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MYSTIXMPCM - Massive Young Star-Forming Complex Study in IR & X-Rays: MYStIX Probable Complex Members

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Overview

The Massive Young Star-forming complex Study in Infrared and X-rays (MYStIX) project requires samples of young stars that are likely members of 20 nearby Galactic massive star-forming regions. Membership is inferred from statistical classification of X-ray sources, from detection of a robust infrared excess that is best explained by circumstellar dust in a disk or infalling envelope and from published spectral types that are unlikely to be found among field stars. This table contains the MYStIX membership lists, which total 31,549 probable complex members. In their reference paper, the authors describe in detail the statistical classification of X-ray sources via a "Naive Bayes Classifier". These membership lists provide the empirical foundation for subsequent MYStIX science studies.

The MYStIX project, described by Feigelson et al. (2013, ApJS, 209, 26), seeks to identify and study samples of young stars in 20 nearby (0.4 < D < 3.6kpc) Galactic massive star-forming regions (MSFRs). These samples are derived using X-ray data from the Chandra X-ray Observatory, near-infrared (NIR) photometry from the United Kingdom InfraRed Telescope (UKIRT) and from the Two Micron All Sky Survey (2MASS), mid-infrared (MIR) photometry from the Spitzer Space Telescope, and from published spectroscopically-identified massive stars. The purpose of this study is to describe the authors' efforts to minimize contaminants in the MYStIX catalogs of young stars. They refer to these latter objects as the "MYStIX Probable Complex Members" or MPCMs. This table contains the combined MPCM catalog for all 20 of the MYStIX MSFRs. This MPCM catalog is the union of three sets of probable members identified by three different established methods for identifying young stars (see Feigelson et al. 2013, ApJS, 209, 26, Fig. 3).

Most of the X-ray information on the MPCMs (with the exception of the X-ray luminosities and absorbing column densities obtained using XPHOT) was produced by the ACIS Extract (AE) software package (Broos et al. 2010, ApJ, 714, 1582 and 2012, Astrophysics Source Code Library, 1203.001). The AE software and User's Guide are available at http://www.astro.psu.edu/xray/acis/acis_analysis.html. X-ray quantities using the 'fb' prefix are for the full or total energy band from 0.5 - 8.0 keV, those using the 'sb' prefix are for the soft band from 0.5 - 2.0 keV, and those using the 'hb' prefix are for the hard band from 2.0 - 8.0 keV. L. K. Townsley and P. S. Broos (2013, in preparation) and Kuhn et al. (2013, ApJS, 209, 27) identify a few very bright X-ray sources in each region that suffer from a type of instrumental non-linearity known as photon pile-up (http://cxc.harvard.edu/ciao/why/pileup_intro.html); X-ray properties reported for those sources are biased and should be used with caution.


Catalog Bibcode

2013ApJS..209...32B

References

Identifying young stars in massive star-forming regions for the MYStIX project.
    Broos P.S., Getman K.V., Povich M.S., Feigelson E.D., Townsley L.K.,
    Naylor T., Kuhn M.A., King R.R., Busk H.A.
   <Astrophys. J. Suppl. Ser., 209, 32 (2013)>
   =2013ApJS..209...32B

Provenance

This table was created by the HEASARC in February 2014 based on CDS Catalog J/ApJS/209/32 file mpcm.dat.

Parameters

SFR_Name
The designation of the MYStIX star-forming region. See Table 2 of Feigelson et al. (2013, ApJS, 209, 26) for more information on the SFRs in this study.

Name
The IAU-style J2000 position-based source designation, e.g., 'MPCM JHHMMSS.ss+DDMMSS.s', where 'MPCM' stands for 'MYStIX Probable Complex Member', as recommended by the authors. The MYStIX source name is the sexagesimal representation of the MYStIX source position. In rare cases two MPCM entries will share the same source position, because two X-ray sources have been assigned the same NIR counterpart by the authors' counterpart identification algorithm. In such cases they append an 'a' or 'b' to the source names to make them unique.

