NGC2024CXO ivo://nasa.heasarc/ngc2024cxo NASA/GSFC HEASARC Skinner et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The NGC 2024 Chandra X-Ray Point Source Catalog contains the results of a sensitive 76 ks Chandra observation of the young stellar cluster in NGC 2024, lying at a distance of ~415 pc in the Orion B giant molecular cloud. Previous infrared observations have shown that this remarkable cluster contains several hundred embedded young stars, most of which are still surrounded by circumstellar disks. Thus, it presents a rare opportunity to study X-ray activity in a large sample of optically invisible protostars and classical T Tauri stars (CTTSs) undergoing accretion. Chandra detected 283 X-ray sources, of which 248 were identified with counterparts at other wavelengths, mostly in the near-infrared. Astrometric registration of Chandra images against the Two Micron All Sky Survey (2MASS) resulted in positional offsets of ~0.25" near field center, yielding high confidence identifications of infrared counterparts. The Chandra detections are characterized by hard, heavily absorbed spectra and specular variability. Spectral analysis of more than 100 of the brightest X-ray sources yields a mean V-band extinction of ~10.5 magnitudes and typical plasma energies <kT> ~ 3 keV. Chandra detected all but one of a sample of 27 classical T Tauri stars (CTTSs) identified from previous near- and mid-infrared photometry, and their X-ray and bolometric luminosities are correlated. IRS 2b, which is thought to be a massive embedded late O or early B star that may be the ionizing source of NGC 2024, is detected as an X-ray source. Seven millimeter-bright cores (FIR 1-7) in NGC 2024 that may be protostellar were not detected, with the possible exception of faint emission near the unusual core FIR 4. This table was created by the HEASARC in January 2007 based on CDS table J/ApJ/598/375/table1.dat. This is a service provided by NASA HEASARC . 2003ApJ...598..375S https://heasarc.gsfc.nasa.gov/W3Browse/all/ngc2024cxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=ngc2024cxo& GET text/xml 180 99999 true 85.390875 -2.06577778 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=ngc2024cxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_ngc2024cxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public ngc2024cxo NGC 2024 Chandra X-Ray Point Source Catalog name Object Designation (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 (0.5-7keV) Counts ct phot;em.X-ray short nullable counts_error Uncertainty in Net (0.5-7keV) Counts ct stat.error;phot;em.X-ray short nullable flux Absorbed (0.5-7keV) Flux (erg/s/cm^2) erg/s/cm^2 phot.flux;em.X-ray double nullable log_lx Log of the (0.5-7keV) Unabsorbed Luminosity in Units of erg/s log(ergs/s) double nullable ctrpart_name Candidate IR, Optical, or Radio Identification char nullable log_lx_var_flag Flag Indicates Variable Luminosity char nullable bii Galactic Latitude degree pos.galactic.lat double nullable nh_neg_err Lower 90% Confidence Error for Hydrogen Absorption Column Density H-atoms/cm^2 stat.error;phys.columnDensity double nullable source_number Running Object Number meta.id short nullable te_plasma_neg_err Lower 90% Confidence Error for Characteristic Plasma Temperature keV double nullable nh Hydrogen Absorption Column Density H-atoms/cm^2 phys.columnDensity double nullable mean_photon_energy Mean (0.5-7keV) Photon Energy (keV) keV double nullable alt_name Alternate Designation for Object meta.id char nullable notes_flag Flag [Yf] for Source Note char nullable nh_pos_err Upper 90% Confidence Error for Hydrogen Absorption Column Density H-atoms/cm^2 stat.error;phys.columnDensity double nullable te_plasma Characteristic Plasma Temperature keV double nullable lii Galactic Longitude degree pos.galactic.lon double nullable te_plasma_pos_err Upper 90% Confidence Error for Characteristic Plasma Temperature keV double nullable ks_var_statistic Kolmogorov-Smirnov Variability Statistic 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