CEPBOB3OID ivo://nasa.heasarc/cepbob3oid NASA/GSFC HEASARC Getman et al. 2026-10-02 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The Cepheus B (Cep B) molecular cloud and a portion of the nearby Cep OB3b OB association, one of the most active regions of star formation within 1 kpc, have been observed with the Infrared Array Camera (IRAC) detector on board the Spitzer Space Telescope. The goals were to study protoplanetary disk evolution and processes of sequential triggered star formation in the region. Out of ~400 pre-main-sequence (PMS) stars selected with an earlier Chandra X-ray Observatory observation, ~95% are identified with mid-infrared sources and most of these are classified as diskless or disk-bearing stars. The discovery of the additional >200 IR-excess low-mass members gives a combined Chandra+Spitzer PMS sample that is almost complete down to 0.5 * M<sub>sun</sub> outside of the cloud, and somewhat above 1 * M<sub>sun</sub> in the cloud. The X-ray observations of the Cep B/Cep OB3b region and their data analysis are described in detail by Getman et al. (2006, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/163/306">CDS Cat. J/ApJS/163/306</a>, HEASARC CEPBOB3CXO table). The 30 ks exposure was obtained on 2003 March 11.51-11.88 with the Advanced CCD Imaging Spectrometer (ACIS) detector on board the Chandra X-ray Observatory as part of the ACIS Instrument Team's Guaranteed Time Observations (ObsId No. 3502, P.I.: G. Garmire). The mid-IR observation of Cep B and Cep OB3b was obtained on 2007 February 18 with the IRAC detector on the Spitzer Space Telescope in the 3.6, 4.5, 5.8, and 8.0 micron channels. This was a General Observer project (program identification No. 30361; P.I.: J. Wang). This table contains the optical and infrared counterpart information on the 431 X-ray sources detected by Chandra. It does not contain the 224 IR-excess objects which were not detected as X-ray sources (listed in Table 3 of the reference paper) that are thought to be additional low-mass members of this complex. This table was created by the HEASARC in August 2011 primarily based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/699/1454">CDS catalog J/ApJ/699/1454</a> files table.dat and table 2.dat which list the optical and infrared counterpart information on the 431 X-ray sources detected by Chandra. The names and positions of these X-ray sources were taken from the Getman et al. (2006, ApJS, 163, 306) Catalog, which is available as the HEASARC Browse table CEPBOB3CXO. This is a service provided by NASA HEASARC . 2009ApJ...699.1454G https://heasarc.gsfc.nasa.gov/W3Browse/all/cepbob3oid.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=cepbob3oid& GET text/xml 180 99999 true 344.009031 62.510958 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=cepbob3oid GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_cepbob3oid&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 Infrared Optical public cepbob3oid Cep B/OB3 Star-Forming Region Chandra Point Source Optical/IR ID source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable name IAU Source Designation (CXOCEPB+) 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 cxo_2mass_offset 2MASS-X-Ray Positional Offset (arcsec) arcsec pos.angDistance;em.X-ray;em.IR double nullable jmag 2MASS Johnson J-Band Magnitude mag phot.mag;em.IR.J double nullable cxo_irac_offset IRAC-X-Ray Positional Offset (arcsec) arcsec pos.angDistance;em.X-ray;em.IR double nullable irac_3p6_um_mag Spitzer/IRAC Magnitude in 3.6-Micron Band mag phot.mag;em.IR.3-4um double nullable irac_sed_slope Observed SED Slope in IRAC Bands arith.grad;src double nullable irac_qual_flag IRAC Aperture Photometry and Confusion/Contamination Flag meta.code;em.IR char nullable subregion_name Source Position Projection Region meta.id.parent char nullable bii Galactic Latitude degree pos.galactic.lat double nullable vmag Johnson V-Band Magnitude mag phot.mag;em.opt.V double nullable irac_3p6_um_mag_error Error in Spitzer/IRAC Magnitude in 3.6-Micron Band mag stat.error;phot.mag;em.IR.3-4um double nullable hmag 2MASS Johnson H-Band Magnitude mag phot.mag;em.IR.H double nullable irac_8p0_um_mag Spitzer/IRAC Magnitude in 8.0-Micron Band mag phot.mag;em.IR.4-8um double nullable td_flag Flag Indicates Possible Transition Disk Candidates meta.code;src.class char nullable irac_8p0_um_mag_error Error in Spitzer/IRAC Magnitude in 8.0-Micron Band mag stat.error;phot.mag;em.IR.4-8um double nullable irac_pos_flag Flag Indicates Source Position in/out of IRAC FOVs meta.code;obs char nullable irac_sed_slope_error Error in Observed SED Slope in IRAC Bands stat.error;arith;src double nullable jmag_extinction J-Band Source Extinction mag phys.absorption;em.IR.J double nullable broad_type Membership and YSO Classification src.class char nullable alt_name Alternative Catalog Source Designation meta.id char nullable num_bands_sed_slope Number of IRAC Bands Used for Slope Determination meta.number;obs short nullable lii Galactic Longitude degree pos.galactic.lon double nullable twomass_flags 2MASS Photometry Quality and Confusion/Contamination Flags meta.code;src char nullable irac_4p5_um_mag Spitzer/IRAC Magnitude in 4.5-Micron Band mag phot.mag;em.IR.4-8um double nullable vi_color_error Error in V-Ic Color Index mag stat.error;phot.color;em.opt.V;em.opt.I double nullable irac_5p8_um_mag_error Error in Spitzer/IRAC Magnitude in 5.8-Band mag stat.error;phot.mag;em.IR.4-8um double nullable vmag_error Error in Johnson V-Band Magnitude mag stat.error;phot.mag;em.opt.V double nullable irac_4p5_um_mag_error Error in Spitzer/IRAC Magnitude in 4.5-Micron Band mag stat.error;phot.mag;em.IR.4-8um double nullable hmag_error Error in 2MASS Johnson H-Band Magnitude mag stat.error;phot.mag;em.IR.H double nullable stellar_mass Stellar Mass (Solar Masses) Solar_Mass phys.mass double nullable vi_color V-Ic Color Index mag phot.color;em.opt.V;em.opt.I double nullable ks_mag 2MASS Johnson Ks-Band Magnitude mag phot.mag;em.IR.K double nullable cxo_opt_offset Optical-X-Ray Positional Offset (arcsec) arcsec pos.angDistance;em.X-ray;em.opt double nullable ccd_flag Flag Indicates Source Position on IR Color-Color Diagrams meta.code;src.class char nullable ks_mag_error Error in 2MASS Johnson Ks-Band Magnitude mag stat.error;phot.mag;em.IR.K double nullable jmag_error Error in 2MASS Johnson J-Band Magnitude mag stat.error;phot.mag;em.IR.J double nullable irac_5p8_um_mag Spitzer/IRAC Magnitude in 5.8-Band mag phot.mag;em.IR.4-8um 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