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ROSETTECXO - Rosette Molecular Cloud Chandra X-Ray Point Source Catalog

HEASARC
Archive

Overview

The authors of this study have explored the young stellar populations in the Rosette Molecular Cloud (RMC) region with high spatial resolution X-ray images from the Chandra X-ray Observatory, which are effective in locating weak-lined T Tauri stars as well as disk-bearing young stars. A total of 395 X-ray point sources are detected, 299 of which (76%) have an optical or near-infrared (NIR) counterpart identified from deep FLAMINGOS images. From X-ray and mass sensitivity limits, the authors infer a total population of ~1700 young stars in the survey region. Based on smoothed stellar surface density maps, they investigate the spatial distribution of the X-ray sources and define three distinctive structures and substructures within them. Structures B and C are associated with previously known embedded IR clusters, while structure A is a new X-ray-identified unobscured cluster. A high-mass protostar RMCX 89 = IRAS 06306+0437 and its associated sparse cluster are studied. The different subregions are not coeval but do not show a simple spatial-age pattern. Disk fractions vary between subregions and are generally <~ 20% of the total stellar population inferred from the X-ray survey. The data are consistent with speculations that triggered star formation around the H II region is present in the RMC, but do not support a simple sequential triggering process through the cloud interior. While a significant fraction of young stars are located in a distributed population throughout the RMC region, it is not clear if they originated in clustered environments.

This HEASARC table contains the 348 primary sources listed in Table 1 of the reference paper, as well as the 47 tentative sources listed in Table 2 (the latter having a likelihood > 10-3 of being a spurious background fluctuation based on Poisson statistics), to make a total of 395 X-ray sources. The information on optical and infrared counterparts to these X-ray sources which was provided in Table 4 of the reference paper has also been included herein. In order to allow users to clearly identify these 2 samples, the HEASARC has created a parameter source_sample which is set to 'P' for the Table 1 primary sources and to 'T' for the Table 2 tentative sources. This HEASARC table also contains the X-ray spectroscopic information derived for 158 sources which have phometric significance (the snr parameter) >= 2.0 which was presented in Table 3 of the reference paper. All spectral fits used the "wabs(apec)" model in XSPEC and assumed 0.3 * Z_Sun abundances. The quoted emission measures and X-ray luminosities assume a distance to the Rosette molecular cloud of 1.4 kpc.


Catalog Bibcode

2009ApJ...696...47W

References

A Chandra Study of the Rosette Star-Forming Complex. II. Clusters in the
Rosette Molecular Cloud
     Wang J., Feigelson E.D., Townsley, L.K., Roman-Zuniga C.G., Lada E.,
     Garmire, G.
    <Astrophys. J., 696, 47-65 (2009)>
    =2009ApJ...696...47W

Provenance

This table was created by the HEASARC in July 2009 based on the merger of electronic versions of tables 1, 2, 3 and 4 from the above reference which were obtained from the ApJ web site.

Parameters

Source_Number
A running X-ray source number in order of increasing J2000.0 Right Ascension.

Alt_Name
An alternative name for the catalogued X-ray source based on the 'RMCX' prefix (for Rosette Molecular Cloud X-ray source) and the X-ray source number, which is used by the authors in the reference paper.

Source_Flag
This flag parameter is set to 'C' to indicate those X-ray sources which are above the photon flux completeness limit for all RMCX detections, i.e., they are in the complete sample of X-ray detections after sensitivity correction (see Section 4.3 of the reference paper for more details).

Name
The IAU-style X-ray source designation using the standard 'CXOU' prefix for Chandra sources, and the J2000.0 coordinates, e.g., 'CXOU JHHMMSS.ss+DDMMSS.s'. Notice that these designations are given to higher precision than the current standard CDS-recommended naming convention for such sources, viz., e.g., 'CXOU JHHMMSS.s+DDMMSS'.

RA
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 decimal degree coordinates to a precision of 10^-6 degrees in the original table.

