J/MNRAS/477/2068 RV survey of the Carina Nebula's O stars (Kiminki+, 2018)
A radial velocity survey of the Carina Nebula's O-type stars.
Kiminki M.M., Smith N.
<Mon. Not. R. Astron. Soc. 477, 2068 (2018)>
=2018MNRAS.477.2068K 2018MNRAS.477.2068K (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Stars, O ; Radial velocities
Keywords: binaries: spectroscopic - stars: early-type -
stars: kinematics and dynamics - stars: massive - ISM: evolution -
open clusters and associations: individual: Carina Nebula
Abstract:
We have obtained multi-epoch observations of 31 O-type stars in the
Carina Nebula using the CHIRON spectrograph on the CTIO/SMARTS 1.5-m
telescope. We measure their radial velocities to 1-2 km/s precision
and present new or updated orbital solutions for the binary systems
HD 92607, HD 93576, HDE 303312, and HDE 305536. We also compile radial
velocities from the literature for 32 additional O-type and evolved
massive stars in the region. The combined data set shows a mean
heliocentric radial velocity of 0.6km/s. We calculate a velocity
dispersion of ≤9.1km/s, consistent with an unbound, substructured
OB association. The Tr 14 cluster shows a marginally significant 5km/s
radial velocity offset from its neighbour Tr 16, but there are
otherwise no correlations between stellar position and velocity. The
O-type stars in Cr 228 and the South Pillars region have a lower
velocity dispersion than the region as a whole, supporting a model of
distributed massive star formation rather than migration from the
central clusters. We compare our stellar velocities to the Carina
Nebula's molecular gas and find that Tr 14 shows a close kinematic
association with the Northern Cloud. In contrast, Tr 16 has
accelerated the Southern Cloud by 10-15km/s, possibly triggering
further massive star formation. The expansion of the surrounding H II
region is not symmetric about the O-type stars in radial velocity
space, indicating that the ionized gas is constrained by denser
material on the far side.
Description:
Heliocentric radial velocities of 31 O-type stars in the Carina
Nebula, measured from fiber-mode observations with the CHIRON
spectrograph on the CTIO/SMARTS 1.5-m telescope. Dates are given for
the midpoints of the exposures.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 40 31 List of studied stars
table2.dat 52 145 CHIRON radial velocities
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See also:
II/82 : Galactic O-type Stars (Garmany+ 1982)
J/A+A/549/A67 : Embedded YSOs in Carina Nebula complex (Gaczkowski+, 2013)
J/A+A/567/A109 : Carina nebula optically identified YSOs (Kumar+, 2014)
J/A+A/603/A81 : Trumpler 14 and 16 in the Carina nebula (Damiani+, 2017)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Star name used in the Galactic O-Star Catalog
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 25 F5.2 s RAs Right ascension (J2000)
27 A1 --- DE- Declination sign (J2000)
28- 29 I2 deg DEd Declination (J2000)
31- 32 I2 arcmin DEm Declination (J2000)
34- 38 F5.2 arcsec DEs Declination (J2000)
39- 40 I2 --- N Number of radial velocity measurements in table2
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Star name used in the Galactic O-Star Catalog
16- 24 F9.3 d HJD Heliocentric Julian date (HJD-2400000)
at midpoint of exposure
27- 32 F6.1 km/s RV1 Radial velocity of primary star
35- 38 F4.1 km/s e_RV1 One-sigma uncertainty on RV1
41- 46 F6.1 km/s RV2 ? Radial velocity of secondary star
(where present)
49- 52 F4.1 km/s e_RV2 ? One-sigma uncertainty on RV2
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Acknowledgements:
Megan M. Kiminki, mbagley(at)email.arizona.edu
(End) Megan M. Kiminki [Univ. of Arizona], Patricia Vannier [CDS] 18-Jun-2018