J/A+A/594/A82 XMM sources in IC 1805 (Rauw+, 2016)
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 2016A&A...594A..82R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; X-ray sources
Keywords: stars: early-type -
open clusters and associations: individual: IC1805 - X-rays: stars
Abstract:
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 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.
We 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 allow us to revisit the orbital solutions of
BD+60 497 and HD 15558, and provide 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 our XMM-Newton pointing. The very fast rotator
BD+60 513, and to a lesser extent the O4 If+ star HD 15570 appear
somewhat underluminous. Whilst 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.
Description:
The table provides the full catalogue of X-ray sources detected with
the EPIC instruments onboard XMM-Newton inside the IC1805 cluster. The
sources are ordered by increasing right ascension. The coordinates of
the sources were cross-correlated with the optical and IR catalogues
of Straizys et al. (2013, Cat. J/A+A/554/A3), Wolff et al. (2011, Cat.
J/ApJ/726/19), and the SIMBAD catalogue. We adopted in each case a
correlation radius of 4 arcsec.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 167 191 List of X-ray sources detected with XMM-Newton
in IC 1805
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See also:
IX/46 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR5 (XMM-SSC, 2016)
J/ApJ/726/19 : Intermediate-mass stars in IC 1805 (Wolff+, 2011)
J/A+A/554/A3 : Vilnius photometry of IC 1805 stars (Straizys+, 2013)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Designation of the source according to the
IAU convention for XMM-Newton sources
(JHHMMSS.s+DDMMSS)
18- 19 I2 h RAh Right ascension (J2000.0)
21- 22 I2 min RAm Right ascension (J2000.0)
24- 29 F6.3 s RAs Right ascension (J2000.0)
31 A1 --- DE- Declination sing (J2000.0)
32- 33 I2 deg DEd Declination (J2000.0)
35- 36 I2 arcmin DEm Declination (J2000.0)
38- 42 F5.2 arcsec DEs Declination (J2000.0)
44- 46 I3 --- XID Source number ordered by decreasing flux
47 A1 --- u_XID Uncertainty flag on XDI (1)
49- 53 F5.2 10-3ct/s CRMOS1 ? EPIC-MOS1 count rate
55- 58 F4.2 10-3ct/s e_CRMOS1 ? rms uncertainty on CRMOS1
60- 64 F5.2 --- HRMOS1 ? EPIC-MOS1 hardness ratio (2)
66- 70 F5.2 --- e_HRMOS1 ? rms uncertainty on HRMOS1
72- 76 F5.2 10-3ct/s CRMOS2 ? EPIC-MOS2 count rate
78- 81 F4.2 10-3ct/s e_CRMOS2 ? rms uncertainty on CRMOS2
83- 87 F5.2 --- HRMOS2 ? EPIC-MOS2 hardness ratio (2)
89- 92 F4.2 --- e_HRMOS2 ? rms uncertainty on HRMOS2
94- 99 F6.2 10-3ct/s CRPN ? EPIC-pn count rate
101-104 F4.2 10-3ct/s e_CRPN ? rms uncertainty on CRPN
106-110 F5.2 --- HRPN ? EPIC-pn hardness ratio (2)
112-115 F4.2 --- e_HRPN ? rms uncertainty on HRPN
117-143 A27 --- OName Optical counterpart (3)
147-162 A16 --- SpType spectral type of optical counterpart (4)
164-167 A4 --- Note Notes to bibliographic reference for
spectral types (5)
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Note (1): a colon indicates a source that is doubtful because it falls
(partially) in a detector gap or because it falls onto the wings of a
bright source.
Note (2): Hardness ratio 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.
Note (3): IC1805, [MJD95], [SBJLK13] numbers refer to the catalogues of
Vasilevskis et al. (1965AJ.....70..806V 1965AJ.....70..806V, ), Massey et al. (1995, Cat.
J/ApJ/454/151) and Straizys et al. (2013, Cat. J/A+A/554/A3), respectively.
Note (4): Small letters for the spectral type indicate photometric spectral
classifications given by Straizys et al. (2013, Cat. J/A+A/554/A3).
Note (5): Notes as follows:
1 = Straizys et al. (2013, Cat. J/A+A/554/A3)
2 = this work
3 = Shi & Hu (1999A&AS..136..313S 1999A&AS..136..313S)
4 = Antipin (2008PZP.....8...19A 2008PZP.....8...19A)
5 = Wolff et al. (2011, Cat. J/ApJ/726/19)
6 = Sota et al. (2011ApJS..193...24S 2011ApJS..193...24S, Cat. III/274)
7 = Ishida (1970PASJ...22..277I 1970PASJ...22..277I)
* = WISE sources that were classified as YSO candidates by Straizys et al.
(2013, Cat. J/A+A/554/A3)
** = Algol-type eclipsing binary V 1166 Cas (= IC1805 111 = LS I +61 275)
which has an orbital period of 1.3210days (Antipin, 2008PZP.....8...19A 2008PZP.....8...19A)
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Acknowledgements:
Gregor Rauw, rauw(at)astro.ulg.ac.be
(End) Patricia Vannier [CDS] 09-Aug-2016