Massive Star-Forming Regions Omnibus X-Ray Catalog MOXC ivo://nasa.heasarc/moxc NASA/GSFC HEASARC Townsley et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the Massive Star-forming Regions (MSFRs) Omnibus X-ray Catalog (MOXC), a compendium of X-ray point sources from Chandra/ACIS observations of a selection of MSFRs across the Galaxy, plus 30 Doradus in the Large Magellanic Cloud. MOXC consists of 20,623 X-ray point sources from 12 MSFRs with distances ranging from 1.7 kpc to 50 kpc, and comprises Table 3 of the reference paper. In their paper, the authors show the morphology of the unresolved X-ray emission that remains after the cataloged X-ray point sources are excised from the ACIS data, in the context of Spitzer and WISE observations that trace the bubbles, ionization fronts, and photon-dominated regions that characterize MSFRs. In previous work, they have found that this unresolved X-ray emission is dominated by hot plasma from massive star wind shocks. This diffuse X-ray emission is found in every MOXC MSFR, clearly demonstrating that massive star feedback (and the several-million-degree plasmas that it generates) is an integral component of MSFR physics. The Chandra observations used for the Massive Star-forming Regions Omnibus X-ray Catalog (MOXC) are summarized in Table 2 of the reference paper and have dates ranging from 2000-04-03 to 2013-01-31 for the 12 MSFRs: the 7 MYStIX targets NGC 6334, NGC 6357, M 16, M 17, W 3, W 4 and NGC 3576, and the 5 "beyond-MYStIX" targets G333.6-0.2, W 51A, G29.96-0.02, NGC 3603 and 30 Doradus. A similar table to MOXC for other MYStIX targets was presented by Kuhn et al. (2013, ApJS, 209, 27, available as the HEASARC MYSTIXXRAY table). The main difference between that table and the MOXC version is that the present authors have chosen to omit absorption-corrected X-ray source luminosities from the XPHOT algorithm (Getman et al. 2010, ApJ, 708, 1760) herein, because those quantities are given in Broos et al. (2013, ApJS, 209, 32, available as the HEASARC MYSTIXMPCM table) for relevant MYStIX X-ray sources (those classified as pre-main sequence stars). For beyond-MYStIX targets, the authors chose to postpone XPHOT calculations until the X-ray sources were classified, since XPHOT estimates are only appropriate for pre-MS stars. The XPHOT code is available (Getman et al. 2012, Astrophysics Source Code Library, record ascl.soft12002) if others wish to use it on MOXC sources. All photometric quantities in this table are apparent (not corrected for absorption). The HEASARC has used prefixes 'fb_', 'sb_' and 'hb_' (replacing the suffixes '_t', '_s' and '_h' used in the reference paper) on the names of the X-ray photometric quantities which designate the full (total, 0.5 - 8 keV), soft (0.5 - 2.0 keV) and hard (2-8 keV) energy bands. Correction for finite extraction apertures is applied to the ancillary reference file (ARF) calibration products (see Broos et al. 2010, ApJ, 714, 1582, Section 5.3); the total_counts and counts quantities characterize the extraction and are not aperture-corrected. The only calibrated quantities presented are the apparent photon fluxes, in units of photon cm<sup>-2</sup> s<sup>-1</sup> (see Broos et al. 2010, ApJ, 714, 1582, Section 7.4), and estimates for the apparent energy fluxes, in units of erg cm<sup>-2</sup> s<sup>-1</sup> (Getman et al. 2010, ApJ, 708, 1760). This table was created by the HEASARC in October 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/213/1">CDS Catalog J/ApJS/213/1</a> files table3.dat (the MOXC X-ray Source Catalog) and table6.dat (the list of MOXC sources in previously published Chandra catalogs). This is a service provided by NASA HEASARC . 2014ApJS..213....1T https://heasarc.gsfc.nasa.gov/W3Browse/all/moxc.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=moxc& GET text/xml 180 99999 true 84.711184 -69.258517 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=moxc GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_moxc&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public moxc Massive Star-Forming Regions Omnibus X-Ray Catalog sfr_name Massive Star-Forming Region (MSFR) Designation meta.id.assoc char nullable name X-Ray Source Designation (CXOU JHHMMSS.ss+DDMMSS.s) 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 error_radius 1-Sigma Position Error Circle arcsec stat.error;pos double nullable fb_counts Net 0.5-8keV Counts in Merged Apertures ct phot;em.X-ray double nullable fb_counts_neg_err 1-Sigma Lower Bound on Net 0.5-8keV Counts ct stat.error;phot;em.X-ray double nullable fb_counts_pos_err 1-Sigma Upper Bound on Net 0.5-8keV Counts ct stat.error;phot;em.X-ray double nullable fb_median_energy Median 0.5-8keV Energy, Observed Spectrum keV phys.energy double nullable sb_obs_flux Apparent Energy Flux in Soft (0.5-2keV) Band erg/s/cm^2 phot.flux;em.X-ray.soft double nullable afterglow_fraction Suspected