Dec
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 decimal degree coordinates to a precision of 10^-6 degrees in the original table.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Error_Radius
The estimated 1-sigma random position error, in arcseconds. This was computed as the standard deviation of the local PSF inside the extraction region divided by the square root of the extracted counts.

Off_Axis
The off-axis angle of the X-ray source from the nominal pointing direction, in arcminutes.

Counts
The estimated net counts from the extraction area for the X-ray source, in the total energy band (0.5 - 8.0 keV).

Counts_Error
The average of the Poisson upper and lower 1-sigma error in the X-ray source net counts (including the background contribition).

Bck_Counts
The estimated background counts from the extraction area for the X-ray source in the total energy band (0.5 - 8.0 keV).

HB_Counts
The estimated net counts from the extraction area for the X-ray source in the hard energy band (2.0 - 8.0 keV).

PSF_Fraction
The fraction of the point-spread function (PSF) at the fiducial energy of 1.497 keV that is enclosed within the extraction area for the X-ray source. Note that a reduced PSF fraction (significantly below 90%) may indicate that the source is in a crowded region or on the edge of the field.

SNR
The X-ray source photometric significance computed as the ratio of the net counts to the upper error in the net counts.

Log_Bck_Prob_Limit
This flag parameter is set to '<' if the quoted background probability is an upper limit.

Log_Bck_Prob
The logarithm of the probability that the extracted total-band (0.5 - 8 keV) counts are solely from the background based on Poisson statistics. Some sources in the primary source sample (from Table 1 of the reference paper) have background probabilities above the 0.1% threshold that defines the primary sample because the local background estimates can rise during the final extraction iteration.

Source_Anomaly_Flag
This parameter contains a value of 'g' indicating the presence of the following source anomaly: the fractional time when the source was on a detector (FRACEXPO from mkarf) was <0.9

Source_Variable_Flag
This parameter contains flags which characterise the presence or absence of X-ray source variability based on K-S statistics in the total band, as follows:

    a = no evidence for variability (0.05 < P_KS)
    b = possibly variable (0.005 < P_KS < 0.05)
    c = definitely variable (P_KS < 0.005)
      = no test was performed for sources with <4 total full-band counts,
        or for sources in chip gaps or on field edges
  

Exposure
The effective exposure time of the X-ray source, in seconds. This is the approximate time that the source would have to be observed on-axis to obtain the reported number of counts.

Median_Energy
The background-corrected median photon energy for the photons from the X-ray source in the total band, in keV.

Log_NH_Neg_Err
The lower 90%-confidence interval error in the logarithm of the best fit column density, in H atoms cm-2. More significant digits are used for uncertainties < 0.1 in order to avoid large rounding errors; for consistency, the same number of significant digits is used for both lower and upper uncertainties. Uncertainties are missing when XSPEC was unable to compute them or when their values were so large that the parameter is effectively unconstrained. Fits lacking uncertainties should be considered to merely be a spline to the data made in order to obtain rough estimates of luminosities, and the actual parameter values in such cases are unreliable.

Log_NH
The logarithm of the estimated hydrogen column density to the X-ray source, in H atoms cm-2, derived from spectral fitting.

Log_NH_Flag
This flag parameter is set to 'i' to indicate that the corresponding value of log_nh was frozen at that value in the spectral fitting.

Log_NH_Pos_Err
The upper 90%-confidence interval error in the logarithm of the best fit column density, in H atoms cm-2. More significant digits are used for uncertainties < 0.1 in order to avoid large rounding errors; for consistency, the same number of significant digits is used for both lower and upper uncertainties. Uncertainties are missing when XSPEC was unable to compute them or when their values were so large that the parameter is effectively unconstrained. Fits lacking uncertainties should be considered to merely be a spline to the data made in order to obtain rough estimates of luminosities, and the actual parameter values in such cases are unreliable.