RA
The Right Ascension of the MPCM in the selected equinox. This was given in J2000 decimal degree coordinates to an accuracy of 10-6 degrees (0.0036 arcseconds) in the original reference. The MYStIX source position reported here is the most accurate position among the multi-wavelength detections that the authors judged to be the same object - a Chandra X-ray position, a UKIDSS (UKIRT Infrared Deep Sky Survey) or 2MASS NIR position, or a Spitzer MIR position.

Dec
The Declination of the MPCM in the selected equinox. This was given in J2000 decimal degree coordinates to an accuracy of 10-6 degrees (0.0036 arcseconds) in the original reference. The MYStIX source position reported here is the most accurate position among the multi-wavelength detections that the authors judged to be the same object - a Chandra X-ray position, a UKIDSS (UKIRT Infrared Deep Sky Survey) or 2MASS NIR position, or a Spitzer MIR position.

LII
The Galactic Longitude of the MPCM.

BII
The Galactic Latitude of the MPCM.

Error_Radius
The 1-sigma radius of the error circle around the MPCM position, in arcseconds.

Position_Origin
The origin of the position. This can be, for example, a Chandra X-ray position, a UKIRT or 2MASS NIR position, or a Spitzer MIR position. The full set of possible values is:

    Megeath2012 = Megeath et al., (2012, AJ, 144, 192) from a Spitzer survey of
                  Orion A and B molecular clouds.
    OBcat       = Massive stars (B3 or earlier) were drawn from the literature
                  collections of Skiff (2009, CDS Cat. B/mk) and SIMBAD, and
                  from a list given in section 2 of the reference paper. Note
                  that these spectroscopically identified OB stars typically do
                  not have IR excesses and some, but not all, have X-ray
                  detections.
    Chandra     = X-ray position
    Spitzer     = Mid-IR position from Spitzer
    UKIDSS      = near-IR position from UKIDSS survey (see CDS Cats. II/316,
                  II/319)
    TWOMASS     = near-IR position from 2MASS (CDS Cat. II/246)
  

Xray_Name
The IAU-style J2000 position-based X-ray source designation, e.g., 'CXO JHHMMSS.ss+DDMMSS.s'. Notice that these designations are non-standard according to the guidelines of the Dictionary of Nomenclature of Celestial Objects, which would suggest that they should be of the form 'CXOU JHHMMSS.s+DDMMSS', i.e., with the prefix CXOU for Chandra X-ray Observatory, Unregistered, and lower-precision coordinates.

Internal_Xray_Name
The X-ray source name used within the MYStIX project for the source. These internal source labels identify Chandra pointings; they do not convey membership in astrophysical clusters. L.K. Townsley & P.S. Broos (2013, in preparation) and Kuhn et al. (2013, ApJS, 209, 27) identify a few very bright X-ray sources in each region that suffer from a type of instrumental non-linearity known as photon pile-up (http://cxc.harvard.edu/ciao/why/pileup_intro.html); X-ray properties reported for these sources are biased and should be used with caution.

NIR_Name
The name of the source in the NIR catalog, using the 'NIR' prefix and either an IAU-style J2000 position-based X-ray source designation, e.g., 'NIR JHHMMSS.ss+DDMMSS.s' or a source number, e.g., 'NIR 10'. NIR catalogs were constructed by combining deep UKIRT catalogs (King et al. 2013, ApJS, 209, 28), where available, with bright stars from the 2MASS catalog (Skrutskie et al. 2006, CDS Cat. VII/233).

NIR_Label
The label (internal name) of the source in the NIR Catalog.

MIR_Name
The name of the source in the MIR catalog, using the 'MIR' prefix and either an IAU-style J2000 position-based X-ray source designation, e.g., 'MIR JHHMMSS.ss+DDMMSS.s' or a source number, e.g., 'MIR 1420'. MIR catalogs were obtained from local reductions of Spitzer observations (Kuhn et al. 2013, ApJS, 209, 29), from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE; Benjamin et al. 2003, PASP, 115, 953, see CDS Cat. II/293), and from the Vela-Carina Survey (Spitzer Proposal ID 40791, PI S. Majewski). Feigelson et al. (2013, ApJS, 209, 26, Table 2) report which IR catalogs were available for each MYStIX MSFR.

