J/A+A/610/A64 Distance to the clouds in Chamaeleon complex (Voirin+, 2018)
A revised estimate of the distance to the clouds in the Chamaeleon complex
using the Tycho-Gaia Astrometric Solution.
Voirin J., Manara C.F., Prusti T.
<Astron. Astrophys. 610, A64 (2018)>
=2018A&A...610A..64V 2018A&A...610A..64V (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, distances ; Effective temperatures ;
Spectral types
Keywords: stars: distances - stars: formation - dust, extinction -
Galaxy: open clusters and associations: individual: Chamaeleon -
ISM: clouds
Abstract:
The determination of the distance to dark star-forming clouds is a key
parameter to derive the properties of the cloud itself, and of its
stellar content. This parameter is still loosely constrained even in
nearby star- forming regions.
We want to determine the distances to the clouds in the
Chamaeleon-Musca complex and to explore the connection between these
clouds and the large scale cloud structures in the galaxy.
We use the newly estimated distances obtained from the parallaxes
measured by the Gaia satellite and included in the Tycho-Gaia
Astrometric Solution catalog. When known members of a region are
included in this catalog we use their parallaxes to infer the distance
to the cloud. Otherwise, we analyze the dependence of the color excess
on the distance of the stars and look for a turn-on of this excess,
which is a proxy of the position of the front-edge of the star-forming
cloud.
We are able to measure the distance to the three Chamaeleon clouds.
The distance to Chamaeleon I is 179+11+11-10-10pc, where the
quoted uncertainties are statistical and systematic uncertainties,
respectively, 20 pc further away than previously assumed. The
Chamaeleon II cloud is located at the distance of 181+6+11-5-10pc,
which agrees with previous estimates. We are able to measure for the
first time a distance to the Chamaeleon III cloud of
199+8+12-7-11pc. Finally, the distance of the Musca cloud is
smaller than 603+91+133-70-92pc. These estimates do not allow us
to distinguish between the possibility that the Chamaeleon clouds are
part of a sheet of clouds parallel to the galactic plane, or
perpendicular to it.
We have measured a larger distance to the Chamaeleon I cloud than
assumed in the past, confirmed the distance to the Chamaeleon II
region, and measured for the first time the distance to the Chamaleon
III cloud. These values are consistent with the scenario where the
three clouds are part of a single large scale structure. Gaia Data
Release 2 will allow us to put more stringent constraints on the
distances to these clouds by giving us access to parallax measurements
for a larger number of members of these regions.
Description:
Catalog of stars on the line of sight of the Chamaeleon clouds used to
determine the reddening turn-on distance. Reported are the V and B
magnitudes, spectral types and/or effective temperatures, and their
distances.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 90 59 Catalog of stars on the line of sight of Cha I
table4.dat 89 44 Catalog of stars on the line of sight of Cha II
table5.dat 89 39 Catalog of stars on the line of sight of Cha III
table6.dat 89 76 Catalog of stars on the line of sight of Musca
--------------------------------------------------------------------------------
See also:
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/ApJ/833/119 : Distances of Gaia DR1 TGAS sources (Astraatmadja+, 2016)
Byte-by-byte Description of file: table3.dat table4.dat table5.dat table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Name of the field star
17- 26 F10.6 deg RAdeg Right ascension (ICRS) at epoch 2015.0
28- 37 F10.6 deg DEdeg Declination (ICRS) at epoch 2015.0
39- 43 F5.2 mag VTmag Tycho V-Band magnitude (1)
45- 49 F5.2 mag BTmag Tycho B-Band magnitude (1)
51- 58 A8 --- SpType Spectral type and luminosity class
60- 63 I4 K Teff ?=- Effective temperature
65- 70 F6.3 mag E(B-V) B-V colour excess
72- 76 F5.3 mag e_E(B-V) 1 sigma uncertainty on E(B-V)
78- 81 I4 pc Dist Distance from TGAS (2)
83- 86 I4 pc e_Dist Uncertainty on the distance from TGAS
88- 90 A3 --- Ref Reference for Sptype or Teff (3)
--------------------------------------------------------------------------------
Note (1): V and B magnitudes are taken from Tycho-2 catalog
(Hog et al., 2000A&A...355L..27H 2000A&A...355L..27H, Cat. I/259)
Note (2): The distances are taken from Astraatmadja & Bailer-jones
(2016ApJ...833..119A 2016ApJ...833..119A, Cat. J/ApJ/833/119) based on TGAS.
Note (3): References as follows:
A1 = spectral type from Houk & Cowley, 1975mcts.book.....H 1975mcts.book.....H, Cat. III/31
A2 = spectral type from Appenzeller, 1977A&A....61...21A 1977A&A....61...21A
A3 = spectral type from Vrba & Rydgren, 1984ApJ...283..123V 1984ApJ...283..123V
A4 = spectral type from Bastian & Roeser, 1993psc..book.....B 1993psc..book.....B, Cat. I/193
A5 = spectral type from Nesterov et al, 1995A&AS..110..367N 1995A&AS..110..367N, Cat. III/182
A6 = spectral type from Stoy & Jackson, 1964, 1996yCat.1116....0J 1996yCat.1116....0J, Cat. I/116
A7 = spectral type from Torres et al., 2006A&A...460..695T 2006A&A...460..695T, Cat. J/A+A/460/695
A8 = spectral type from Andersson et al, 2011A&A...534A..19A 2011A&A...534A..19A
A9 = temperature from Ammons et al., 2006ApJ...638.1004A 2006ApJ...638.1004A, Cat. V/136
A10 = temperature from Kordopatis et al., 2013AJ....146..134K 2013AJ....146..134K, Cat. III/272
B1 = spectral type from Houk & Cowley, 1975mcts.book.....H 1975mcts.book.....H, Cat. III/31
B2 = spectral type from Hughes & Hartigan, 1992AJ....104..680H 1992AJ....104..680H
B3 = spectral type from Bastian & Roeser, 1993psc..book.....B 1993psc..book.....B, Cat. I/193
B4 = spectral type from Stoy & Jackson, 1964, 1996yCat.1116....0J 1996yCat.1116....0J, Cat. I/116
B5 = temperature from Kordopatis et al., 2013AJ....146..134K 2013AJ....146..134K
C1 = spectral type from Houk & Cowley, 1975mcts.book.....H 1975mcts.book.....H, Cat. III/31
C2 = spectral type from Bastian & Roeser, 1993psc..book.....B 1993psc..book.....B, Cat. I/193
C3 = spectral type from Torres et al., 2006A&A...460..695T 2006A&A...460..695T, Cat. J/A+A/460/695
C4 = spectral type from Stoy & Jackson, 1964, 1996yCat.1116....0J 1996yCat.1116....0J, Cat. I/116
C5 = temperature from Ammons et al., 2006ApJ...638.1004A 2006ApJ...638.1004A., Cat. V/136
C6 = temperature from Kordopatis et al., 2013AJ....146..134K 2013AJ....146..134K
D1 = spectral type from Houk & Cowley, 1975mcts.book.....H 1975mcts.book.....H, Cat. III/31
D2 = temperature from Ammons et al., 2006ApJ...638.1004A 2006ApJ...638.1004A., Cat. V/136
D3 = temperature from Kordopatis et al., 2013AJ....146..134K 2013AJ....146..134K
--------------------------------------------------------------------------------
Acknowledgements:
Carlo Manara, cmanara(at)eso.org
(End) Patricia Vannier [CDS] 29-Nov-2017