J/MNRAS/436/1465 Star clusters distances and extinctions (Buckner+, 2013)
Properties of star clusters. I. Automatic distance and extinction estimates.
Buckner A.S.M., Froebrich D.
<Mon. Not. R. Astron. Soc., 436, 1465-1478 (2013)>
=2013MNRAS.436.1465B 2013MNRAS.436.1465B
ADC_Keywords: Associations, stellar ; Clusters, open ; Stars, distances ;
Extinction
Keywords: stars: distances - stars: fundamental parameters - stars: statistics -
dust, extinction - open clusters and associations: general
galaxies: star clusters: general
Abstract:
Determining star cluster distances is essential to analyse their
properties and distribution in the Galaxy. In particular, it is
desirable to have a reliable, purely photometric distance estimation
method for large samples of newly discovered cluster candidates e.g.
from the Two Micron All Sky Survey, the UK Infrared Deep Sky Survey
Galactic Plane Survey and VVV. Here, we establish an automatic method
to estimate distances and reddening from near-infrared photometry
alone, without the use of isochrone fitting. We employ a
decontamination procedure of JHK photometry to determine the density
of stars foreground to clusters and a galactic model to estimate
distances. We then calibrate the method using clusters with known
properties. This allows us to establish distance estimates with better
than 40 percent accuracy.
We apply our method to determine the extinction and distance values to
378 known open clusters and 397 cluster candidates from the list of
Froebrich, Scholz & Raftery (2007MNRAS.374..399F 2007MNRAS.374..399F, Cat.
J/MNRAS/374/399). We find that the sample is biased towards clusters
of a distance of approximately 3kpc, with typical distances between 2
and 6kpc. Using the cluster distances and extinction values, we
investigate how the average extinction per kiloparsec distance changes
as a function of the Galactic longitude. We find a systematic
dependence that can be approximated by
AH(l)[mag/kpc]=0.10+0.001x|l-180°|/° for regions more than
60° from the Galactic Centre.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 76 775 Summary table of the FSR cluster properties
determined with our method
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See also:
J/MNRAS/374/399 : Infrared star clusters with |b|<20° (Froebrich+, 2007)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- FSR [1/1785] FSR ID number (Froebrich, Scholz and
Raftery 2007, J/MNRAS/374/399;
<[FSR2007] NNNN> in Simbad)
6- 10 A5 --- Type [new/known ] known open cluster or
new open cluster candidate
12- 17 F6.2 deg GLON Galactic longitude
19- 24 F6.2 deg GLAT Galactic latitude
26- 27 I2 h RAh Right ascension (J2000)
29- 30 I2 min RAm Right ascension (J2000)
32- 35 F4.1 s RAs Right ascension (J2000)
37 A1 --- DE- Declination sign (J2000)
38- 39 I2 deg DEd Declination (J2000)
41- 42 I2 arcmin DEm Declination (J2000)
44- 45 I2 arcsec DEs [0/60] Declination (J2000)
47- 50 F4.1 kpc Dist ?=- Distance
52- 56 F5.2 mag AH4.5 H-band extinction values calculated from
H-[4.5] excess
58- 62 F5.2 mag AH.K H-band extinction values calculated from
H-K excess
64- 67 F4.2 --- YSO [0/0.15] YSO fraction
69- 72 I4 --- Ntot Number of stars within two core radii of
the cluster centre (Ntot2rcore)
74- 76 I3 --- Nmem Total number of members (calculated as the
sum of the membership probabilities of all
stars) in the same area (Nmem2rcore)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 22-Oct-2014