ORIYSOIR ivo://nasa.heasarc/oriysoir NASA/GSFC HEASARC Prisinzano et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The origin and evolution of the X-ray emission in very young stellar objects (YSOs) are not yet well understood because it is very hard to observe YSOs in the protostellar phase. Using COUP data, the authors studied in their reference paper the X-ray properties of stars in the Orion Nebula Cluster (ONC) in different evolutionary classes: luminosities, hydrogen column densities N<sub>H</sub>, effective plasma temperatures, and time variability were compared to understand if the interaction between the circumstellar material and the central object can influence the X-ray emission. They have assembled the deepest and most complete photometric catalog of objects in the ONC region from the UV to 8 microns (µm) using data from the HST Treasury Program; deep and almost simultaneous UBVI and JHK images taken, respectively, with WFI at ESO 2.2m and ISPI at CTIO 4m telescopes; and Spitzer IRAC imaging. They selected high-probability candidate Class 0-I protostars, a sample of "bona fide" Class II stars, and a set of Class III stars with IR emission consistent with normal photospheres. Their principal result is that Class 0-Ia objects are significantly less luminous in X-rays, in both the total and hard bands, than the more evolved Class II stars with mass larger than 0.5M_{sun}_; the latter show X-ray luminosities similar to those of Class 0-Ib stars. This table contains the JHK and IRAC data, as well as the protostar classifications, for 398 ONC YSOs. This online catalog was created by the HEASARC in October 2010 based on the machine-readable versions of Tables 2, 3, 4 and 5 from the reference paper which were obtained from the CDS (their catalog J/ApJ/677/401). This is a service provided by NASA HEASARC . 2008ApJ...677..401P https://heasarc.gsfc.nasa.gov/W3Browse/all/oriysoir.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=oriysoir& GET text/xml 180 99999 true 83.8065041 -5.5854726 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=oriysoir GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_oriysoir&Action=More+Options&Action=Parameter+Search&ConeAdd=1 STAR CATALOG 0.0166666666666667 Infrared public oriysoir Orion Nebula YSO IR Properties source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable coup_number The COUP Identification Number meta.id.assoc short nullable name Catalog 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 jmag The J Band Magnitude mag phot.mag;em.IR.J double nullable hmag The H Band Magnitude mag phot.mag;em.IR.H double nullable kmag The K Band Magnitude mag phot.mag;em.IR.K double nullable irac_3p6_um_mag Spitzer/IRAC 3.6-micron Band Magnitude mag phot.mag;em.IR.3-4um double nullable irac_4p5_um_mag Spitzer/IRAC 4.5-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable kmag_error Uncertainty in Kmag mag stat.error;phot.mag;em.IR.K double nullable irac_8p0_um_mag Spitzer/IRAC 8.0-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable irac_8p0_um_mag_error Uncertainty in 8.0-micron Band Magnitude mag stat.error;phot.mag;em.IR.4-8um double nullable jmag_error Uncertainty in Jmag mag stat.error;phot.mag;em.IR.J double nullable irac_5p8_um_mag Spitzer/IRAC 5.8-micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable bii Galactic Latitude degree pos.galactic.lat double nullable irac_3p6_um_mag_error Uncertainty in 3.6-micron Band Magnitude mag stat.error;phot.mag;em.IR.3-4um double nullable class Browse Object Classification src.class short nullable source_sample Field Indicates Published Table/Sample from Which the Entry Originates meta.ref;meta.table char nullable lii Galactic Longitude degree pos.galactic.lon double nullable hmag_error Uncertainty in Hmag mag stat.error;phot.mag;em.IR.H double nullable irac_4p5_um_mag_error Uncertainty in 4.5-micron Band Magnitude mag stat.error;phot.mag;em.IR.4-8um double nullable irac_5p8_um_mag_error Uncertainty in 5.8-micron Band Magnitude mag stat.error;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