MIR_Label
The label (internal name) of the source in the MIR Catalog

Ob_Cat_Label
The label (name) of the source in the OB Catalog. When a source has been associated with a known massive star, all parameters derived from the XPHOT spectral model (Getman et al. 2010, ApJ, 708, 1760), viz., the inferred X-ray luminosities and column densities, are considered unreliable.

Xray_Source_Number
The 'zero-based index' number of the source in the X-Ray catalog for the MSFR in which it lies: thus, this is not unique by itself, but the combination of sfr_name and xray_source_number does uniquely identify a MYStIX X-ray source.

Ire_Source_Number
The 'zero-based index' number of the source in the IR-excess catalog (Povich et al. 2013, ApJS, 209, 31, the HEASARC MYSTIXIRES table) for the MSFR in which it lies: thus, this is not unique by itself, but the combination of sfr_name and ire_source_number does uniquely identify a MYStIX IR-excess source.

Spect_Type
The spectral type of the MPCM.

Ref_Spect_Type
The reference from which the spectral type was taken, coded as follows (references with codes 0 -10 are cited in Gagne et al. 2011, ApJS, 194, 5):

  Value               BibCode             Reference

    0                 ??
    2                 1988PASP..100.1431M Morell et al.
    3                 2002MNRAS.336.1099A Albacete et al.
    4                 2001ASPC..242..195F Freyhammer et al.
    7                 2001A&A...368..212R Rauw et al.
    8                 2013yCat....1.2023S Skiff,                 2009-2013, Cat. B/mk
    9                 2011ApJS..193...24S Sota
   10                                     Walborn                2010, private communication
   11                 2010ApJ...711L.143W Walborn et al.
  A07                 2007ApJ...660.1480M Maiz Apellaniz et al.
  B12                 2012ApJ...744...87B Bik et al.
  C80                 1980A&A....91..186C Chini et al.
  C08                 2008RMxAC..34..102C Costero et al.
  E12                 2012ASPC..464..351E Ellerbroek et al.
  G05                 2005ApJS..160..353G Getman et al.          Cat. J/ApJS/160/353
  H12                 2012ApJ...757..113H Hirsch et al.
  H08                 2008ApJ...686..310H Hoffmeister et al.
  L06                 2006MNRAS.371..252L Levenhagen and Leister Cat. J/MNRAS/371/252
  SD06                2006A&A...448..351S Simon-Diaz et al.
  K07                 2007A&A...466..649K Kraus et al.
  NS11                2011A&A...532A...2N Nieva and Simon-Diaz
  RM09                2009A&A...498..961R Renson and Manfroid    Cat. III/260
  S81                 1981A&A....95...94S Schulz et al.
  S11                 2011ApJS..193...24S Sota et al.
  SHUPING             2012AJ....144..116S Shuping et al.
  SKIFF               2013yCat....1.2023S                        Cat. B/mk
  SIMBAD                                                         http://simbad.u-strasbg.fr/simbad/
  

Ob_Cat_Mag
The apparent magnitude of the MPCM, if there is photometry available for it in the OB Catalog.

Ob_Cat_Mag_Band
The photometric band for the quoted magnitude of the MPCM in the OB Catalog, (J, K or V).

Prob_No_Src_Min
The smallest p-value for the no-source hypothesis (Broos et al. 2010, ApJ, 714, 1582, Section 4.3) for the X-ray emission of the MPCM among the 3 X-ray bands (soft, hard and full). (In statistical hypothesis testing, the p-value is the probability of obtaining a test statistic at least as extreme as the one that was actually observed when the null hypothesis is true).

