SFINCSPCM - Star Formation in Nearby Clouds (SFiNCs) Probable Cluster Members Catalog

Overview

The Star Formation in Nearby Clouds (SFiNCs) project is aimed at providing a detailed study of the young stellar populations and of star cluster formation in the nearby 22 star-forming regions (SFRs) for comparison with the authors' earlier MYStIX survey of richer, more distant clusters. As a foundation for the SFiNCs science studies, in the reference paper homogeneous data analyses of the Chandra X-ray and Spitzer mid-infrared (MIR) archival SFiNCs data are described, and the resulting catalogs of over 15,300 X-ray and over 1,630,000 mid-infrared point sources are presented. On the basis of their X-ray/infrared properties and spatial distributions, nearly 8500 point sources have been identified as probable young stellar members of the SFiNCs regions. Compared to the existing X-ray/mid-infrared publications, the SFiNCs member list increases the census of YSO members by 6%-200% for individual SFRs and by 40% for the merged sample of all 22 SFiNCs SFRs.

Sixty-five X-ray observations of the 22 SFiNCs SFRs made with the imaging array on the Advanced CCD Imaging Spectrometer (ACIS) were extracted from the Chandra archive (spanning from 2000 January to 2015 April). See Tables 1 and 2 of the reference paper for the list of SFRs and the log of Chandra ACIS observations, respectively. The final Chandra-ACIS catalog for the 22 SFiNCs SFRs comprises 15,364 X-ray sources (presented in Tables 3 and 4 and section 3.2 of the reference paper, and available as the HEASARC table, SFINCSXRAY).

To obtain MIR photometry for X-ray objects and to identify and measure MIR photometry for additional non-Chandra disky stars that were missed in previous studies of the SFiNCs regions (typically faint YSOs), the authors have reduced the archived Spitzer-IRAC data by homogeneously applying the MYStIX-based Spitzer-IRAC data reduction methods of Kuhn et al. (2013, ApJS, 209, 29) to the 423 Astronomical Object Request (AORs) data sets for the 22 SFiNCs SFRs (listed in Table 5 of the reference paper). As in MYStIX, the SFiNCs IRAC source catalog retains all point sources with the photometric signal-to-noise ratio > 5 in both [3.6] and [4.5] um channels. This catalog covers the 22 SFiNCs SFRs and their vicinities on the sky and comprises 1,638,654 IRAC sources with available photometric measurements for 100%, 100%, 29%, and 23% of these sources in the 3.6, 4.5, 5.8, and 8.0um bands, respectively (see table 6 and section 3.4 of the reference paper).

Source position cross-correlations between the SFiNCs Chandra X-ray source catalog and an IR catalog, either the "cut-out" IRAC or 2MASS, were made using the steps described in section 3.5 of the reference paper.

Using the ensemble of X-ray and infrared data that they have obtained, the authors selected probable YSOs in the 22 SFRs using selection criteria described in section 4.1 of the reference paper. Tables 7 and 8 of the reference paper provide the list of 8,492 SFiNCs probable cluster members (SPCMs: but see below for a caveat on this number) and their main IR and X-ray properties (see section 4 of the reference paper). This present HEASARC table comprises the contents of these two tables. A fuller list of the X-ray properties of the X-ray-detected SPCMs is available in the HEASARC's SFINCSXRAY table (q.v.).

Catalog Bibcode

2017ApJS..229...28G

References

Star Formation in Nearby Clouds (SFiNCs): X-ray and infrared source catalogs
and membership.
    Getman K.V., Broos P.S., Kuhn M.A., Feigelson E.D., Richert A.J.W., Ota Y.,
    Bate M.R., Garmire G.P.
   <Astrophys. J. Suppl. Ser., 229, 28-28 (2017)>
   =2017ApJS..229...28G    (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in September 2017 based on the CDS Catalog J/ApJS/229/28 files table7.dat (the IR photometry of the SFiNCs probable cluster members) and table8.dat (the main X-ray and other properties of the SFiNCs probable cluster members).

HEASARC Caveat

While preparing this table for ingest, the HEASARC discovered that there were 57 entries which had duplicate entries in which pairs all parameter values were the same except for the SFR name: in one case, they were described as members of the OMC 2-3 SFR, in the alternate as members of ONC Flank N, two SFRs which lie close together in the sky and are at the same distance. The HEASARC is unsure as to whether this is an intentional or unintentional duplication, but be that as it may, the actual number of SFiNCs probable cluster members is thus 8,435 rather than 8,492.

