J/MNRAS/516/1289 Gaia-EDR3 distance to the Wd1 Complex (Navarete+, 2022)
Distance and age of the massive stellar cluster Westerlund 1.
I. Parallax method using Gaia-EDR3.
Navarete F., Damineli A., Ramirez A.E., Rocha D.F., Almeida L.A.
<Mon. Not. R. Astron. Soc. 516, 1289 (2022)>
=2022MNRAS.516.1289N 2022MNRAS.516.1289N (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Parallaxes, trigonometric ; Proper motions
Keywords: parallaxes - stars: distances - stars: supergiants -
stars: Wolf-Rayet -
open clusters and associations: individual: Westerlund 1
Abstract:
Westerlund 1 (Wd 1) is one of the most massive young star clusters in
the Milky Way. Although relevant for star formation and evolution, its
fundamental parameters are not yet very well constrained. We aim to
derive an accurate distance and provide constraints on the cluster
age. We used the photometric and astrometric information available in
the Gaia Early Data Release 3 (Gaia-EDR3) to infer its distance of
4.06+0.36-0.34kpc. Modelling of the eclipsing binary system W36,
reported in Paper II (Rocha et al., 2022, in prep.), led to the
distance of 4.03±0.25kpc, in agreement with the Gaia-EDR3 distance
and, therefore, validating the parallax zero-point correction approach
appropriate for red objects. The weighted average distance based on
these two methods results in dwd1=4.05±0.20kpc
(m-M=13.04+0.11-0.12mag), which has an unprecedented accuracy of
5%. Using the Binary Population and Spectral Synthesis (BPASS) models
for the Red Supergiants with solar abundance, we derived an age of
10.7±1Myr, in excellent agreement with recent work by Beasor et al.
(2021ApJ...912...16B 2021ApJ...912...16B) (10.4+1.3-1.2Myr) based on MIST evolutionary
models. In Paper II, the age of W36B was reported to be 6.4±0.5Myr,
supporting recent claims of a temporal spread of several Myrs for the
star-forming process within Wd1 instead of a single monolithic
starburst episode scenario.
Description:
The identification of cluster members in the Gaia-EDR3 catalogue was
performed in two steps. First, we identified each member in one of the
few catalogues which have been cross-matched with GAIA-DR3, such as
the Guide Star Catalog II Lasker et al. (GSC-II, 2008, Cat. I/305) in
visible wavelengths, and the Two Micron All Sky Survey Skrutskie et
al. (2MASS, 2006, Cat. VII/233/) in the near-infrared.
Then, we cross-matched the GSC-II IDs with the gsc23bestneighbour
table of the Gaia-EDR3 catalogue, and the 2MASS IDs with the
tmassbestneighbour table. The positions of 166 stellar members of
Westerlund 1 reported by Clark et al. (2020A&A...635A.187C 2020A&A...635A.187C, Cat.
J/A+A/635/A187) were crossmatched with the GSC-II and the 2MASS
catalogues (assuming a maximum offset of 100), resulting in a list of
85 sources with a 2MASS counterpart and 105 sources with a GSC
counterpart.
