J/ApJ/875/124 Binary red supergiants. II. B-type companions (Neugent+, 2019)
Binary red supergiants.
II. Discovering and characterizing B-type companions.
Neugent K.F., Levesque E.M., Massey P., Morrell N.I.
<Astrophys. J., 875, 124-124 (2019)>
=2019ApJ...875..124N 2019ApJ...875..124N (SIMBAD/NED BibCode)
ADC_Keywords: Stars, supergiant; Stars, double and multiple; Stars, B-type;
Photometry, UBVRI; Spectra, optical; Effective temperatures
Keywords: binaries: close; binaries: spectroscopic; Galaxy: stellar content
stars: massive
Abstract:
The percentage of massive main-sequence OB stars in binary systems is
thought to be as high as 100%. However, very few Galactic binary red
supergiants (RSGs) have been identified, despite the fact that these
stars are the evolved descendants of OB stars. As shown in our recent
paper, binary RSGs will likely have B-type companions, as dictated by
stellar evolution considerations. Such a system will have a very
unique photometric signature due to the shape of the spectral energy
distribution. Using photometric cutoffs, it should therefore be
possible to detect candidate RSG+B star binary systems. Here we
present our spectroscopic follow-up observations of such candidates.
Out of our initial list of 280 candidates in M31 and M33, we observed
149 and confirmed 63 as newly discovered RSG+B star binary systems.
Additional spectra of four candidate systems in the Small Magellanic
Cloud confirmed all of them as new RSG+B star binaries including the
first known RSG+Be star system. By fitting BSTAR06 and MARCS model
atmospheres to the newly obtained spectra, we place estimates on the
temperatures and subtypes of both the B stars and RSGs. Overall, we
have found 87 new RSG+B star binary systems in M31, M33 and the Small
and Large Magellanic Clouds. Our future studies are aimed at
determining the binary fraction of RSGs.
Description:
We observe a sample of M31 and M33 red supergiant (RSG)+B star binary
candidates with the multi-object fiber-fed spectrograph, Hectospec, on
the 6.5m MMT. The M31 field was observed on UT 2018 September 14 while
the M33 field was observed on UT 2018 October 6 with a spectral
coverage from 3700 to 9000Å. See Section 2.
In addition to our M31 and M33 observations, we obtained spectra of
four RSG+B star binary candidates in the SMC using the 6.5m Magellan
Echellette (MagE) on the Baade Magellan telescope at Las Campanas.
See Section 3.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 89 125 Coordinates and magnitudes of classified M31
and M33 stars
table3.dat 62 24 Coordinates and magnitudes of confirmed SMC and
LMC RSG+B star binaries
table4.dat 34 87 Modeled physical parameters of confirmed RSG+B
star binaries
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See also:
III/23 : MK Classification for OB Stars (Lesh 1968)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/118/2211 : M31F eclipsing binaries and Cepheids (Mochejska+ 1999)
J/A+A/383/188 : Spectrophotometric atlas of symbiotic stars (Munari+, 2002)
J/AJ/123/855 : Magellanic Clouds Photometric Survey: SMC (Zaritsky+, 2002)
J/AJ/128/1606 : Magellanic Clouds Photometric Survey: LMC (Zaritsky+, 2004)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/ApJ/689/461 : Circumstellar disk of χ Oph (Tycner+, 2008)
J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)
J/AJ/140/14 : Variability of luminous stars in LMC (Szczygiel+, 2010)
J/A+A/532/A138 : V838 Mon spectrum in 2009 (Tylenda+, 2011)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
J/A+A/550/A107 : RV catalogue of O stars in 30 Doradus (Sana+, 2013)
J/ApJ/789/10 : M33 WR and Of-type Stars (Neugent+, 2014)
J/ApJ/900/118 : RSGs in the LMC & sp. follow-up for LMC & SMC (Neugent+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- LGGS LGGS identifier (JHHMMSS.ss+DDMMSS.s)
21- 22 I2 h RAh Hour of right ascension (J2000)
24- 25 I2 min RAm Minute of right ascension (J2000)
27- 31 F5.2 s RAs Second of right ascension (J2000)
33 A1 --- DE- Sign of declination (J2000)
34- 35 I2 deg DEd Degree of declination (J2000)
37- 38 I2 arcmin DEm Arcminute of declination (J2000)
40- 43 F4.1 arcsec DEs Arcsecond of declination (J2000)
45- 50 F6.3 mag Vmag [17.66/20] Johnson V magnitude (1)
52- 56 F5.3 mag B-V [0.1/2.2] Johnson B-V color index (1)
58- 63 F6.3 mag U-B [-1.05/0.72] Johnson U-B color index (1)
65- 69 F5.3 mag R-I [0.4/1.42] Kron-Cousins R-I color index (1)
71- 89 A19 --- Class Object class (2)
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Note (1): All photometry from Massey+ 2006, J/AJ/131/2478
Note (2): Class as follows:
A-type star = 13 occurrences
B-type star = 28 occurrences
RSG = 16 occurrences
RSG+B binary = 66 occurrences
RSG+HII = 1 occurrences
high-mass symbiotic = 1 occurrences
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 20 I2 h RAh Hour of right ascension (J2000)
22- 23 I2 min RAm Minute of right ascension (J2000)
25- 29 F5.2 s RAs Second of right ascension (J2000)
31 A1 --- DE- Sign of declination (J2000)
32- 33 I2 deg DEd Degree of declination (J2000)
35- 36 I2 arcmin DEm Arcminute of declination (J2000)
38- 41 F4.1 arcsec DEs Arcsecond of declination (J2000)
43- 48 F6.3 mag Vmag [12/14.7] Johnson V magnitude (1)
50- 55 F6.3 mag U-B [-0.72/1.9] Johnson U-B color index (1)
57- 62 F6.3 mag V-B [-1.76/-0.43] Johnson V-B color index (1)
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Note (1): SMC photometry from Zaritsky+ 2002, J/AJ/123/855 and LMC photometry
from Zaritsky+ 2004, J/AJ/128/1606
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- ID Identifier (JHHMMSS.ss+DDMMSS.s for LGGS or
JHHMMSSss+DDMMSSs for 2MASS)
21- 25 I5 K TeffB [15000/30000] B-star effective temperature
27 A1 --- Lcl B-star luminosity class
29 A1 --- f_Lcl [ab] Flag on Lcl (1)
31- 34 I4 K TeffRSG [3400/4250] RSG effective temperature
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Note (1): Flag as follows:
a = U-band luminosity suggests V.
b = U-band luminosity suggests I.
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History:
From electronic version of the journal
References:
Neugent et al. Paper I. 2018AJ....156..225N 2018AJ....156..225N
(End) Emmanuelle Perret [CDS] 30-Dec-2021