in energy band 1 [0.5-2.0keV]
29- 32 F4.1 ct/ks e_CRpn1 ? rms uncertainty on CRpnB1
34- 38 F5.1 ct/ks CRpn2 ? Count rate in energy band 2 [2.0-12.0keV]
40- 42 F3.1 ct/ks e_CRpn2 ? rms uncertainty on CRpnB2
44- 59 A16 --- 2MASS 2MASS association name (HHMMSSss+DDMMSSs)
61- 64 F4.1 arcsec dx2 ? Distance between X-ray and 2MASS source
66- 69 F4.2 --- Pid2 ? Probability of 2MASS identification
71- 75 F5.2 mag Ksmag ? 2MASS Ks magnitude
77- 86 A10 --- GSC GSC association name (AANNNNNNNN)
88- 91 F4.1 arcsec dxg ? Distance between X-ray and GSC source
93- 96 F4.2 --- Pidg ? Probability of GSC identification
98-102 F5.2 mag Vmag ? GSC V magnitude
104-115 A12 --- USNO USNO-B1.0 association name (NNNN-NNNNNNN)
117-120 F4.1 arcsec dxu ? Distance between X-ray and USNO source
122-125 F4.2 --- Pidu ? Probability of USNO identification
127-131 F5.2 mag Rmag ? USNO-B1.0 R2 magnitude
133-136 A4 --- Class Classification of the source (1)
141-145 A5 --- SpType Spectral type (1)
148-152 A5 --- n_SpType [sp image] Note (2)
--------------------------------------------------------------------------------
Note (1): either MK spectral class (the luminosity class corresponds to
that derived in Section 6.1), or classification of object:
AGN = Active Galaxy Nucleus
Star = active coronae
EG = extragalactic sources
CV = cataclysmic variables
TTS = T Tauri stars
HMXB = high mass X-ray binaries.
The luminosity class corresponds to that derived in Section 6.1.
Note (2): How the source was identified, as follows:
sp = spectroscopic identified sources
s = objects with SIMBAD identification
image = sources found to be extended in the optical images
--------------------------------------------------------------------------------
Acknowledgements:
Ada Nebot, ada.nebot(at)astro.unistra.fr
(End) Patricia Vannier [CDS] 25-Mar-2013