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ALFPERXMM - Alpha Per Open Cluster XMM-Newton X-Ray Source Catalog

HEASARC
Archive

Overview

This table contains results from the analysis of an archival XMM-Newton observation of part of the Alpha Persei open cluster. The authors detected 102 X-ray sources in the energy band from 0.3 to 8.0 keV, of which 39 of them are associated with the cluster as evidenced by their appropriate magnitudes and colors from Two Micron All Sky Survey (2MASS) photometry. In the reference paper, the authors extend the X-ray luminosity distribution (XLD) of the Alpha Persei cluster for M dwarfs, to add to the XLD found for hotter dwarfs from spatially extensive surveys of the whole cluster by ROSAT. Some of the hotter stars are identified as a background, possible slightly older group of stars at a distance of approximately 500 pc.

Alpha Per is a young open cluster, found to be 50 Myr old from its upper main sequence turnoff morphology (Meynet et al. 1993, A&AS, 98, 477). More recently, Stauffer et al. (1999, ApJ, 527, 219) have found an age of 90 Myr from the low mass lithium depletion boundary. In addition to being relatively nearby (170 pc; Randich et al. 1996, A&A, 305, 785), the Alpha Per cluster is also lightly reddened (E(B - V ) = 0.09 mag; Meynet et al. 1993), making the data interpretation relatively robust.

A fraction of the Alpha Per cluster was observed by XMM-Newton as part of the Mission Scientist Guaranteed Time (Pallavicini et al., 2004, MmSAI, 75, 434). A 60-ks observation was obtained on 2000 September 5 using the EPIC MOS and PN cameras on board XMM-Newton with a pointing centered at RA: 3h 26m 16s and Dec: 48o 50m 29s (J2000.0).


Catalog Bibcode

2013AJ....145..143P

References

XMM-Newton observation of the {alpha} Persei cluster.
    Pillitteri I., Evans N.R., Wolk S.J., Bruck Syal M.
   <Astron. J., 145, 143 (2013)>
   =2013AJ....145..143P

Provenance

This table was created by the HEASARC in June 2014 based on CDS Catalog J/AJ/145/143 files table1.dat and table2.dat.

Parameters

Source_Number
A unique sequential identification number for each X-ray source, in order of increasing J2000.0 Declination.

Name
The X-ray source designation registered with the Dictionary of Nomenclature of Celestial Objects, viz., '[PEW2013' nnn', where the prefix refers to the reference paper (Pillitteri, Evans, Wolk... 2013) and nnn is the source number.

RA
The Right Ascension of the Chandra source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 seconds of time in the original table.

Dec
The Declination of the Chandra source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the Chandra source.

BII
The Galactic Latitude of the Chandra source.

Off_Axis
The off-axis angle of the X-ray source, in arcminutes, i.e., the angular separation between the X-ray source and the aim point (specified in the Overview).

Significance
The significance of the X-ray source in terms of the background rms.

Count_Rate
The X-ray source count rate, in counts per second (converted by the HEASARC from the ct/ks units in the original table), for the summed MOS and PN detectors, assuming a PN-MOS conversion factor of 3.1.

Exposure
The effective exposure time, in seconds (converted by the HEASARC from the ks units in the original table), for the summed MOS and PN detectors, assuming a PN-MOS conversion factor of 3.1.

TwoMASS_Name
The 2MASS identifier, viz., '2MASS JHHMMSSss+DDMMSSs', of the matching infrared source. A match radius of 5 arcseconds was used.

TwoMASS_RA
The Right Ascension of the 2MASS matching source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 seconds of time in the original table.

TwoMASS_Dec
The Declination of the 2MASS matching source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original table.

Jmag
The 2MASS J band magnitude of the 2MASS matching source (from Cutri et al. 2003, CDS Catalog II/246).

Hmag
The 2MASS H band magnitude of the 2MASS matching source (from Cutri et al. 2003, CDS Catalog II/246).

Ks_Mag
The 2MASS Ks band magnitude of the 2MASS matching source (from Cutri et al. 2003, CDS Catalog II/246).

kT
The fitted temperature to the X-ray source spectrum, in keV.

Log_EM
The logarithm of the fitted emission measure to the X-ray source spectrum, in cm-. The X-ray emission measures and luminosities have been computed assuming that the source is at the 170 pc distance of the Alpha Per cluster.

Log_Fx
The logarithm of the flux of the X-ray source in the 0.3-8.0 keV energy band, in erg s-1 cm-2.

Log_Lx
The logarithm of the luminosity of the X-ray source in the 0.3-8.0 keV energy band, in erg s-1. The X-ray emission measures and luminosities have been computed assuming that the source is at the 170 pc distance of the Alpha Per cluster.


Contact Person

Questions regarding the ALFPERXMM database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 26-Jun-2014