J/A+A/633/A51 Distances to molecular clouds in SFR (Zucker+, 2020)
A compendium of distances to molecular clouds in the Star Formation Handbook.
Zucker C., Speagle J.S., Schlafly E., Green G.M., Finkbeiner D.P.,
Goodman A., Alves J.
<Astron. Astrophys. 633, A51 (2020)>
=2020A&A...633A..51Z 2020A&A...633A..51Z (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Stars, distances
Keywords: local insterstellar matter - solar neighborhood - catalog
Abstract:
Accurate distances to local molecular clouds are critical for
understanding the star and planet formation process, yet distance
measurements are often obtained inhomogeneously on a cloud-by-cloud
basis. We have recently developed a method which combines stellar
photometric data with Gaia DR2 parallax measurements in a Bayesian
framework to infer the distances of nearby dust clouds to a typical
accuracy of ∼5%. After refining the technique to target lower
latitudes and incorporating deep optical data from DECam in the
southern Galactic plane, we have derived a catalog of distances to
molecular clouds in Reipurth (2008, Star Formation Handbook, vols I
and II) which contains a large fraction of the molecular material in
the solar neighborhood. Comparison with distances derived from maser
parallax measurements towards the same clouds shows our method
produces consistent distances with <10% scatter for clouds across our
entire distance spectrum (150pc-2.5kpc). We hope this catalog of
homogeneous distances will serve as a baseline for future work.
Description:
Distances to ∼60 star-forming regions in Reipurth (2008, Star
Formation Handbook, vols I and II) have been computed using stellar
photometry and Gaia DR2 parallax measurements. Usually, several
distance estimates are taken across each cloud.
For each sightline, the median distance (d50) is provided, plus the
16th and 84th percentiles on the distance probability distribution
function. There is an additional systematic uncertainty, which is
unknown but estimated to be ∼5% in distance for clouds <1.5kpc, ∼10%
in distance for clouds >1.5kpc, and ∼7% in distance for the southern
clouds Lupus, Chamaeleon, and Corona Australis. These should be added
in quadrature with the statistical uncertainties reported in the
table. In addition to the distances, ancillary model parameters used
in our fit are also included (e.g. the amount of foreground extinction
"f"). See Section 3.2.1 and Section 3.2.2 in Zucker et al.
(2019ApJ...879..125Z 2019ApJ...879..125Z) for a complete description of model parameters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
handbook.dat 175 326 Star Formation Handbook Cloud Distances (table A1)
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Byte-by-byte Description of file: handbook.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Name Cloud/star-forming region associated with
sightline
19- 23 F5.1 deg GLON Galactic longitude of center of sightline
25- 29 F5.1 deg GLAT Galactic latitude of center of sightline
31- 36 F6.4 --- n16 16th percentile of the samples for the
normalization factor parameter N
38- 43 F6.4 --- n50 50th percentile of the samples for the
normalization factor parameter N
45- 50 F6.4 --- n84 84th percentile of the samples for the
normalization factor parameter N
52- 57 F6.4 mag f16 16th percentile of the samples for the
foreground extinction parameter f
59- 64 F6.4 mag f50 50th percentile of the samples for the
foreground extinction parameter f
66- 71 F6.4 mag f84 84th percentile of the samples for the
foreground extinction parameter f
73- 79 F7.4 mag m16 16th percentile of the samples for the cloud
distance modulus mu_c
81- 87 F7.4 mag m50 50th percentile of the samples for the cloud
distance modulus mu_c
89- 95 F7.4 mag m84 84th percentile of the samples for the cloud
distance modulus mu_c
97-100 I4 pc d16 16th percentile of the samples for the cloud
distance D_c
102-105 I4 pc d50 50th percentile of the samples for the cloud
distance D_c
107-110 I4 pc d84 84th percentile of the samples for the cloud
distance D_c
112-117 F6.4 --- p16 16th percentile of the samples for the
fraction of outlier stars Pb
119-124 F6.4 --- p50 50th percentile of the samples for the
fraction of outlier stars Pb
126-131 F6.4 --- p84 84th percentile of the samples for the
fraction of outlier stars Pb
133-138 F6.4 --- sfore16 16th percentile of the samples for the
foreground smoothing parameter sfore
140-145 F6.4 --- sfore50 50th percentile of the samples for the
foreground smoothing parameter sfore
147-152 F6.4 --- sfore84 84th percentile of the samples for the
foreground smoothing parameter sfore
154-159 F6.4 --- sback16 16th percentile of the samples for the
background smoothing parameter sback
161-166 F6.4 --- sback50 50th percentile of the samples for the
background smoothing parameter sback
168-173 F6.4 --- sback84 84th percentile of the samples for the
background smoothing parameter sback
175 I1 --- new [0/1]? Whether the sightline is novel to this
work (1), or taken from Zucker et al.
2019ApJ...879..125Z 2019ApJ...879..125Z (0) (1)
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Note (1): Flag as follows:
1 = sightline is novel to this work
0 = taken from Zucker et al., 2019ApJ...879..125Z 2019ApJ...879..125Z
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Acknowledgements:
Catherine Zucker, catherine.zucker(at)cfa.harvard.edu
(End) Patricia Vannier [CDS] 13-Sep-2019