J/PASP/132/E4301 Catalog of Infrared Dark Clouds (Pari+, 2020)
A semi-automated computational approach for Infrared Dark cloud localization:
a catalog of Infrared Dark Clouds.
Pari J., Hora J.L.
<Publ. Astron. Soc. Pac., 132, e4301 (2020)>
=2020PASP..132e4301P 2020PASP..132e4301P (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Infrared sources ; Morphology
Abstract:
The field of computer vision has greatly matured in the past decade,
and many of the methods and techniques can be useful for astronomical
applications. One example is in searching large imaging surveys for
objects of interest, especially when it is difficult to specify the
characteristics of the objects being searched for. We have developed a
method using contour finding and convolution neural networks (CNNs) to
search for Infrared Dark Clouds (IRDCs) in the Spitzer Galactic plane
survey data. IRDCs can vary in size, shape, orientation, and optical
depth, and are often located near regions with complex emission from
molecular clouds and star formation, which can make the IRDCs
difficult to reliably identify. False positives can occur in regions
where emission is absent, rather than from a foreground IRDC. The
contour finding algorithm we implemented found most closed figures in
the mosaic and we developed rules to filter out some of the false
positive before allowing the CNNs to analyze them. The method was
applied to the Spitzer data in the Galactic plane surveys, and we have
constructed a catalog of IRDCs which includes additional parts of the
Galactic plane that were not included in earlier surveys.
Description:
The mosaics used here are based on images obtained with the IRAC
instrument on Spitzer. We used the mosaic images created by the
GLIMPSE team for the GLIMPSE and other surveys conducted during the
Spitzer mission.
we find a total of 18845 objects that should be considered as
candidate IRDCs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 65 18845 IRDC Catalog
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See also:
J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name IRDC name, GLLL.ll+BB.bbb)
16- 23 F8.4 deg GLON Galactic longitude
25- 31 F7.4 deg GLAT Galactic latitude
33- 38 F6.1 arcsec Size(GLON) Size (GLON)
40- 44 F5.1 arcsec Size(GLAT) Size (GLAT)
46- 49 F4.2 --- DepthRatio Depth ratio (1)
51- 54 F4.2 --- Prob Probability of IRDC
56- 61 I6 --- Area Contour Area of IRDC
63- 65 I3 --- PF09 [0/28]?=999 Number of PF09 objects
inside IRDC (2)
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Note (1): difference between the median 3.6um flux density around the outside of
the IRDC box and the non-negative minimum level of a pixel within the box
divided by the median outside of the box.
Note (2): The PF09 value gives the number of IRDCs in the Peretto & Fuller
(2009A&A...505..405P 2009A&A...505..405P, Cat. J/A+A/505/405) catalog are within the IRDC in this
catalog. A Null value (999) means that the object is outside the region
surveyed by PF09.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Oct-2020