RCW 108 Star Formation Region Chandra X-Ray Point Source Catalog

RCW 108 Star Formation Region Chandra X-Ray Point Source Catalog RCW108CXO ivo://nasa.heasarc/rcw108cxo NASA/GSFC HEASARC Wolk 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 of an approximately 90 ks Chandra observation of a complex region that hosts multiple sites of recent and active star formation in ARA OB1a. The field is centered on the embedded cluster RCW 108-IR and includes a large portion of the open cluster NGC 6193. The authors detected over 420 X-ray sources in the field and combined these data with deep near-IR, Spitzer/IRAC and Midcourse Space Experiment (MSX) mid-IR data. They find that about 360 of the X-ray sources have near-IR counterparts. They divide the region into five parts based on the X-ray point source characteristics and extended 8 micron emission. The most clearly defined regions are the central region, identified by embedded sources with high luminosities in the both the near-IR and X-ray as well as high X-ray temperatures (~3 keV), and the eastern region, identified by low extinction and ~1 keV X-ray temperatures. Other regions, identified by their directional relationship to RCW 108-IR, are less uniform, representing combinations of the first two regions, independent star formation epochs, or both. The cluster members range in X-ray luminosity from 1029 to 1033 erg s-1. Over 18% of the cluster members with over 100 counts exhibit flares. All sources with over 350 counts are variable. Overall about 10% (16% in RCW 108-IR) appear to have optically thick disks as derived from their position in the (J - H), (H - K) diagram. The disk fraction becomes much higher when IRAC data are employed. The largest fraction of X-ray sources is best described as possessing some disk material via a more detailed extinction fitting. The authors fit the bulk of the X-ray spectra as absorbed Raymond-Smith-type plasmas, and find that the column to the RCW 108-IR members varies from 1021 to 1023 cm-2. They find that the field contains 41 candidate O or B stars, and estimate that the total number of pre-main-sequence stars in the field is about 1600 +/- 200. Approximately 800 are confined to the 3' (~1.1 pc) central region. The field was observed by Chandra on 2004 October 25 starting at 02:37 UT for 92.2 ks of total time and 88.8 ks of so-called "good-time" (ObsId 4503). The ACIS was used in the nominal imaging array (chips I0-I3) which provides a field of view of approximately 17' by 17' (~6.5 pc on a side). The aimpoint was at RA, Dec = 16:39:58.7, -48:51:54.4 (J2000.0). In addition, the S2 and S3 chips were on and located over IRAS 16379-4856. About 20 point sources were detected associated with this object; however, the analysis of these data is not presented here because they are far off-axis. This table was created by the HEASARC in June 2008 based on electronic versions of Tables 1, 2, 5, 7, 10 and 11 from the reference paper which were obtained from the Astronomical Journal web site. This is a service provided by NASA HEASARC . 2008AJ....135..693W https://heasarc.gsfc.nasa.gov/W3Browse/all/rcw108cxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=rcw108cxo& GET text/xml 180 99999 true 249.99125 -49.03825556 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=rcw108cxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_rcw108cxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public rcw108cxo RCW 108 Star Formation Region Chandra X-Ray Point Source Catalog name Official IAU-Style Source Designation (CXOWSB JHHMMSS.S-DDMMSS) 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 ct phot;em.X-ray double nullable significance Source Significance stat.fit.goodness double nullable flux Unabsorbed Flux (erg/s/cm^2) erg/s/cm^2 phot.flux;em.X-ray double nullable ra_nir_j2000 J2000 Right Ascension of Near-Infrared Source pos.eq.ra char nullable dec_nir_j2000 J2000 Declination of Near-Infrared Source pos.eq.dec char nullable jmag The J Band Magnitude mag phot.mag;em.IR.J double nullable nir_flags Flags Indicate NIR Data from Either VLT, NTT, or 