Parameters

SFR_Name
The SFiNCs star formation region (SFR) identifier in which the probable cluster member is associated. The SFRs studied herein and their basic properties are listed in Table 1 of the reference paper.

Name
The designation of the SFiNCs probable cluster member (SPCM) using 1 J2000.0 position-based designation (SPCM JHHMMSS.ss+DDMMSS.s). The prefix adopted herein was not specified in the reference paper but is based on the prefix that these authors adopted for MYStIX probable cluster members, viz., 'MPCM', that is used in the HEASARC's MYSTIXMPCM table.

RA
The Right Ascension of the SPCM 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 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 2MASS near-infrared (NIR) position, or a Spitzer IRAC MIR position.

Dec
The Declination of the SPCM 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 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 2MASS NIR position, or a Spitzer IRAC MIR position.

LII
The Galactic Longitude of the SPCM.

BII
The Galactic Latitude of the SPCM.

TwoMASS_Name
The 2MASS source designation of the SPCM, viz., '2MASS JHHMMSSss+DDMMSSs'.

Jmag
The 2MASS J-band magnitude of the SPCM.

Jmag_Error
The 1-sigma uncertainty in the 2MASS J-band magnitude of the SPCM.

Hmag
The 2MASS H-band magnitude of the SPCM.

Hmag_Error
The 1-sigma uncertainty in the 2MASS H-band magnitude of the SPCM.

Ks_Mag
The 2MASS K_s-band magnitude of the SPCM. y#

Ks_Mag_Error
The 1-sigma uncertainty in the 2MASS K_s-band magnitude of the SPCM.

TwoMASS_Flags
The 2MASS photometry quality and confusion/contamination flags for the SPCM detection. The first 3 bytes are the JHK photometry quality codes: see http://www.ipac.caltech.edu/2mass/releases/allsky/doc/sec1_6b.html#phqual for details. The next 3 bytes are the JHK confusion/contamination codes: see http://www.ipac.caltech.edu/2mass/releases/allsky/doc/sec4_7.html for details.

IRAC_Name
The Spitzer Space Telescope IRAC source designation of the SPCM, viz., 'SSTU GLLL.llll+BB.bbbb'.

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

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

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

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

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

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

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

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

Internal_ACIS_Label
The internal Chandra ACIS source label used within the SFiNCs project for the X-ray source identified as an SPCM.

Xfov_Flag
A flag indicating whether the source is located inside (if set to 1) or outside (if set to 0) the Chandra-ACIS-I field of view.

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

Median_Energy
The median energy of the observed (background-subtracted) counts in the X-ray source, in the 0.5-8 keV band, in keV.

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, as obtained from AE.

Log_NH
The XPHOT-derived logarithm of the absorbing Hydrogen gas column density N_H towards the SPCM, in H atoms cm^-2.

Log_Lx
The logarithm of the intrinsic (absorption-corrected) total-band (0.5-8 keV) X-ray luminosity of the SPCM, in erg s^-1, obtained using the X-ray spectral model XPHOT, and assuming it is at the distance of its parent SFR as given in Table 1 of the reference paper.

IRAC_Alpha
The apparent spectral energy distribution (SED) slope, alpha, as measured in the IRAC range from 3.6 to 8.0 um.

IRAC_Alpha_Error
The 1-sigma uncertainty in the apparent spectral energy distribution (SED) slope, alpha, as measured in the IRAC range from 3.6 to 8.0 um.

YSO_Class
The YSO classification of the SPCM using the following schema:

      NOD = diskless (2532 occurrences);
      DSK = disky (5628 occurrences);
      PMB = possible member without a disk class (303 occurrences);
      FRG = source could be a foreground star or a YSO member of the region
            (29 occurrences).

Abs_Vmag
The V-band extinction of the SPCM calculated using the methods of Getman et al. (2014, ApJ, 787, 108).

Stellar_Age
The stellar age, in Myr, calculated using the methods of Getman et al. (2014, ApJ, 787, 108).

OB_Star_Note
A note for known OB-type stars which can contain related information on the OB star's name, spectral type, and its primary catalog of origin..

Xray_IR_Match_Note
A note which can indicate that the X-ray to IR source match was rejected by the tool match_xy but was reinstated as a legitimate match upon the authors' visual inspection. Such cases are often associated with source binarity and multiplicity. Related comments are provided.

Contact Person

Questions regarding the SFINCSPCM database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:34:50 EDT