Afterglow Fraction meta.code;instr.det double nullable hb_obs_flux Apparent Energy Flux in Hard (2-8keV) Band erg/s/cm^2 phot.flux;em.X-ray.medium double nullable off_axis_max Largest Value of Theta arcmin instr.offset;stat.max double nullable nominal_exposure Total Exposure Time in Merged Observations s time.duration;obs.exposure double nullable hb_counts_pos_err 1-Sigma Upper Bound on Net 2-8keV ct stat.error;phot;em.X-ray.medium double nullable sb_obs_photon_flux Apparent Photon Flux in Soft (0.5-2keV) Band photon/cm^2/s phot.flux;em.X-ray.soft double nullable aperture_area Average Aperture Area for Merged Observations in (0.492arcsec)^2^ pixel meta.code;phys.angArea double nullable hb_median_energy Median 2-8keV Energy, Observed Spectrum keV phys.energy double nullable num_obs_extracted Total Number of Observations Extracted meta.number;obs short nullable fb_obs_photon_flux Apparent Photon Flux in Total (0.5-8keV) Band photon/cm^2/s phot.flux;em.X-ray double nullable sb_arf_value Mean Effective Area (ARF Value) in cm^2^.Count/Photon in 0.5-2keV ct.cm^2/photon phot;instr.det;em.X-ray.soft double nullable pos_algorithm Algorithm Used to Estimate Position meta.code char nullable hb_counts Net 2-8keV Counts in Merged Apertures ct phot;em.X-ray.medium double nullable prev_cat_moxc_offset Offset Between MOXC and Published Positions arcsec pos.angDistance;em.X-ray double nullable bck_scaling Scaling of Background Extraction meta.code;instr.background double nullable merged_ks_prob Smallest p-Value under No-Variability Null Hypothesis over Merged Observations stat.probability double nullable hb_obs_photon_flux Apparent Photon Flux in Hard (2-8keV) Band photon/cm^2/s phot.flux;em.X-ray.medium double nullable sb_median_energy Median 0.5-2keV Energy, Observed Spectrum keV phys.energy double nullable hb_total_counts Observed 2-8keV Counts in Merged Apertures ct phot;em.X-ray.medium int nullable hb_prob_no_src p-Value for 2-8keV No-Source Hypothesis stat.probability double nullable bii Galactic Latitude degree pos.galactic.lat double nullable fb_bck_counts Observed 0.5-8keV Counts in Merged Background Regions ct phot;instr.background;em.X-ray int nullable hb_counts_neg_err 1-Sigma Lower Bound on Net 2-8keV ct stat.error;phot;em.X-ray.medium double nullable fb_total_counts Observed 0.5-8keV Counts in Merged Apertures ct phot;em.X-ray int nullable off_axis_min Smallest Value of Theta arcmin instr.offset;stat.min double nullable fb_arf_value Mean Effective Area (ARF Value) in cm^2^.Count/Photon in 0.5-8keV ct.cm^2/photon phot;instr.det;em.X-ray double nullable sb_counts_pos_err 1-Sigma Upper Bound on Net 0.5-2keV Counts ct stat.error;phot;em.X-ray.soft double nullable sb_bck_counts Observed 0.5-2keV Counts in Merged Background Regions ct phot;instr.background;em.X-ray.soft short nullable hb_arf_value Mean Effective Area (ARF Value) in cm^2^.Count/Photon in 2-8keV ct.cm^2/photon phot;instr.det;em.X-ray.medium double nullable num_obs_merged Number of Observations Merged to Estimate Photometry Properties meta.number;obs short nullable prev_cat_source_number Published Chandra Catalog Sequence Identifier meta.id.cross short nullable frac_expo_discard Fraction of Exposure discarded in Merged Observations meta.code;time.duration;obs.exposure double nullable lii Galactic Longitude degree pos.galactic.lon double nullable frac_expo Fraction of Nominal Exposure During Which Source Was Observed meta.code;time.duration;obs.exposure double nullable sb_counts Net 0.5-2keV Counts in Merged Apertures ct phot;em.X-ray.soft double nullable hb_bck_counts Observed 2-8keV Counts in Merged Background Regions ct phot;instr.background;em.X-ray.medium short nullable rate_in_3x3_cell 0.5-8keV Rate in 3x3 CCD Pixel Cell ct/frame meta.code double nullable psf_fraction Average PSF Fraction at 1.5keV for Merged Observations instr.det.psf double nullable fb_prob_no_src p-Value for 0.5-8keV No-Source Hypothesis stat.probability double nullable internal_name X-Ray Source Designation Used in the Project meta.id char nullable sb_prob_no_src p-Value for 0.5-2keV No-Source Hypothesis stat.probability double nullable off_axis Average Off-Axis Angle Theta for Merged Observations arcmin instr.offset double nullable sb_total_counts Observed 0.5-2keV Counts in Merged Apertures ct phot;em.X-ray.soft int nullable sb_counts_neg_err 1-Sigma Lower Bound on Net 0.5-2keV Counts ct stat.error;phot;em.X-ray.soft double nullable prob_no_src_min Merged p-Value for No-Source Hypothesis (smallest of no-t/no-s/no-h) stat.probability;stat.min double nullable fb_obs_flux Apparent Energy Flux in Total (0.5-8keV) Band erg/s/cm^2 phot.flux;em.X-ray double nullable single_ks_prob Smallest p-Value under No-Variability Null Hypothesis within a Single Obs. stat.probability double nullable prev_cat_name Published Chandra Catalog Identifier meta.id.cross 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