Apec_kT_Neg_Err
The lower 90%-confidence interval error in the APEC plasma temperature of the X-ray source, in keV. More significant digits are used for uncertainties < 0.1 in order to avoid large rounding errors; for consistency, the same number of significant digits is used for both lower and upper uncertainties. Uncertainties are missing when XSPEC was unable to compute them or when their values were so large that the parameter is effectively unconstrained. Fits lacking uncertainties should be considered to merely be a spline to the data made in order to obtain rough estimates of luminosities, and the actual parameter values in such cases are unreliable.

Apec_kT
The APEC plasma temperature of the X-ray source, in keV, derived from spectral fitting.

Apec_kT_Flag
This flag parameter is set to 'i' to indicate that the corresponding value of apec_kt was frozen at that value in the spectral fitting.

Apec_kT_Pos_Err
The upper 90%-confidence interval error in the APEC plasma temperature of the X-ray source, in keV. More significant digits are used for uncertainties < 0.1 in order to avoid large rounding errors; for consistency, the same number of significant digits is used for both lower and upper uncertainties. Uncertainties are missing when XSPEC was unable to compute them or when their values were so large that the parameter is effectively unconstrained. Fits lacking uncertainties should be considered to merely be a spline to the data made in order to obtain rough estimates of luminosities, and the actual parameter values in such cases are unreliable.

Log_EM_Neg_Err
The lower 90%-confidence interval error in the logarithm of the emission measure of the X-ray source, in cm-3. More significant digits are used for uncertainties < 0.1 in order to avoid large rounding errors; for consistency, the same number of significant digits is used for both lower and upper uncertainties. Uncertainties are missing when XSPEC was unable to compute them or when their values were so large that the parameter is effectively unconstrained. Fits lacking uncertainties should be considered to merely be a spline to the data made in order to obtain rough estimates of luminosities, and the actual parameter values in such cases are unreliable.

Log_EM
The logarithm of the emission measure (EM) of the model spectrum fit to the X-ray source, in cm-3.

Log_EM_Pos_Err
The upper 90%-confidence interval error in the logarithm of the emission measure of the X-ray source, in cm-3. More significant digits are used for uncertainties < 0.1 in order to avoid large rounding errors; for consistency, the same number of significant digits is used for both lower and upper uncertainties. Uncertainties are missing when XSPEC was unable to compute them or when their values were so large that the parameter is effectively unconstrained. Fits lacking uncertainties should be considered to merely be a spline to the data made in order to obtain rough estimates of luminosities, and the actual parameter values in such cases are unreliable.

Log_SB_Lx_Obs
The logarithm of the observed soft-band (0.5 - 2 keV) luminosity of the X-ray source, in erg s-1, assuming a distance of 1.4 kpc.

Log_HB_Lx_Obs
The logarithm of the observed hard-band (2 - 8 keV) luminosity of the X-ray source, in erg s-1, assuming a distance of 1.4 kpc.

Log_HB_Lx
The logarithm of the absorption-corrected hard-band (2 - 8 keV) luminosity of the X-ray source, in erg s-1, assuming a distance of 1.4 kpc.

Log_Lx_Obs
The logarithm of the observed total-band (0.5 - 8 keV) luminosity of the X-ray source, in erg s-1, assuming a distance of 1.4

Log_Lx
The logarithm of the absorption-corrected total-band (0.5 - 8 keV) luminosity of the X-ray source, in erg s-1, assuming a distance of 1.4 kpc. This is not given when log_nh > 22.5 cm-2 since the soft-band emission for such cases is essentially unmeasurable.

Source_Notes
This parameter contains additional notes concerning the X-ray source, either '2T' meaning that a two-temperature model was used in the spectral fit, and/or a well-known optical or infrared counterpart name. Some other counterpart identifications and properties for specific sources which were given in the footnotes to Table 4 in the reference paper are as follows:

