J/PASJ/63/S1 Atlas and catalog of dark clouds based on 2MASS (Dobashi+, 2011)
Atlas and catalog of dark clouds based on the 2 Micron All Sky Survey.
Dobashi K.
<Publ. Astron. Soc. Jap., 63, S1-S362 (2011)>
=2011PASJ...63S...1D 2011PASJ...63S...1D
ADC_Keywords: Molecular clouds; Extinction; Interstellar medium ;
Infrared sources
Keywords: atlas - catalog - ISM: cloud - ISM: dust - ISM: extinction
Abstract:
This paper presents an atlas and catalog of dark clouds derived based
on the 2 Micron All Sky Survey Point Source Catalog (2MASS PSC). Color
excess maps of E(J-H) and E(H-KS) as well as extinction maps of
AJ, AH, and AKS_ covering all of the sky have been produced at
the 1' grid with a changing angular resolution (∼1'-12'), depending on
the regions in the sky. Maps drawn at the lower 15' grid with a fixed
1° resolution were also derived for various sets of threshold
magnitudes in the J, H, and KS bands to estimate the background star
colors and star densities needed to derive the color excess and
extinction maps. The maps obtained in this work are presented on
various scales in a series of figures that can be used as an atlas of
dark clouds for general research purposes. On the basis of the E(J-H)
and AJ maps drawn at the 1' grid, we have carried out a systematic
survey for dark clouds all over the sky. In total, we identified 7614
dark clouds, and measured the coordinates, extents, and AV values
for each of them. We also searched for their counterparts in a
previously published catalog of dark clouds based on the optical
photographic plates DSS (Dobashi et al., 2005PASJ...57S...1D 2005PASJ...57S...1D, Cat.
VII/244). These cloud parameters, including the information of the
counterparts, are compiled into a new catalog of dark clouds.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table8.dat 70 7614 Catalog of dark clouds
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
VII/244 : Atlas and Catalog of Dark Clouds (Dobashi+, 2005)
Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/7614] Sequential number
6- 8 I3 deg GLONd Galactic longitude of cloud peak position
10- 11 I2 arcmin GLONm Galactic longitude of cloud peak position
13 A1 --- GLAT- Galactic latitude sign
14- 15 I2 deg GLATd Galactic latitude of cloud peak position
17- 18 I2 arcmin GLATm Galactic latitude of cloud peak position
20- 26 F7.2 arcmin2 Area Surface area
28- 32 F5.2 mag AV Core absorption in V-band at the peak
position
34- 37 F4.2 mag e_AV rms uncertainty on AV
39- 46 F8.2 mag.arcmin2 IAVds Core absorption integrated over the
cloud surface
48- 51 F4.2 mag.arcmin2 e_IAVds rms uncertainty on IAVds
53 A1 --- Q [A-C] Rank of reliability in detection
(A=best) (1)
55- 61 A7 --- Flag Notes about cloud (2)
63- 70 A8 --- TGU Cloud numbers in the catalog by Dobashi et
al. (2005, Cat. VII/244 ) (3)
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Note (1): Rank as follows:
A = Clouds having a counterpart in one or more other databases,
ensuring that the cloud is real (350 clouds)
B = Clouds falling in the outskirts of the distribution of dense gas
or dust found in other databases, and their counterpart cannot
be identified clearly (210 clouds, some of them might be fake)
C = Clouds heavily affected by bright stars in the vicinity, and
cloud parameters such as AV cannot be measured reliably
(54 clouds , some of them might be fake)
Note (2): Flag of one or more integer numbers as follows:
0 = Clouds originating from the E(J-H)Xm50 map (5255 clouds)
1 = Clouds originating from the AJ map (2359 clouds)
2 = Distant clouds appearing as a hole in the E(J-H)Xm50 map,
but as a bump in the AJ map (Sect. 6.6) (747 clouds)
3 = Clouds possibly contaminated by IR clusters appearing as a hole
in the AJ map, but as a bump in the E(J-H)Xm50 map
(Sect. 6.4) (543 clouds)
4 = Clouds found in the vicinity of bright stars in the SAO catalog
(≲6mag), which may affect our estimate of AV (15 clouds)
5 = Clouds found in the vicinity of bright stars in the 2MASS PSC
(≤5mag either in J, H, or KS bands), which may affect our
estimates of AV (40 clouds)
6 = Clouds found within the radii of globular clusters catalogued by
Monella (1985, Coelum, 53, 287), which may affect our estimates
of AV (only 1 cloud)
7 = Clouds found in the radii of open clusters catalogued by Dias
et al. (2002A&A...389..871D 2002A&A...389..871D, Cat. B/ocl), which may affect our
estimates of AV (48 clouds)
8 = Clouds in M 31 and M 33 (Sect. 6.7) (15 clouds)
Note (3): If the clouds found in this work fall within the cloud extents in
their catalog, the corresponding cloud numbers are listed in this
column. There are 6516 clouds whose counterparts are found in their
catalog. Note that the TGU numbers given in this column merely denote
the coincidence, which does not ensure a definite physical
association.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Aug-2011