IC1805XMM - IC 1805 XMM-Newton X-Ray Source Catalog

Overview

Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC 1805 open cluster is very interesting as it hosts the O4 If+ star HD 15570 that is thought to be in an evolutionary stage intermediate between a normal O-star and a Wolf-Rayet star. Such a star could provide a test for theoretical models aiming at explaining the empirical scaling relation between the X-ray and bolometric luminosities of O-type stars.

The authors have observed IC 1805 with XMM-Newton and further collected optical spectroscopy of some of the O-star members of the cluster. The optical spectra allowed them to revisit the orbital solutions of BD +60 497 and HD 15558, and provided the first evidence of binarity for BD +60 498. X-ray emission from colliding winds does not appear to play an important role among the O-stars of IC 1805. Notably, the X-ray fluxes do not vary significantly between archival X-ray observations and the present XMM-Newton pointing. The very fast rotator BD +60 513, and to a lesser extent the O4 If+ star HD 15570, appear somewhat underluminous. While the underluminosity of HD 15570 is only marginally significant, its amplitude is found to be compatible with theoretical expectations based on its stellar and wind properties. A number of other X-ray sources are detected in the field, and the brightest objects, many of which are likely low-mass pre-main sequence stars, are analyzed in detail.

This table provides the full catalog of the 191 X-ray sources detected with the EPIC detectors onboard XMM-Newton in the direction of the IC 1805 cluster. The coordinates of the sources were cross-correlated with the optical and IR catalogs of Straizys et al. (2013, A&A, 554, A3), Wolff et al. (2011, ApJ, 726, 19), and the SIMBAD database. The authors adopted in each case a correlation radius of 4 arcseconds.

Catalog Bibcode

2016A&A...594A..82R

References

X-ray and optical spectroscopy of the massive young open cluster IC 1805.
    Rauw G., Naze Y.
    <Astron. Astrophys. 594, A82 (2016)>
    =2016A&A...594A..82R        (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in October 2016 based on the electronic version of Table A1 from the reference paper which was obtained from the CDS (their catalog J/A+A/594/A82 file tablea1.dat).

Parameters

Source_Number
A unique identification number for each X-ray source in the catalog in order of decreasing flux.

Name
The conventional XMM-Newton source name using the standard 'XMMU' prefix, e.g., 'XMMU 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 0.001 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 0.01 arcseconds in the original table.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Source_Flag
This flag parameter is set to ':' to indicate that a source is doubtful because it falls (partially) in a detector gap or because it falls onto the wings of another bright source.

M1_Count_Rate
The EPIC-MOS1 count rate of the X-ray source in the 0.4-10 keV band, in counts per second (converted by the HEASARC from the ct/ks used in the original table).

M1_Count_Rate_Error
The rms uncertainty in the EPIC-MOS1 count rate of the X-ray source in the 0.4-10 keV band, in counts per second (converted by the HEASARC from the ct/ks used in the original table).

M1_Hardness_Ratio
The EPIC-MOS1 hardness ratio HR of the X-ray source, where HR is defined as (H-S)/(H+S), where S and H refer to the count rates in the soft (0.4-2.0keV) and hard (2.0-10.0keV) energy bands, respectively.

M1_Hardness_Ratio_Error
The rms uncertainty in the EPIC-MOS1 hardness ratio HR of the X-ray source.

M2_Count_Rate
The EPIC-MOS2 count rate of the X-ray source in the 0.4-10 keV band, in counts per second (converted by the HEASARC from the ct/ks used in the original table).

M2_Count_Rate_Error
The rms uncertainty in the EPIC-MOS2 count rate of the X-ray source in the 0.4-10 keV band, in counts per second (converted by the HEASARC from the ct/ks used in the original table).

M2_Hardness_Ratio
The EPIC-MOS2 hardness ratio HR of the X-ray source, where HR is defined as (H-S)/(H+S), where S and H refer to the count rates in the soft (0.4-2.0keV) and hard (2.0-10.0keV) energy bands, respectively.

M2_Hardness_Ratio_Error
The rms uncertainty in the EPIC-MOS2 hardness ratio HR of the X-ray source.

PN_Count_Rate
The EPIC-PN count rate of the X-ray source in the 0.4-10 keV band, in counts per second (converted by the HEASARC from the ct/ks used in the original table).

PN_Count_Rate_Error
The rms uncertainty in the EPIC-PN count rate of the X-ray source in the 0.4-10 keV band, in counts per second (converted by the HEASARC from the ct/ks used in the original table).

PN_Hardness_Ratio
The EPIC-PN hardness ratio HR of the X-ray source, where HR is defined as (H-S)/(H+S), where S and H refer to the count rates in the soft (0.4-2.0keV) and hard (2.0-10.0keV) energy bands, respectively.

PN_Hardness_Ratio_Error
The rms uncertainty in the EPIC-PN hardness ratio HR of the X-ray source.

Optical_Name
The name of the optical (or, in a few cases, infrared) counterpart found within 4 arcseconds of the X-ray source position. The prefixes IC1805, [MJD95], and [SBJLK13] refer to the catalogs of Vasilevskis et al. (1965, AJ, 70, 806), Massey et al. (1995, ApJ, 454, 151) and Straizys et al. (2013, A&A, 554, A3), respectively.

Spect_Type
The spectral type of the optical counterpart to the X-ray source.

Spect_Type_Flag
This flag parameter is set to the value of 'P' to indicate that the quoted spectral type is a photometric spectral classifications given by Straizys et al. (2013, A&A, 554, A3) rather than a 'classic' spectral type .

Ref_Spect_Type
A bibliographic reference code for the source of the spectral type, as follows:

     1 = Straizys et al. (2013, A&A, 554, A3)
     2 = this work
     3 = Shi & Hu (1999, A&AS, 136, 313)
     4 = Antipin (2008, PZP, 8, 19)
     5 = Wolff et al. (2011, ApJ, 726, 19)
     6 = Sota et al. (2011, ApJS, 193, 24)
     7 = Ishida (1970, PASJ, 22, 277)
     8 = WISE sources that were classified as YSO candidates by Straizys et al.
         (2013, A&A, 554, A3)
     9 = Algol-type eclipsing binary V 1166 Cas (= IC1805 111 = LS I +61 275)
         which has an orbital period of 1.3210 days (Antipin, 2008, PZP, 8, 19)

Class
The HEASARC Browse object classification based on the value of the spectral type parameter (spect_type), if one is available.

Contact Person

Questions regarding the IC1805XMM database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: Wednesday, 29-Jan-2020 16:34:40 EST