    RMCX 24  = [MJD95] 289
    RMCX 25  = [MJD95] 278=[TASS4] 712279; V=12.6
    RMCX 27  = [MJD95] 265
    RMCX 32  = [MJD95] 237
    RMCX 42  = [MJD95] 230
    RMCX 48  = [MJD95] 259
    RMCX 54  = [MJD95] 256
    RMCX 57  = [MJD95] 260
    RMCX 65  = HD 259533=[TASS4] 663214; V=10.6, spectral type G0
    RMCX 72  = [BC02] 135
    RMCX 95  = [TASS4] 712310=[VGK85] NGC 2244 +04 199; V=13.2; spectral type A0V
    RMCX 119 = [BC02] 136
    RMCX 164 = HD 46485=[BC02] 138=[TASS4] 663303; spectral type O8
    RMCX 185 = [TASS4] 663323
    RMCX 207 = [BGD93] IRS 4
    RMCX 209 = [BGD93] IRS 2
    RMCX 210 = [BGD93] IRS 5
    RMCX 342 = [TASS4] 663391=[VGK85] NGC 2244 +04 226; spectral type B9V
    RMCX 381 = [TASS4] 1472087=[VGK85] NGC 2244 +04 229; spectral type A0
  
where [MJD95] = Massey, Johnson, & Degioia-Eastwood (1995, ApJ, 454, 151), [BC02] = Berghofer & Christian (2002, A&A, 384, 890), [TASS4] = TASS Mark IV Photometric Survey of the Northern Sky (Droege et al. 2006, PASP, 118, 1666), [VGK85] = Voroshilov et al. (1985, Catalogue of BV Magnitudes and Spectral Classes of 6000 stars), and [BGD93] = Block, Geballe, & Dyson (1993, A&A, 273 L41).

USNO_Name
The USNO B1.0 designation of the optical counterpart to the X-ray source.

Bmag
The B-band magnitude of the optical counterpart to the X-ray source.

Rmag
The R-band magnitude of the optical counterpart to the X-ray source.

Imag
The I-band magnitude of the optical counterpart to the X-ray source.

TwoMASS_Name
The 2MASS source identification of the infrared counterpart to the X-ray source.

Flamingos_ID
The FLAMINGOS Ssurce identification of the infrared counterpart to the X-ray source.

Jmag
The 2MASS and/or FLAMINGOS J-band magnitude of the infrared counterpart to the X-ray source.

Hmag
The 2MASS and/or FLAMINGOS H-band magnitude of the infrared counterpart to the X-ray source

Kmag
The 2MASS and/or FLAMINGOS K_s-band magnitude of the infrared counterpart to the X-ray source

TwoMASS_Flags
This parameter contains the 2MASS quality flags for photometry (ph_qual_flag: the first 3 characters) and for contamination and confusion (cc_flg: characters 4 - 6).

The 2MASS photometric quality flags, ph_qual_ flag, provided in the 2MASS All-Sky Data Release, where characters 1 to 3 refer to the J, H, K_s bands, respectively, have the following meaning:

         A = very high significance detection (>10 SNR)
         B = high significance detection (>7 SNR)
         C = moderate significance detection (>5 SNR)
         D = low significance detection
         E = point-spread fitting poor
         F = reliable photometric errors not available
         U = upper limit on magnitude (source not detected)
         X = source is detected but no valid brightness estimate is available
  
The 2MASS contamination and confusion flags, cc_flg, provided in the 2MASS All-Sky Data Release, where characters 4 to 6 refer to the J, H, K_s bands, respectively, have the following meaning:
         0 = source unaffected by artifacts
         b = band-merge confusion (possible multiple source)
         c = photometric confusion from nearby star
         d = diffraction spike confusion from nearby star
         p = persistence contamination from nearby star
         s = electronic stripe from nearby star
  

IRAC_3p6um_Ctrprt_Flag
This parameter contains a flag which is set to 'c' if the X-ray source has a Spitzer/IRAC 3.6-micron counterpart, else it is set to 'x'.

Source_Sample
This HEASARC-created parameter is set to 'P' for sources from the Table 1 list of primary X-ray sources and to 'T' for those from the Table 2 list of tentative sources (the latter have a likelihood > 10^-3 of being spurious background fluctuations based on Poisson statistics).


Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 3-Aug-2009