ALFPERXMM ivo://nasa.heasarc/alfperxmm NASA/GSFC HEASARC Pillitteri et al. 2026-10-02 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source 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: 3<sup>h</sup> 26<sup>m</sup> 16<sup>s</sup> and Dec: 48<sup>o</sup> 50<sup>m</sup> 29<sup>s</sup> (J2000.0). This table was created by the HEASARC in June 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/145/143">CDS Catalog J/AJ/145/143</a> files table1.dat and table2.dat. This is a service provided by NASA HEASARC . 2013AJ....145..143P https://heasarc.gsfc.nasa.gov/W3Browse/all/alfperxmm.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=alfperxmm& GET text/xml 180 99999 true 51.65791667 48.62469444 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=alfperxmm GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_alfperxmm&Action=More+Options&Action=Parameter+Search&ConeAdd=1 XMM-NEWTON 0.0166666666666667 Infrared X-ray public alfperxmm Alpha Per Open Cluster XMM-Newton X-Ray Source Catalog name Source Designation meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable off_axis Offset Axis arcmin instr.offset double nullable count_rate X-Ray Source Count Rate ct/s phot.count;em.X-ray double nullable significance Significance stat.likelihood;phot.count;em.X-ray double nullable log_lx Logarithm of X-Ray Luminosity log(erg/s) phys.luminosity;em.X-ray double nullable jmag 2MASS J Band Magnitude (from Cat. II/246) mag phot.mag;em.IR.J double nullable hmag 2MASS H Band Magnitude (from Cat. II/246) mag phot.mag;em.IR.H double nullable ks_mag 2MASS K_s Band Magnitude (from Cat. II/246) mag phot.mag;em.IR.K double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable bii Galactic Latitude degree pos.galactic.lat double nullable log_em Fitted Emission Measure cm^-3 phys.emissMeasure double nullable twomass_dec Declination of 2MASS Matching Source degree pos.eq.dec;em.IR double nullable twomass_ra Right Ascension of 2MASS Matching Source degree pos.eq.ra;em.IR double nullable exposure Effective Exposure Time s time.duration;obs.exposure double nullable source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable lii Galactic Longitude degree pos.galactic.lon double nullable log_fx Logarithm of X-Ray Flux log(erg/s/cm^2) phot.flux;em.X-ray double nullable kt Fitted Temperature keV phys.temperature double nullable twomass_name 2MASS Identifier (2MASS JHHMMSSss+DDMMSSs) of Matching Source meta.id.cross char nullable