Single_Ks_Prob
The smallest p-value for the one-sample Kolmogorov-Smirnov statistic under the no-variability null hypothesis within a single-observation for the X-ray emission of the MPCM. See Broos et al. (2010, ApJ, 714, 1582, Section 7.6) for a description of the variability metrics.

Merged_Ks_Prob
The smallest p-value for the one-sample Kolmogorov-Smirnov statistic under the no-variability null hypothesis over the merged observations for the X-ray emission of the MPCM. See Broos et al. (2010, ApJ, 714, 1582, Section 7.6) for a description of the variability metrics and for caveats regarding possible spurious indications of variability using this merged observations metric.

Nominal_Exposure
The total exposure time in the merged X-ray observations of the MPCM, in seconds.

Frac_Expo
The fraction of the nominal exposure time in which the source was observed in the merged X-ray observations. Due to dithering over inactive portions of the focal plane, a Chandra source is often not observed during some fraction of the nominal exposure time (See http://cxc.harvard.edu/ciao/why/dither.html). The reported quantity is FRACEXPO produced by the CIAO tool mkarf.

Num_Obs_Extracted
The total number of X-ray observations of the source that were extracted.

Num_Obs_Merged
The number of X-ray observations of the source that were merged so as to estimate its photometric properties.

Off_Axis_Min
The smallest off-axis angle ThetaLo of the source among the merged X-ray observations, in arcminutes.

Off_Axis
The average off-axis angle Theta of the source among the merged X-ray observations, in arcminutes.

Off_Axis_Max
The largest off-axis angle ThetaHi of the source among the merged X-ray observations, in arcminutes.

PSF_Fraction
The average PSF fraction at 1.5 keV for the source in the merged X-ray observations.

Afterglow_Fraction
The suspected afterglow fraction. Since the extracted event data are lightly cleaned to avoid removing legitimate X-ray events from bright sources (Broos et al. 2010, Section 3), some background events arising from an effect known as "afterglow" (http://cxc.harvard.edu/ciao/why/afterglow.html) will remain and may contaminate the source extractions, despite careful procedures to identify and remove them during data preparation . After extraction, the authors attempted to identify afterglow events using the tool ae_afterglow_report (see the AE manual at http://www.astro.psu.edu/xray/acis/acis_analysis.html) and here they report the fraction of the extracted events that were attributed to afterglow.

FB_Total_Counts
The observed total-band (0.5-8 keV) total counts in the X-ray source in the merged apertures.

FB_Counts
The net (background-subtracted) total-band (0.5-8 keV) counts in the X-ray source in the merged apertures.

SB_Counts
The net (background-subtracted) soft-band (0.5-2 keV) counts in the X-ray source in the merged apertures.

HB_Counts
The net (background-subtracted) hard-band (2-8 keV) counts in the X-ray source in the merged apertures.

FB_Counts_Neg_Err
The 1-sigma lower error in the net (background-subtracted) total-band (0.5-8 keV) counts in the X-ray source in the merged apertures. The confidence intervals (68%) for the net counts quantities are estimated by the CIAO tool aprates: see http://asc.harvard.edu/ciao/ahelp/aprates.html

FB_Counts_Pos_Err
The 1-sigma upper error in the net (background-subtracted) total-band (0.5-8 keV) counts in the X-ray source in the merged apertures. The confidence intervals (68%) for the net counts quantities are estimated by the CIAO tool aprates: see http://asc.harvard.edu/ciao/ahelp/aprates.html

SB_Counts_Neg_Err
The 1-sigma lower error in the net (background-subtracted) soft-band (0.5-2 keV) counts in the X-ray source in the merged apertures. The confidence intervals (68%) for the net counts quantities are estimated by the CIAO tool aprates: see http://asc.harvard.edu/ciao/ahelp/aprates.html

SB_Counts_Pos_Err
The 1-sigma upper error in the net (background-subtracted) soft-band (0.5-2 keV) counts in the X-ray source in the merged apertures. The confidence intervals (68%) for the net counts quantities are estimated by the CIAO tool aprates: see http://asc.harvard.edu/ciao/ahelp/aprates.html

