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NGC2516XMM - NGC 2516 Cluster XMM-Newton X-Ray Point Source Catalog |
HEASARC Archive |
NGC 2516 has been observed several times with XMM-Newton during the first two years of satellite operations for calibration purposes. The observations used in this analysis span a period of 19 months with exposure times between 10 and 20 ks. All of these observations have been performed with the thick filter. In the combined EPIC datasets the authors detected 431 X-ray sources with a significance level greater than 5.0 sigma, which should lead statistically to at most one spurious source in the field of view.
Deep X-ray survey of the young open cluster NGC 2516 with XMM-Newton. Pillitteri I., Micela G., Damiani F., Sciortino S. <Astron. Astrophys., 450, 993-1004 (2006)> =2006A&A...450..993P
Source_Number
A running source number in order of increasing J2000.0
Declination, i.e., source number 1 is the furthest south, which uniquely
identifies the X-ray source.
Name
The name of the X-ray source using the '[PMD2006]' prefix (for
Pillitteri, Micela, Damiani 2006), together with the X-ray source number, as
recommended by the CDS Dictionary of Nomenclature of Celestial Objects.
RA
The Right Ascension of the X-ray source in the selected equinox. This
was given in J2000.0 coordinates to a precision of 0.01 seconds of time in
the original table.
Dec
The Declination of the X-ray source in the selected equinox. This was
given in J2000.0 coordinates to a precision of 0.01 arcseconds in the original
table.
LII
The Galactic Longitude of the X-ray source.
BII
The Galactic Latitude of the X-ray source.
Count_Rate
The count rate of the X-ray source, in MOS1-equivalent counts per
second, as described in Section 2 of the reference paper.
Count_Rate_Error
The RMS uncertainty in the X-ray source count rate, in
MOS1-equivalent counts per second.
SNR
The detection significance of the X-ray source, in units of the
background mean standard deviation.
Exposure
The exposure time, in seconds, that was used to calculate the
count rate of the X-ray source, as obtained from the exposure maps, and thus
taking into account any spatial non-uniformities due to vignetting, RGS
grating obscuration, chip geometry etc.
Off_Axis
The off-axis distance of the X-ray source, in arcminutes
(presumably from the center of the combined EPIC X-ray image shown in Figure 1
of the reference paper).
Source_Flag
A few X-ray sources do not have counterparts in optical or
infrared bands. After having searched for optical counterparts of the X-ray
sources in GSC-II, 2MASS and DENIS and the complete catalog of Jeffries et al.
(2001, A&A, 375, 863), 49 sources were left without optical/infrared known
counterparts, and have been marked with a 'U' for their source_flag value.
Jth_Number
The identification number of the optical counterpart to the X-ray source,
from an optical catalog built from the list of Jeffries et al. (2001, A&A,
375, 863), and (for 42 cluster stars brighter than V = 9.7) from Dachs and
Kabus (1989, A&AS, 78, 25), referred to as the JTH number in the reference
paper. The authors matched the positions of X-ray sources with the optical
coordinates in the composite catalog. No significant systematic offsets were
found between optical and X-ray astrometry. By studying the distribution of
the offsets of matched sources, they chose a maximum identification radius of
7 arcseconds, where the number of observed matches is similar to the number
of expected chance identifications.
Offset
The matching distance between the X-ray source and its proposed
optical counterpart, in arcseconds. Five X-ray sources were doubly matched
with close pairs in the optical catalog and are thus listed twice, once
for each possible optical counterpart.
Vmag
The V magnitude of the optical counterpart to the X-ray source.
BV_Color
The B-V color index of the optical counterpart to the X-ray source.
VI_Color
The V-I color index of the optical counterpart to the X-ray source.
Flux
The X-ray flux in the 0.3 - 7.9 keV band, in erg/s/cm2. The authors have
estimated a conversion factor (CF) in the 0.3 - 7.9 keV band between count
rates (in units of the MOS 1 instrument, as obtained by the detection code)
and their unabsorbed fluxes, derived by the spectral analysis of the bright
X-ray sources of the cluster (see Sect. 2.3 of the reference paper); the
resulting CF, used for all the cluster X-ray sources, was 9.5 x 10-12 erg
ct-1 cm-2. The 3-sigma uncertainty in the CF takes into account the
dependence on the spectrum hardness and is +/- 14%; it would systematically
shift fluxes and luminosities by +0.06 and -0.07 dex, respectively.
Flux_Error
The RMS uncertainty in the X-ray flux in the 0.3 - 7.9 keV band, in
erg/s/cm2.
Log_Lx
The logarithm of the X-ray luminosity in the 0.3 - 7.9 keV band, in erg/s,
calculated from the X-ray flux assuming a distance to the cluster of 387 pc,
as adopted by Jeffries et al. (1997) and Damiani et al. (2003). This distance
is slightly larger than the Hipparcos satellite estimate of 346 pc; assuming
this latter value, the luminosities would decrease by -0.05 dex.
Log_Lx_Neg_Err
The negative error in the logarithm of the X-ray luminosity in the 0.3 - 7.9
keV band in erg/s.
Log_Lx_Pos_Err
The positive error in the logarithm of the X-ray luminosity in the 0.3 - 7.9
keV band in erg/s.
Log_Lbol
The logarithm of the bolometric luminosity of the optical counterpart to the
X-ray source, in erg/s.
Log_Lx_Lbol
The bolometric-to-X-ray luminosity ratio of the source.