J/MNRAS/486/1034 O stars of the Galactic starburst NGC 3603 (Drew+, 2019)
The O star hinterland of the Galactic starburst, NGC 3603.
Drew J.E., Monguio M., Wright N.J.
<Mon. Not. R. Astron. Soc., 486, 1034-1044 (2019)>
=2019MNRAS.486.1034D 2019MNRAS.486.1034D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, O ; Stars, early-type ; Clusters, open ; Positional data ;
Proper motions ; Effective temperatures ; Optical
Keywords: proper motions - stars: early-type - stars: massive -
open clusters and associations: individual: NGC 3603
Abstract:
The very bright and compact massive young cluster, NGC 3603, has been
cited as an example of a starburst in the Milky Way and compared with
the much-studied R136/30 Doradus region in the Large Magellanic Cloud.
Here we build on the discovery by Mohr-Smith et al. of a large number
of reddened O stars around this cluster. We construct a list of 288
candidate O stars with proper motions (PMs), in a region of sky
spanning 1.5x1.5deg2 centred on NGC 3603, by cross-matching the
Mohr-Smith et al. catalogue with Gaia DR2. This provides the basis for
a first comprehensive examination of the PMs of these massive stars in
the halo of NGC 3603, relative to the much better studied central
region. We identify up to 11 likely O star ejections - 8 of which
would have been ejected between 0.60 and 0.95Myr ago (supporting the
age of ∼1Myr that has been attributed to the bright cluster centre).
Seven candidate ejections are arranged in a partial ring to the south
of the cluster core spanning radii of 9-18arcmin (18-36pc if the
cluster is 7kpc away). We also show that the cluster has a halo of a
further ∼100 O stars extending to a radius of at least 5arcmin, adding
to the picture of NGC 3603 as a scaled down version of the R136/30 Dor
region.
Description:
We adopt as the central reference position in the core of NGC 3603 the
Galactic coordinates, l=291.617°,b=-0.523°. The selection box
on the sky around this position is a square occupying 1.5x1.5deg2,
with sides oriented along the directions of constant Galactic
longitude and latitude. Within this region, the MS-II data base
(Mohr-Smith et al. 2017MNRAS.465.1807M 2017MNRAS.465.1807M, Cat. J/MNRAS/465/1807)
provides a list of 1663 blue-selected OB candidate stars. Of these we
retain as a long list those objects for which the reported quality of
fits to their optical-NIR SEDs is χ2<25. MS-II recommended a
tighter χ2 limit than this for the selection of 'good OB stars':
it is relaxed here so as not to exclude detected objects close to the
centre of NGC 3603 that are known already to be early-type
emission-line stars. This reduces the list to 1537 objects.
After selecting the stars with log(Teff)>4.44 and Kmag<13.0, we
cross-matched this sample with Gaia DR2 (Gaia Collaboration
2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345). Then, after applying some quality
filters based on the Gaia DR2 documentation, we obtained a sample of
288 candidate O stars of which 15 are already in the literature. Table
B1 lists the names, positions, and other important quantities of our
sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 113 288 Complete sample of 288 candidate O stars
obtained by cross-matching MS-II and Gaia DR2
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/MNRAS/465/1807 : Deep OB star population in Carina (Mohr-Smith+, 2017)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name MS-II object identifier (NNNNN) (1)
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 30 F5.2 arcsec DEs Declination (J2000)
32- 35 F4.2 [K] logTeff Logarith of the effective temperature (1)
37- 40 F4.2 mag A0 Monochromatic extinction at 5495Å (1)
42- 60 I19 --- GaiaDR2 Gaia DR2 source identifier
62- 69 F8.5 mas plx Parallax
71- 75 F5.2 mag Gmag Gaia DR2 G-band magnitude
77- 81 F5.2 arcsec Radius Angular distance from the adopted cluster
centre, at (l=291.617°,b=-0.523°)
83- 88 F6.3 mas/yr rpmGLON Relative proper motion in galactic longitude
relative to the core-region mean
90- 95 F6.3 mas/yr rpmGLAT Relative proper motion in galactic latitude
relative to the core-region mean
97-101 F5.3 mas/yr rpm Total relative proper motion magnitude
103-107 F5.2 arcmin IP Trajectory impact parameter
109-113 F5.2 arcmin e_IP Error on IP
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Note (1): Values from Mohr-Smith et al. (2017MNRAS.465.1807M 2017MNRAS.465.1807M,
Cat. J/MNRAS/465/1807)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 21-Oct-2022