Then, the lists were cross-matched with the Gaia-EDR3, leading
to a final list with 166 Wd1 members associated with a Gaia-EDR3
counterpart, from which 67 corresponds to 5-p sources (listed in Table
A1), 30 sources are 6-p (Table A2), and 69 have Gaia-EDR3 counterparts
with no astrometric information. These last 16 objects were merged
with 60 other Wd1 members with no Gaia-EDR3 counterparts (Table A3).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 63 10 Classification, photometry, reddening and
bolometric luminosities for the
Red Supergiants and Yellow Hypergiants
tablea1.dat 136 67 List of known Westerlund 1 members with Gaia EDR3
counterparts associated with a 5-parameter
astrometric solution (5-p)
tablea2.dat 136 30 List of known Westerlund 1 members with Gaia-EDR3
counterparts associated with a 6-parameter
astrometric solution (6-p)
tablea3.dat 53 69 List of known Westerlund 1 members with
no astrometric information
--------------------------------------------------------------------------------
See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
J/A+A/635/A187 : Massive binaries in Westerlund 1. VII. (Clark+, 2020)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Name Name of the source (G1)
7- 9 A3 --- Class Classification of the source (RSG/YHG)
11- 18 A8 --- SpType Spectral Type classification
20- 23 F4.2 [K] logTeff ?=- logarithm of the Effective temperature
25- 28 F4.2 mag Jmag Apparent magnitude in J band
30- 33 F4.2 mag Hmag Apparent magnitude in H band
35- 38 F4.2 mag Ksmag Apparent magnitude in Ks band
40- 43 F4.2 mag AKs Extinction at the Ks-band
45- 48 F4.2 mag e_AKs Error of AKs
50- 53 F4.2 [Lsun] logLbol logarithm of the Bolometric luminosity
55- 58 F4.2 [Lsun] e_logLbol logarithm of the Bolometric luminosity error
60- 63 F4.2 [Lsun] logLbolB21 logarithm of the Bolometric luminosity
from Beasor et al., (2021ApJ...912...16B 2021ApJ...912...16B)
scaled to the distance of Wd1 )
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Name Name of the source (G1)
7- 16 A10 --- GSC GSC designation
18- 33 A16 --- 2MASS 2MASS designation
35- 53 I19 --- GaiaEDR3 Gaia-EDR3 designation
55- 58 F4.2 --- RUWE Renormalized Unit Weight Error
60- 65 F6.3 mas plx ?=- Parallax from Gaia EDR3
67- 72 F6.3 mas e_plx ?=- Parallax error from Gaia EDR3
74- 79 F6.3 mas zp-plx ?=- Parallax zero-point correction
81- 87 F7.3 mas/yr pmRA Proper motion in RA direction
89- 94 F6.3 mas/yr e_pmRA Proper motion error on RA direction
96-102 F7.3 mas/yr pmDE Proper motion in Dec direction
104-109 F6.3 mas/yr e_pmDE Proper motion error on Dec direction
111-115 F5.3 um-1 nueff Effective wavenumber
117-121 F5.1 --- minphoter Minimum photometric error on the G, BP and RP
bands (in standard deviation units)
123-126 F4.1 mag Gmag ?=- Apparent magnitude in G band
128-131 F4.1 mag BPmag ?=- Apparent magnitude in BP band
133-136 F4.1 mag RPmag ?=- Apparent magnitude in RP band
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Name Name of the source (G1)
7- 16 A10 --- GSC GSC designation
18- 33 A16 --- 2MASS 2MASS designation
35- 53 I19 --- GaiaEDR3 Gaia-EDR3 designation
55- 58 F4.2 --- RUWE Renormalized Unit Weight Error
60- 65 F6.3 mas plx ?=- Parallax from Gaia EDR3
67- 72 F6.3 mas e_plx ?=- Parallax error from Gaia EDR3
74- 79 F6.3 mas zp-plx ?=- Parallax zero-point correction
81- 87 F7.3 mas/yr pmRA Proper motion in RA direction
89- 94 F6.3 mas/yr e_pmRA Proper motion error on RA direction
96-102 F7.3 mas/yr pmDE Proper motion in Dec direction
104-109 F6.3 mas/yr e_pmDE Proper motion error on Dec direction
111-115 F5.3 um-1 pseudo Pseudo-colour (in the Gaia catalogue)
117-121 F5.1 --- minphoter Minimum photometric error on the G, BP and RP
bands (in standard deviation units)
123-126 F4.1 mag Gmag ?=- Apparent magnitude in G band
128-131 F4.1 mag BPmag ?=- Apparent magnitude in BP band
133-136 F4.1 mag RPmag ?=- Apparent magnitude in RP band
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Name Name of the source (G1)
7- 16 A10 --- GSC GSC designation
18- 33 A16 --- 2MASS 2MASS designation
35- 53 I19 --- GaiaEDR3 ?=- Gaia-EDR3 designation
--------------------------------------------------------------------------------
Global notes:
Note (G1): Names for Clark et al., 2020A&A...635A.187C 2020A&A...635A.187C, Cat. J/A+A/635/A187,
WNNNa are Cl* Westerlund 1 W NNNa in Simbad,
WRA are Cl* Westerlund 1 CN A in Simbad,
NNNN are [CRN2020] WNNNN in Simbad
--------------------------------------------------------------------------------
Acknowledgements:
Felipe Navarete, navarete(at)gmail.com
(End) Patricia Vannier [CDS] 04-Oct-2022