HB_Counts_Neg_Err
The 1-sigma lower error in the net (background-subtracted) hard-band (2-8 keV) counts in the X-ray source in the merged apertures. The confidence intervals (68%) for the net counts quantities are estimated by the CIAO tool aprates: see http://asc.harvard.edu/ciao/ahelp/aprates.html

HB_Counts_Pos_Err
The 1-sigma upper error in the net (background-subtracted) hard-band (2-8 keV) counts in the X-ray source in the merged apertures. The confidence intervals (68%) for the net counts quantities are estimated by the CIAO tool aprates: see http://asc.harvard.edu/ciao/ahelp/aprates.html

FB_Median_Energy
The median energy of the observed spectrum of the X-ray source, in the 0.5-8 keV band, in keV. This is the AE quantity ENERG_PCT50_OBSERVED, the median energy of extracted events, corrected for background events (Broos et al. 2010, ApJ, 714, 1582, Section 7.3).

FB_Log_Photon_Flux
The logarithm of the incident photon flux in the total (0.5-8 keV) band, in photon cm-2 s-1. This is the net counts over the product of the mean effective area in this band (the full-band arf value) and the nominal exposure time (see Broos et al. 2010, ApJ, 714, 1582, Section 7.4).

SB_Log_Photon_Flux
The logarithm of the incident photon flux in the soft (0.5-2 keV) band, in photon cm-2 s-1. This is the net counts over the product of the mean effective area in this band (the full-band arf value) and the nominal exposure time (see Broos et al. 2010, ApJ, 714, 1582, Section 7.4)

HB_Log_Photon_Flux
The logarithm of the incident photon flux in the hard (2-8 keV) band, in photon cm-2 s-1. This is the net counts over the product of the mean effective area in this band (the full-band arf value) and the nominal exposure time (see Broos et al. 2010, ApJ, 714, 1582, Section 7.4)

HB_Lx_Obs
The observed hard-band (2-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

HB_Lx
The absorption-corrected hard-band (2-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

HB_Lx_Stat_Err
The 1-sigma statistical uncertainty in the absorption-corrected hard-band (2-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

HB_Lx_Sys_Err
The 1-sigma systematic uncertainty in the absorption-corrected hard-band (2-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

FB_Lx_Obs
The observed total-band (0.5-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

FB_Lx
The absorption-corrected total-band (0.5-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

FB_Lx_Stat_Err
The 1-sigma statistical uncertainty in the absorption-corrected full-band (0.5-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

FB_Lx_Sys_Err
The 1-sigma systematic uncertainty in the absorption-corrected full-band (0.5-8 keV) luminosity of the MPCM, in erg s-1, obtained using the X-ray spectral model XPHOT from Getman et al. (2010, ApJ, 708, 1760).

Log_NH
The logarithm of the absorbing gas column density NH, in H atoms cm-2, obtained using XPHOT.

Log_NH_Stat_Err
The 1-sigma statistical uncertainty in the logarithm of the absorbing gas column density NH, in H atoms cm-2, obtained using XPHOT.

Log_NH_Sys_Err
The 1-sigma systematic uncertainty in the logarithm of the absorbing gas column density NH, in H atoms cm-2, obtained using XPHOT.

Xray_NIR_Prob_Cp
The counterpart probability for associating the X-ray and NIR sources, the XN_PROB_CP quantity, taken from Naylor et al. (2013, ApJS, 209, 30).

Xray_MIR_Prob_Cp
The counterpart probability for associating the X-ray and MIR sources, the XM_PROB_CP quantity, taken from Naylor et al. (2013, ApJS, 209, 30).

Jmag
The J-band magnitude of the MPCM.

Jmag_Error
The 1-sigma uncertainty in the J-band magnitude of the MPCM: the column j_msigcom from the 2MASS catalog or the column ERROR_J from King et al. 2013, ApJS, 209, 28).

Hmag
The H-band magnitude of the MPCM.