2MASS (=> JHK Quality Flags) meta.code;src char nullable bii Galactic Latitude degree pos.galactic.lat double nullable hmag The H Band Magnitude mag phot.mag;em.IR.H double nullable class Browse Object Classification src.class short nullable norm_median_error Uncertainty in the Normalized Median Energy stat.error;stat.param;phys.energy double nullable vmag_extinction The V Band Extinction mag phys.absorption;em.opt.V double nullable irac_5p8_um_mag Spitzer/IRAC 5.8-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable irac_8p0_um_mag_error Error in 8.0-micron Band Magnitude mag stat.error;phot.mag;em.IR.4-8um double nullable nh_error Error in Model Hydrogen Column Density (cm^-2) H-atoms/cm^2 stat.error;phys.columnDensity double nullable q_25_error Error in the Bottom Quartile Value stat.error;stat.param;phys.energy double nullable hmag_error Error in H Magnitude mag stat.error;phot.mag;em.IR.H double nullable location Location within RCW 108 Field meta.id.parent char nullable lii Galactic Longitude degree pos.galactic.lon double nullable kmag The K_S_ Band Magnitude mag phot.mag;em.IR.K double nullable irac_5p8_um_mag_error Error in 5.8-micron Band Magnitude mag stat.error;phot.mag;em.IR.4-8um double nullable reduced_chi_squared Reduced Chi^2 Value stat.fit.chi2 double nullable irac_3p6_um_mag Spitzer/IRAC 3.6-micron Band Magnitude mag phot.mag;em.IR.3-4um double nullable q_75 Top Quartile Value stat.param;phys.energy double nullable off_axis Off-Axis Angle (arcmin) arcmin instr.offset double nullable compressed_median Log of the m/(1-m) Value meta.code;phys.energy double nullable irac_4p5_um_mag_error Error in 4.5-micron Band Magnitude mag stat.error;phot.mag;em.IR.4-8um double nullable q_75_error Error in the Top Quartile Value stat.error;stat.param;phys.energy double nullable energy_quartile_ratio Energy Quartile Ratio Defined as Three Times Q_25 Divided by Q_75 stat.param;phys.energy double nullable irac_4p5_um_mag Spitzer/IRAC 4.5-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable jmag_error Error in J Magnitude mag stat.error;phot.mag;em.IR.J double nullable kmag_error Error in K_S_ Magnitude mag stat.error;phot.mag;em.IR.K double nullable rs_kt_limit Limit Flag for Model Temperature meta.code;phys.temperature;stat.fit char nullable nh Model Hydrogen Column Density (cm^-2) H-atoms/cm^2 phys.columnDensity double nullable nir_excess Infrared Excess, Reddening Free Quantity mag phot.color.excess double nullable irac_3p6_um_mag_error Error in 3.6-micron Band Magnitude mag stat.error;phot.mag;em.IR.3-4um double nullable rs_kt_error Error in Model Temperature (keV) keV stat.error;phys.temperature;stat.fit double nullable norm_median Normalized Median Energy m for the Source, or Q_50 stat.param;phys.energy double nullable q_25 Bottom Quartile Value stat.param;phys.energy double nullable stellar_model Stellar Model Used meta.code;spect;meta.modelled char nullable ir_class Classification of Infrared Source src.class char nullable cxo_irac_offset Offset Between IRAC Detection and X-Ray Centroid Position (arcsec) arcsec double nullable source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable irac_8p0_um_mag Spitzer/IRAC 8.0-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable num_bayesian_blocks Number of Bayesian Blocks > 95% Confidence Required to Describe Lightcurve stat.param short nullable log_lx Log of X-Ray Luminosity (in Units of erg/s) log(erg/s) phys.luminosity;em.X-ray double nullable alt_name Alternative Source Designation Based on Catalog Source Number meta.id char nullable cxo_nir_offset Offset Between Near-Infrared Detection and X-Ray Centroid Position (arcsec) arcsec pos.angDistance;em.X-ray;em.IR double nullable rs_kt Model Temperature (keV) keV phys.temperature;stat.fit double nullable raw_counts Raw Counts ct phot;em.X-ray double nullable absorbed_flux Absorbed Flux (erg/s/cm^2) erg/s/cm^2 phot.flux;em.X-ray double nullable nir_double_flag Flag [a] Indicates VLT Adaptive Optics Data Indicate this Source Is a Double meta.code char 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