H Persei Chandra X-Ray Point Source Catalog

H Persei Chandra X-Ray Point Source Catalog HPERSEICXO ivo://nasa.heasarc/hperseicxo NASA/GSFC HEASARC Currie et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains some of the results from a Chandra/ACIS-I observations of the massive ~ 13-14 Myr-old cluster, h Persei, part of the famous Double Cluster (h and Chi Persei) in Perseus. Combining the list of 330 Chandra-detected sources with new optical/IR photometry and optical spectroscopy reveals ~ 165 X-ray bright stars with V <~ 23. Roughly 142 have optical magnitudes and colors consistent with cluster membership. The observed distribution of X-ray luminosity Lx peaks at Lx ~ 1030.3 erg s-1 and likely traces the bright edge of a far larger population of ~ 0.4-2 Msun X-ray active stars. From a short list of X-ray active stars with IRAC 8-micron excess from warm, terrestrial zone dust, the authors derive a maximum X-ray flux incident on forming terrestrial planets. Although there is no correlation between X-ray activity and IRAC excess, the fractional X-ray luminosity correlates with optical colors and spectral type. By comparing the distribution of Lx/Lstar versus spectral type and (V-I) in h Per with results for other 1-100 Myr-old clusters, the authors show that stars slightly more massive than the Sun (>~ 1.5 Msun) fall out of X-ray saturation by ~ 10-15 Myr. Changes in stellar structure for >~ 1.5 Msun stars likely play an important role in this decline of X-ray emission. Chandra observations of h Persei were taken with a 41.1 ks exposure on 2004 December 2, (Obs. ID 5407; Sequence Number 200341) with the ACIS detector (chips 0, 1, 2, 3, 6, and 7). The data were obtained in dithered, timed mode, with a frametime of 3.2 s. On-board event rejection and event telemetry was in the VFAINT mode. The field was centered on RA(2000) = 2h19m00s, Dec(2000) = 57d07'12", close to the center of h Persei from Bragg & Kenyon (2005, AJ, 130, 134) (RA(2000) = 2h18m56.4s, Dec(2000) = 57d08'25") and observed at a roll angle of 229 degrees. The data were not registered to an astrometric reference frame (e.g., Two Micron All Sky Survey, 2MASS). The ACIS-I field covers a 17' x 17' area. This table was created by the HEASARC in March 2009 based on the electronic versions of Tables 1 and 2 from the paper which were obtained from the Astronomical Journal web site. This is a service provided by NASA HEASARC . 2009AJ....137.3210C https://heasarc.gsfc.nasa.gov/W3Browse/all/hperseicxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=hperseicxo& GET text/xml 180 99999 true 35.0381 56.8501 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=hperseicxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_hperseicxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public hperseicxo H Persei Chandra X-Ray Point 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 counts Net Counts in 95% Encircled Energy Radius ct phot;em.X-ray double nullable flux Sherpa Unabsorbed X-Ray Flux erg/s/cm^2 phot.flux;em.X-ray double nullable log_lx Logarithm of X-Ray Luminosity (in erg/s) log(erg/s) phys.luminosity;em.X-ray double nullable jmag 2MASS J-Band Magnitude mag phot.mag;em.IR.J double nullable num_spect_type Number Indicates Spectral Type meta.code;src.spType 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 vmag_error The 1-Sigma Uncertainty in V Magnitude mag stat.error;phot.mag;em.opt.V double nullable bii Galactic Latitude degree pos.galactic.lat double nullable irac_4p5_um_mag Spitzer/IRAC 4.5-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable apec_kt_error The 1-Sigma Uncertainty in kT keV stat.error;phys.temperature double nullable class Browse Object Classification src.class short nullable imag The I-Band Magnitude mag phot.mag;em.opt.I double nullable hr2 Second Hardness Ratio phot.count;arith.ratio;em.X-ray double nullable hr3 Third Hardness Ratio phot.count;arith.ratio;em.X-ray double nullable irac_8p0_um_mag Spitzer/IRAC 8.0-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable hmag 2MASS H-Band Magnitude mag phot.mag;em.IR.H double nullable irac_3p6_um_mag Spitzer/IRAC 3.6-micron Band Magnitude mag phot.mag;em.IR.3-4um double nullable apec_kt Sherpa X-Ray Temperature (keV) keV phys.temperature double nullable counts_error Uncertainty in Net Counts ct stat.error;phot;em.X-ray double nullable num_spect_type_error The 1-Sigma Uncertainty in Numerical Spectral Type stat.error;src.spType double nullable source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable reduced_chi_squared Reduced Chi^2 of Sherpa Fit stat.fit.chi2 double nullable absorbed_flux Sherpa Absorbed X-Ray Flux erg/s/cm^2 phot.flux;em.X-ray double nullable ks_mag 2MASS K_S-Band Magnitude mag phot.mag;em.IR.K double nullable ra_optical Optical Right Ascension degree meta.id.cross;pos.eq.ra double nullable irac_5p8_um_mag Spitzer/IRAC 5.8-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable vmag V-Band Magnitude mag phot.mag;em.opt.V double nullable lii Galactic Longitude degree pos.galactic.lon double nullable raw_counts Raw Counts in 95% Encircled Energy Radius ct phot;em.X-ray short nullable imag_error The 1-Sigma Uncertainty in I Magnitude mag stat.error;phot.mag;em.opt.I double nullable dec_optical Optical Declination degree meta.id.cross;pos.eq.dec double nullable hr1 First Hardness Ratio phot.count;arith.ratio;em.X-ray double nullable