Hmag_Error
The 1-sigma uncertainty in the H-band magnitude of the MPCM: the column h_msigcom from the 2MASS catalog or the column ERROR_H from King et al. 2013, ApJS, 209, 28).

Kmag
The K-band magnitude of the MPCM.

Kmag_Error
The 1-sigma uncertainty in the K-band magnitude of the MPCM: the column k_msigcom from the 2MASS catalog or the column ERROR_K from King et al. 2013, ApJS, 209, 28).

IRAC_3p6_um_Mag
The Spitzer/IRAC 3.6-um magnitude of the MPCM.

IRAC_3p6_um_Mag_Error
The 1-sigma uncertainty in the Spitzer/IRAC 3.6-um magnitude of the MPCM.

IRAC_4p5_um_Mag
The Spitzer/IRAC 4.5-um magnitude of the MPCM.

IRAC_4p5_um_Mag_Error
The 1-sigma uncertainty in the Spitzer/IRAC 4.5-um magnitude of the MPCM.

IRAC_5p8_um_Mag
The Spitzer/IRAC 5.8-um magnitude of the MPCM.

IRAC_5p8_um_Mag_Error
The 1-sigma uncertainty in the Spitzer/IRAC 5.8-um magnitude of the MPCM.

IRAC_8p0_um_Mag
The Spitzer/IRAC 8.0-um magnitude of the MPCM.

IRAC_8p0_um_Mag_Error
The 1-sigma uncertainty in the Spitzer/IRAC 8.0-um magnitude of the MPCM.

Jmag_Flag
The UKIRT photometry flag for the J-band magnitude: see King et al. (2013, ApJS, 209, 28).

Hmag_Flag
The UKIRT photometry flag for the H-band magnitude:see King et al. (2013, ApJS, 209, 28).

Kmag_Flag
The UKIRT photometry flag for the K-band magnitude: see King et al. (2013, ApJS, 209, 28).

TwoMASS_Flag
The 2MASS photometry flag, CC_FLG.

TwoMASS_Quality_Flag
The 2MASS photometry quality flag, PH_QUAL.

Glimpse_Jmag_Flag
The GLIMPSE photometry flag for the J-band magnitude.

Glimpse_Hmag_Flag
The GLIMPSE photometry flag for the H-band magnitude.

Glimpse_Kmag_Flag
The GLIMPSE photometry flag for the K-band magnitude.

Glimpse_3p6_um_Flag
The GLIMPSE photometry flag for the Spitzer/IRAC 3.6um band magnitude.

Glimpse_4p5_um_Flag
The GLIMPSE photometry flag for the Spitzer/IRAC 4.5um band magnitude.

Glimpse_5p8_um_Flag
The GLIMPSE photometry flag for the Spitzer/IRAC 5.8um band magnitude.

Glimpse_8p0_um_Flag
The GLIMPSE photometry flag for the Spitzer/IRAC 8.0um band magnitude.

Local_Spitzer_Flag
The local Spitzer photometry flag (Kuhn et al. 2013, ApJS, 209, 29) as follows:

      4 = 4-pixel aperture used;
      3 = 3-pixel aperture used;
      2 = 2-pixel aperture used and contaminating flux is <10% of source flux;
     -1 = 2-pixel aperture used and contaminating flux is >10% of source flux.
  

Ref_Jmag
The origin of the J-band magnitude photometry for the MPCM.

Ref_Hmag
The origin of the H-band magnitude photometry for the MPCM.

Ref_Kmag
The origin of the K-band magnitude photometry for the MPCM.

Ref_IRAC_3p6_um_Mag
The origin of the 3.6um-band magnitude photometry for the MPCM.

Ref_IRAC_4p5_um_Mag
The origin of the 4.5um-band magnitude photometry for the MPCM.

Ref_IRAC_5p8_um_Mag
The origin of the 5.8um-band magnitude photometry for the MPCM.

Ref_IRAC_8p0_um_Mag
The origin of the 8.0um-band magnitude photometry for the MPCM.

