SWIRE/Chandra Lockman Hole Field X-Ray Source Catalog

SWIRE/Chandra Lockman Hole Field X-Ray Source Catalog SWIRELHCXO ivo://nasa.heasarc/swirelhcxo NASA/GSFC HEASARC Wilkes et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The authors have carried out a moderate-depth (70 ks), contiguous 0.7 square degrees Chandra survey in the Lockman Hole Field of the Spitzer/SWIRE Legacy Survey coincident with a completed, ultra-deep VLA survey with deep optical and near-infrared imaging in-hand. The primary motivation is to distinguish starburst galaxies and active galactic nuclei (AGNs), including the significant, highly obscured (log NH > 23 cm-2) subset. Chandra has detected 775 X-ray sources to a limiting broadband (0.3 - 8 keV) flux of ~4 x 10-16 erg cm-2 s-1. This table contains the X-ray catalog, fluxes, hardness ratios, and multi-wavelength fluxes. The log N versus log S agrees with those of previous surveys covering similar flux ranges. The Chandra and Spitzer flux limits are well matched: 771 (99%) of the X-ray sources have infrared (IR) or optical counterparts, and 333 have MIPS 24-micron detections. There are four optical-only X-ray sources and four with no visible optical/IR counterpart. The very deep (~2.7 microJansky rms) VLA data yield 251 (> 4 sigma) radio counterparts, 44% of the X-ray sources in the field. The authors confirm that the tendency for lower X-ray flux sources to be harder is primarily due to absorption. As expected, there is no correlation between observed IR and X-ray fluxes. Optically bright, type 1, and red AGNs lie in distinct regions of the IR versus X-ray flux plots, demonstrating the wide range of spectral energy distributions in this sample and providing the potential for classification/source selection. Many optically bright sources, which lie outside the AGN region in the optical versus X-ray plots (fr/fx > 10), lie inside the region predicted for red AGNs in IR versus X-ray plots, consistent with the presence of an active nucleus. More than 40% of the X-ray sources in the VLA field are radio-loud using the classical definition of RL. The majority of these are red and relatively faint in the optical so that the use of RL to select those AGNs with the strongest radio emission becomes questionable. Using the 24-micron to radio flux ratio (q24) instead results in 13 of the 147 AGNs with sufficient data being classified as radio-loud, in good agreement with the ~10% expected for broad-lined AGNs based on optical surveys. The authors conclude that q24 is a more reliable indicator of radio-loudness. Use of RL should be confined to the optically selected type 1 AGN. This table was created by the HEASARC in December 2009 based on the machine-readable versions of Tables 3, 4 and 7 from the reference paper which was obtained from the Astrophysical Journal web site. This is a service provided by NASA HEASARC . 2009ApJS..185..433W https://heasarc.gsfc.nasa.gov/W3Browse/all/swirelhcxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=swirelhcxo& GET text/xml 180 99999 true 161.052125 58.53877778 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=swirelhcxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_swirelhcxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 SPITZER 0.0166666666666667 Infrared Optical X-ray public swirelhcxo SWIRE/Chandra Lockman Hole Field 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 count_rate Net 0.3-8.0 keV Count Rate ct/s phot.count;em.X-ray double nullable count_rate_error Error on Net 0.3-8.0 keV Count Rate ct/s stat.error;phot.count;em.X-ray double nullable fb_flux Broad 0.3-8.0 keV Flux erg/s/cm^2 phot.flux;em.X-ray double nullable rmag_limit Limit Flag for the r-Prime Band Magnitude meta.code;phot.mag;em.opt.R char nullable rmag The r-Prime Band Magnitude mag phot.mag;em.opt.R double nullable rmag_error Error in the r-Prime Band Magnitude mag stat.error;phot.mag;em.opt.R double nullable flux_3p6_um The 3.6-micron Flux Density (mJy) mJy phot.flux.density;em.IR.3-4um double nullable flux_3p6_um_error Error in the 3.6-micron Flux Density (mJy) mJy stat.error;phot.flux.density;em.IR.3-4um double nullable counts Net 0.3-8.0 keV Counts ct phot;em.X-ray double nullable bii Galactic Latitude degree pos.galactic.lat double nullable gmag_error Error in the g-Prime Band Magnitude mag stat.error;phot.mag;em.opt.B double nullable flux_20_cm_error Error in the 20-cm Flux Density (mJy) mJy stat.error;phot.flux.density;em.radio.750-1500MHz double nullable flux_24_um The 24-micron Flux Density (mJy) mJy phot.flux.density;em.IR.15-30um double nullable flux_8_um_limit Limit Flag for the 8.0-micron Flux Density meta.code;phot.flux.density;em.IR.4-8um char nullable hardness_ratio_neg_err Lower Error for Hardness Ratio stat.error;phot.flux;arith.ratio;em.X-ray double nullable error_radius Positional Uncertainty (arcsec) arcsec stat.error;pos double nullable hb_flux Hard 2.5-8.0 keV Flux erg/s/cm^2 phot.flux;em.X-ray.medium double nullable flux_20_cm_limit Limit Flag for the 20-cm Flux Density meta.code;phot.flux.density;em.radio.750-1500MHz char nullable flux_24_um_limit Limit Flag for the 24-micron Flux Density meta.code;phot.flux.density;em.IR.15-30um char nullable lii Galactic Longitude degree pos.galactic.lon double nullable notes Source-Specific Notes meta.note char nullable hardness_ratio Hardness Ratio phot.flux;arith.ratio;em.X-ray double nullable flux_8_um The 8.0-micron Flux Density (mJy) mJy phot.flux.density;em.IR.4-8um double nullable sb_flux Soft 0.3-2.5 keV Flux erg/s/cm^2 phot.flux;em.X-ray.soft double nullable hardness_ratio_pos_err Upper Error for Hardness Ratio stat.error;phot.flux;arith.ratio;em.X-ray double nullable gmag The g-Prime Band Magnitude mag phot.mag;em.opt.B double nullable flux_8_um_error Error in the 8.0-micron Flux Density (mJy) mJy stat.error;phot.flux.density;em.IR.4-8um double nullable counts_error Error on Net 0.3-8.0 keV Counts ct stat.error;phot;em.X-ray double nullable flux_20_cm The 20-cm Flux Density (mJy) mJy phot.flux.density;em.radio.750-1500MHz double nullable flux_24_um_error Error in the 24-micron Flux Density (mJy) mJy stat.error;phot.flux.density;em.IR.15-30um double nullable swire_id SWIRE Identification meta.id.cross char nullable flux_density_1_kev The 1-keV Flux Density (erg/s/cm^2/Hz) erg/s/cm^2/Hz phot.flux.density;em.X-ray.soft double nullable gmag_limit Limit Flag for the g-Prime Band Magnitude meta.code;phot.mag;em.opt.B 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 off_set Distance between X-Ray and SWIRE Sources (arcsec) arcsec pos.angDistance;em.X-ray;em.IR double nullable