J/A+A/690/A289 Binarity at LOw Metallicity (BLOeM). I. (Shenar+, 2024)
Binarity at LOw Metallicity (BLOeM).
I. A spectroscopic VLT monitoring survey of massive stars in the SMC.
Shenar T., Bodensteiner J., Sana H., Crowther P.A., Lennon D.J.,
Abdul-Masih M., Almeida L.A., Backs F., Berlanas S.R., Bernini-Peron M.,
Bestenlehner J.M., Bowman D.M., Bronner V.A., Britavskiy N., de Koter A.,
de Mink S.E., Deshmukh K., Evans C.J., Fabry M., Gieles M., Gilkis A.,
Gonzalez-Tora G., Graefener G., Goetberg Y., Hawcroft C., Henault-Brunet V.,
Herrero A., Holgado G., Janssens S., Johnston C., Josiek J., Justham S.,
Kalari V.M., Katabi Z.Z., Keszthelyi Z., Klencki J., Kubat J., Kubatova B.,
Langer N., Lefever R.R., Ludwig B., Mackey J., Mahy L., Maiz Apellaniz J.,
Mandel I., Maravelias G., Marchant P., Menon A., Najarro F., Oskinova L.M.,
O'Grady A.J.G., Ovadia R., Patrick L.R., Pauli D., Pawlak M.,
Ramachandran V., Renzo M., Rocha D.F., Sander A.A.C., Sayada T.,
Schneider F.R.N., Schootemeijer A., Schoesser E.C., Schuermann C., Sen K.,
Shahaf S., Simon-Diaz S., Stoop M., Toonen S., Tramper F., van Loon J.T.,
Valli R., van Son L.A.C., Vigna-Gomez A., Villasenor J.I., Vink J.S.,
Wang C., Willcox R.
<Astron. Astrophys. 690, A289 (2024)>
=2024A&A...690A.289S 2024A&A...690A.289S (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Populations, stellar ; Photometry, infrared ;
MK spectral classification
Keywords: binaries: general - binaries: spectroscopic - stars: massive -
Magellanic Clouds
Abstract:
Surveys in the Milky Way and Large Magellanic Cloud have revealed that
the majority of massive stars will interact with companions during
their lives. However, knowledge of the binary properties of massive
stars at low metallicity, and therefore in conditions approaching
those of the Early Universe, remain sparse. We present the Binarity at
LOw Metallicity (BLOeM) campaign, an ESO large programme designed to
obtain 25 epochs of spectroscopy for 929 massive stars in the Small
Magellanic Cloud, allowing us to probe multiplicity in the
lowest-metallicity conditions to date (Z=0/2Z☉). BLOeM will
provide (i) the binary fraction, (ii) the orbital configurations of
systems with periods of P≲3yr, (iii) dormant black-hole binary
candidates (OB+BH), and (iv) a legacy database of physical parameters
of massive stars at low metallicity. Main sequence (OB-type) and
evolved (OBAF-type) massive stars are observed with the LR02 setup of
the giraffe instrument of the Very Large Telescope (3960-4570Å
resolving power R=6200; typical signal-to-noise ratio (S/N)∼70-100).
This paper utilises the first nine epochs obtained over a three-month
time period. We describe the survey and data reduction, perform a
spectral classification of the stacked spectra, and construct a
Hertzsprung-Russell diagram of the sample via spectral-type and
photometric calibrations. Our detailed classification reveals that the
sample covers spectral types from O4 to F5, spanning the effective
temperature and luminosity ranges 6:5≲Te/kK≲45 and
3.7<logL/L☉<6.1 and initial masses of 8≲Mini≲80M☉. The
sample comprises 159 O-type stars, 331 early B-type (B0-3) dwarfs and
giants (luminosity classes V-III), 303 early B-type supergiants
(II-I), and 136 late-type BAF supergiants. At least 82 stars are OBe
stars: 20 O-type and 62 B-type (13% and 11% of the respective
samples). In addition, the sample includes 4 high-mass X-ray binaries,
3 stars resembling luminous blue variables, 2 bloated stripped-star
candidates, 2 candidate magnetic stars, and 74 eclipsing binaries.
Description:
We present the Binarity at LOw Metallicity (BLOeM) campaign, an ESO
large programme designed to obtain 25 epochs of spectroscopy for 929
massive stars in the Small Magellanic Cloud.
Table A.2: Aliases, K-band magnitudes, spectral types,
and additional information for the 929 BLOeM targets
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea2.dat 192 929 Aliases, K-band magnitudes, spectral types, and
additional information for the 929 BLOeM targets
refs.dat 78 46 References
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- ID BLOeM identifier (N-NNN)
7- 25 I19 --- GaiaDR3 Gaia Data Release 3 identifier
27- 41 F15.11 deg RAdeg Gaia DR3 right ascension (ICRS)
at Ep=2016.0
43- 57 F15.11 deg DEdeg Gaia DR3 declination (ICRS) at Ep=2026.0
59- 92 A34 --- OName Common aliases in the literature
94- 98 F5.2 mag Ksmag ?=- K-band magnitude
100-125 A26 --- SpTypeold Literature spectral type (1)
127-154 A28 --- SpTypenew Spectral type from this study
156-158 A3 --- Halpha [yes no -] H-alpha emitters in
Gaia low-resolution spectra
160-192 A33 --- Comment Additional comments (1)
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Note (1): References in refs.dat file.
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Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ref Reference code
7- 25 A19 --- BibCode BibCode
27- 56 A30 --- Aut Author's name
58- 78 A21 --- Com Comments
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Acknowledgements:
Tomer Shenar, tshenar(at)tau.ac.il
(End) Patricia Vannier [CDS] 23-Sep-2024