J/MNRAS/392/L55 Globular clusters in M31 from K-band photometry (Peacock+, 2009)
Wide field CAMera survey of M31 globular clusters: low-mass X-ray binaries.
Peacock M.B., Maccarone T.J., Waters C.Z., Kundu A., Zepf S.E., Knigge C.,
Zurek D.R.
<Mon. Not. R. Astron. Soc., 392, L55-L59 (2009)>
=2009MNRAS.392L..55P 2009MNRAS.392L..55P
ADC_Keywords: Galaxies, nearby ; Clusters, globular ; Morphology ; Magnitudes
Keywords: binaries: general - globular clusters: general - X-rays: binaries
Abstract:
We investigate the relationship between low-mass X-ray binaries
(LMXBs) and globular clusters (GCs) using United Kingdom Infrared
Telescope (UKIRT) observations of M31 and existing Chandra,
XMM-Newton and ROSAT catalogues. By fitting King models to these
data, we have estimated the structural parameters and stellar
collision rates of 239 of its GCs. We show a highly significant trend
between the presence of a LMXB and the stellar collision rate of a
cluster. The stellar collision rate is found to be a stronger
predictor of which clusters will host LMXBs than the host cluster
mass. We argue that our results show that the stellar collision rate
of the clusters is the fundamental parameter related to the production
LMXBs. This is consistent with the formation of LMXBs through
dynamical interactions with little direct dependence on the neutron
star retention fraction or cluster mass.
Description:
To investigate the properties of the GCs in M31, we obtained K-band
photometry using the Wide Field CAMera (WFCAM) on the United Kingdom
Infrared Telescope (UKIRT) under the service program USERV1652.
Our observations were taken on the nights of 2005 November 30 and 2007
August 06 with seeing of 0.85-1.00 and 0.6-0.8arcsec, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 70 239 K-band magnitude and structural parameters for
239 globular clusters (GCs) in M31
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See also:
J/A+A/471/127 : New globular clusters in M 31 (Galleti+, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Globular cluster name (1)
9- 15 F7.2 --- chi2/nu χ2 per degree of freedom for best
fitting model (2)
17- 20 F4.1 --- W0 Central potential depth
22- 25 F4.2 --- c Core concentration index (log(rt/rc))
27- 30 F4.1 mag Kmag K magnitude
32- 35 F4.2 pc rc Core radius (5)
37- 41 F5.2 pc rh Half-mass radius (5)
43- 47 F5.1 pc rt Total radius (5)
49- 53 F5.2 [solLum/pc3] logrhoc Central mass density
55- 59 F5.2 [-] logGamma Stellar collision rate
61- 67 A7 --- X X-ray source associated with GC flag (6)
69- 70 A2 --- Fl Flag based on residual (7)
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Note (1): Names from Galleti et al., 2007, Cat. J/A+A/471/127
Note (2): usually dominated by stars in GC frame.
Note (5): Assuming the distance of M31 to be 780kpc (McConnachie et al.,
2005MNRAS.356..979M 2005MNRAS.356..979M).
Note (6): X-ray source associated with GC flag:
0 = no source
S01 = Supper (2001, Cat. J/A+A/373/63), ROSAT
T04 = Trudolyubov (2004ApJ...616..821T 2004ApJ...616..821T), Chandra & XMM
Note (7): Flag as follows:
1 = good
2 = elliptical
3 = bad residual
4 = bright star in field
5 = asterism/no clear cluster
6 = unphysical parameters
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-May-2009