Description
The Massive Young Star-Forming Complex Study in Infrared and X-rays (MYStIX) project provides a comparative study of 20 Galactic massive star-forming complexes with distances between 0.4 and 3.6 kpc. Probable stellar members in each target complex are identified using X-ray and/or infrared data via two pathways: (1) X-ray detections of young/massive stars with coronal activity/strong winds or (2) infrared excess (IRE) selection of young stellar objects (YSOs) with circumstellar disks and/or protostellar envelopes. In this particular study, the authors present the methodology for the second pathway using Spitzer/IRAC, 2MASS, and UKIRT imaging and photometry. Although IRE selection of YSOs is well-trodden territory, MYStIX presents unique challenges. The target complexes range from relatively nearby clouds in uncrowded fields located toward the outer Galaxy (e.g., NGC 2264, the Flame Nebula) to more distant, massive complexes situated along complicated, inner Galaxy sightlines (e.g., NGC 6357, M 17). The authors combine IR spectral energy distribution (SED) fitting with IR color cuts and spatial clustering analysis to identify IRE sources and to isolate probable YSO members in each MYStIX target field from the myriad types of contaminating sources that can resemble YSOs: extragalactic sources, evolved stars, nebular knots, and even unassociated foreground/background YSOs. Applying their methodology consistently across 18 of the target complexes, they produce the MYStIX IRE Source (MIRES) Catalog comprising 20,719 sources, including 8,686 probable stellar members of the MYStIX target complexes. They also classify the SEDs of 9,365 IR counterparts to MYStIX X-ray sources to assist the first pathway, the identification of X-ray-detected stellar members. The MYStIX project, described by Feigelson et al. (2013, ApJS, 209, 26), provides a comprehensive, parallel study of 20 Galactic massive star-forming regions. The basic input data for the MIRES Catalog were near-IR (NIR) and mid-IR (MIR) photometric catalogs. The authors also used NIR and MIR images and mosaics for visualizing the point-source populations with respect to various nebular structures. They provide high-level descriptions of each input catalog in section 2 of the reference paper. This table contains the MYStIX IRE Source (MIRES) Catalog comprising IR data on 20,719 sources, including 8,686 probable stellar members of the MYStIX target complexes, viz., massive star-forming regions (MSFRs), which was given in Table 2 of the reference paper. It does not include the IR data of the above-mentioned 9,365 IR counterparts to MYStIX X-ray sources (the SED Classification of IR Counterparts to MYStIX X-ray sources (SCIM-X Catalog) that were listed in Table 7 of the reference paper. This table was created by the HEASARC in February 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/209/31">CDS Catalog J/ApJS/209/31</a> file table2.dat. This is a service provided by NASA HEASARC .
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