eprintid: 1499866
rev_number: 30
eprint_status: archive
userid: 608
dir: disk0/01/49/98/66
datestamp: 2016-06-19 00:33:25
lastmod: 2021-10-10 22:51:02
status_changed: 2018-01-04 14:38:57
type: article
metadata_visibility: show
creators_name: Howarth, ID
creators_name: Dufton, PL
creators_name: Dunstall, PR
creators_name: Evans, CJ
creators_name: Almeida, LA
creators_name: Bonanos, AZ
creators_name: Clark, JS
creators_name: Langer, N
creators_name: Sana, H
creators_name: Simon-Diaz, S
creators_name: Soszynski, I
creators_name: Taylor, WD
title: The VLT-FLAMES Tarantula Survey XXIII. Two massive double-lined binaries in 30 Doradus
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F60
keywords: stars: early-type – binaries: spectroscopic – stars: variable: general – stars: fundamental parameters – stars:
individual (VFTS 450, VFTS 652)
note: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: Aims. We investigate the characteristics of two newly discovered short-period, double-lined, massive binary systems in the Large
Magellanic Cloud, VFTS 450 (O9.7 II–Ib + O7::) and VFTS 652 (B1 Ib + O9: III:).
Methods. We perform model-atmosphere analyses to characterise the photospheric properties of both members of each binary (denoting
the “primary” as the spectroscopically more conspicuous component). Radial velocities and optical photometry are used to
estimate the binary-system parameters.
Results. We estimate Teff = 27 kK, log g = 2.9 (cgs) for the VFTS 450 primary spectrum (34 kK, 3.6: for the secondary spectrum);
and Teff = 22 kK, log g = 2.8 for the VFTS 652 primary spectrum (35 kK, 3.7: for the secondary spectrum). Both primaries show
surface nitrogen enrichments (of more than 1 dex for VFTS 652), and probable moderate oxygen depletions relative to reference
LMC abundances. We determine orbital periods of 6.89 d and 8.59 d for VFTS 450 and VFTS 652, respectively, and argue that
the primaries must be close to filling their Roche lobes. Supposing this to be the case, we estimate component masses in the range
∼20–50 M�.
Conclusions. The secondary spectra are associated with the more massive components, suggesting that both systems are high-mass
analogues of classical Algol systems, undergoing case-A mass transfer. Difficulties in reconciling the spectroscopic analyses with the
light-curves and with evolutionary considerations suggest that the secondary spectra are contaminated by (or arise in) accretion disks.
date: 2015-10-01
date_type: published
publisher: EDP SCIENCES S A
official_url: http://doi.org/10.1051/0004-6361/201526408
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1093759
doi: 10.1051/0004-6361/201526408
lyricists_name: Howarth, Ian
lyricists_id: IDHOW62
actors_name: Waragoda Vitharana, Nimal
actors_id: NWARR44
actors_role: owner
full_text_status: public
publication: Astronomy & Astrophysics
volume: 582
number: A73
pages: 19
issn: 1432-0746
citation:        Howarth, ID;    Dufton, PL;    Dunstall, PR;    Evans, CJ;    Almeida, LA;    Bonanos, AZ;    Clark, JS;                     ... Taylor, WD; + view all <#>        Howarth, ID;  Dufton, PL;  Dunstall, PR;  Evans, CJ;  Almeida, LA;  Bonanos, AZ;  Clark, JS;  Langer, N;  Sana, H;  Simon-Diaz, S;  Soszynski, I;  Taylor, WD;   - view fewer <#>    (2015)    The VLT-FLAMES Tarantula Survey XXIII. Two massive double-lined binaries in 30 Doradus.                   Astronomy & Astrophysics , 582  (A73)      10.1051/0004-6361/201526408 <https://doi.org/10.1051/0004-6361%2F201526408>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1499866/1/Howarth_aa26408-15.pdf