SED_Class
The SED classification of the MPCM based on its IR spectrum, from Povich et al. (2013, ApJS, 209, 31):

    0 = Likely YSO,
    1 = Starburst galaxy with strong PAH emission,
    2 = Obscured AGN with intrinsic dust emission,
    3 = Unresolved nebular knot of PAH emission in H II region.
  

Vmag_Extinction
The visual extinction AV of the MPCM, in magnitudes, determined from the chi2-weighted mean of all acceptable SED fits. See Section 4.1 of Povich et al. (2013, ApJS, 209, 31) for more details and some caveats.

YSO_Stage
The evolutionary stage classification of the MPCM derived from fitting its SED with the YSO models of Robitaille et al. (2006, ApJS, 167, 256), as given in Povich et al. (2013, ApJS, 209, 31) and using the following schema:

        1 = Stage 0/I YSO dominated by infalling, dusty envelope,
        2 = Stage II/III YSO dominated by optically thick (II) or thin (III)
            circumstellar disk,
       -1 = ambiguous case.
  

H1_Prior
The H1 class prior probability (position-dependent) for the MPCM. The authors use a "Naive Bayes Classifier". They define a set of mutually exclusive classification hypotheses, denoted as {H1, H2, H3, H4}, that represent the four types of objects that Chandra detects in MYStIX observations: young stars in the MSFR, and three populations of contaminants:

  H1: source is a foreground Galactic field star
  H2: source is a young star in the MSFR
  H3: source is a background Galactic field star
  H4: source is an extragalactic object
  
For each contaminant population (H1, H3, H4), the authors create a map of the expected density of detected X-ray sources across the Chandra field of view, by applying adaptive kernel smoothing to a two-dimensional histogram of the positions of simulated contaminants (Section 3.2 of reference paper). They also create a density map for the observed catalog of X-ray sources, rhoobs(r), via adaptive smoothing. These four density maps are functions of celestial position, and have units of detected X-ray sources per unit area on the sky. The simple arithmetic in Equation (1) of the reference paper transforms those surface density maps into unitless maps representing the fraction of observed X-ray sources expected to belong to each class, based only on source location. For further details, see Section 3.1 of the reference paper.

H2_Prior
The H2 class prior probability (position-dependent) for the MPCM (see the discussion for the h1_prior parameter above for more details).

H3_Prior
The H3 class prior probability (position-dependent) for the MPCM (see the discussion for the h1_prior parameter above for more details).

H4_Prior
The H4 class prior probability (position-dependent) for the MPCM (see the discussion for the h1_prior parameter above for more details).

H1_Posterior
The H1 Class Posterior Probability for the MPCM (see the discussion for the h1_prior parameter above for more details).

H2_Posterior
The H2 Class Posterior Probability for the MPCM (see the discussion for the h1_prior parameter above for more details).

H3_Posterior
The H3 Class Posterior Probability for the MPCM (see the discussion for the h1_prior parameter above for more details).

H4_Posterior
The H4 Class Posterior Probability for the MPCM (see the discussion for the h1_prior parameter above for more details).

H2_Dominant_Factor
The H2 (that the source is a young star in the MSFR) dominant classification term ("H2f"). This reports the classifier term that exerts the most influence on the H2 posterior probability as follows:

      1 = prior,
      2 = MedianEnergy,
      3 = J magnitude,
      4 = X-ray variability,
      5 = spectral type,
      6 = 4.5um magnitude,
      7 = infrared SED model.
  

Xray_Class_Code
The X-ray classification of the MPCM using the following coding schema:

      0 = unclassified
      1 = H1: source is a foreground Galactic field star
      2 = H2: source is a young star in the MSFR (Galactic massive star-forming
           region)
      3 = H3: source is a background Galactic field star
      4 = H4: source is an extragalactic object
  

Class
The HEASARC Browse object classification, based on the spectral type parameter value.


Contact Person

Questions regarding the MYSTIXMPCM database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 24-Feb-2014