CYGOB2XMM - Cygnus OB2 Association XMM-Newton X-Ray Point Source Catalog

Overview

Cyg OB2 is one of the most massive associations of O-type stars in our Galaxy. Despite the large interstellar reddening towards Cyg OB2, many studies, spanning a wide range of wavelengths, have been conducted to more clearly understand this association. X-ray observations provide a powerful tool to overcome the effect of interstellar absorption and study the most energetic processes associated with the stars in Cyg OB2. The author analyses XMM-Newton data to investigate the X-ray and UV properties of massive O-type stars as well as low-mass pre-main sequence stars in Cyg OB2.

Six XMM-Newton observations of the core of Cyg OB2 were obtained. In the analysis, the author paid particular attention to the variability of the X-ray bright OB stars, especially the luminous blue variable candidate Cyg OB2 #12. He found that X-ray variability is quite common among the stars in Cyg OB2. While short-term variations are restricted mostly to low-mass pre-main sequence stars, one third of the OB stars display long-term variations. The X-ray flux of CygO B2 #12 varies by 37%, over timescales from days to years, while its mean log L_X/L_bol amounts to -6.10. These properties suggest that Cyg OB2 wind. Two other X-ray bright O-type stars (MT91 516 and CPR2002A11) display variations that suggest they are interacting wind binary systems.

This table lists the general properties of the X-ray sources detected in Cyg OB2 with the EPIC cameras onboard XMM-Newton as given in Table 2 of the reference paper. An additional list of the properties of the sources detected inside Cyg OB2 with the two UV filters of the OM instrument onboard XMM-Newton which was contained in Table 4 of the reference paper is not included herein.

Catalog Bibcode

2011A&A...536A..31R

References

A multi-epoch XMM-Newton campaign on the core of the massive Cyg OB2
association.
    Rauw G.
    <Astron. Astrophys. 536, A31 (2011)>
    =2011A&A...536A..31R        (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in December 2011 based on CDS Catalog J/A+A/536/A31 file table2.dat.

Parameters

Source_Number
A unique source identification number for every X-ray source in order of increasing J2000.0 Right Ascension.

Alt_Name
A designation for the source using the style recommended by the Dictionary of Nomenclature of Celestial Objects using the '[R2011]' prefix and the X-ray source number.

Name
The name for the X-ray source using the convention recommended by the Dictionary of Nomenclature of Celestial Objects for XMM-Newton sources, viz. the 'XMMU' prefix and the (rounded, not truncated) J2000.0 coordinates (JHHMMSS.s-DDMMSS).

RA
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 seconds of time in the original table.

Dec
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

PN_SB_Rate
The mean EPIC-pn count rate of the X-ray source in the soft band (0.5 - 1.0 keV), in ct s^-1.

PN_SB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

PN_SB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

PN_MB_Rate
The mean EPIC-pn count rate of the X-ray source in the medium band (1.0 - 2.0 keV), in ct s^-1.

PN_MB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

PN_MB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

PN_HB_Rate
The mean EPIC-pn count rate of the X-ray source in the hard band (2.0 - 8.0 keV), in ct s^-1.

PN_HB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

PN_HB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

M1_SB_Rate
The mean EPIC-MOS1 count rate of the X-ray source in the soft band (0.5 - 1.0 keV), in ct s^-1.

M1_SB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

M1_SB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

M1_MB_Rate
The mean EPIC-MOS1 count rate of the X-ray source in the medium band (1.0 - 2.0 keV), in ct s^-1.

M1_MB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

M1_MB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

M1_HB_Rate
The mean EPIC-MOS1 count rate of the X-ray source in the hard band (2.0 keV - 8.0), in ct s^-1.

M1_HB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

M1_HB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

M2_SB_Rate
The mean EPIC-MOS2 count rate of the X-ray source in the soft band (0.5 - 1.0 keV), in ct s^-1.

M2_SB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

M2_SB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

M2_MB_Rate
The mean EPIC-MOS2 count rate of the X-ray source in the medium band (1.0 - 2.0 keV), in ct s^-1.

M2_MB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

M2_MB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

M2_HB_Rate
The mean EPIC-MOS2 count rate of the X-ray source in the hard band (2.0 - 8.0 keV), in ct s^-1.

M2_HB_Prob_Constant
The probability that the X-ray source was constant in the detection in the specified band and instrument.

M2_HB_Num_Obs
The number of observations of the X-ray source in the specified band and instrument.

UVM2mag_AB
The mean UVM2 AB-magnitude of the OM counterpart of the X-ray source.

UVW1mag_AB
The mean UVW1 AB-magnitude of the OM Counterpart of the X-ray source.

OM_Source_Number
The identification mumber of the OM counterpart of the X-ray source.

Jmag
The J magnitude of the 2MASS counterpart of the X-ray source.

Hmag
The H magnitude of the 2MASS counterpart of the X-ray source.

Ks_Mag
The K_s magnitude of the 2MASS counterpart of the X-ray source.

TwoMASS_Flag
The 2MASS quality flag, e.g., "AAA', 'AAU', etc., or 'ncp', '2cp', '3cp', where '2cp' ('3cp') means there are 2 (3) 2MASS counterparts inside the 4 arcsecs correlation radius, and 'ncp' means that no 2MASS counterpart was found inside the correlation radius.

Vmag
The V magnitude of the optical counterpart of the X-ray source from Massey & Thompson (1991, AJ, 101, 1408).

UB_Color
The U-B color of the optical counterpart of the X-ray source from Massey & Thompson (1991, AJ, 101, 1408).

BV_Color
The B-V color of the optical Counterpart of the X-ray source from Massey & Thompson (1991, AJ, 101, 1408).

Comments
Comments on the spectral type and/or an alternative commonly used designation for the source.

Contact Person

Questions regarding the CYGOB2XMM database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Wednesday, 23-Nov-2022 19:34:11 EST