J/A+A/618/A5 Radial velocity survey of low-mass binaries (Durkan+, 2018)
Radial velocity survey of spatially resolved young, low-mass binaries.
Durkan S., Janson M., Ciceri S., Brandner W., Schlieder J.,
Henning T., Bonnefoy M., Kankare J., Watson C.A.
<Astron. Astrophys. 618, A5 (2018)>
=2018A&A...618A...5D 2018A&A...618A...5D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, late-type ;
Stars, pre-main sequence ; Radial velocities
Keywords: binaries: spectroscopic - binaries: visual - stars: pre-main sequence
Abstract:
The identification and characterisation of low-mass binaries is of
importance for a range of astrophysical investigations. Low-mass
binaries in young (∼10-100Myr) moving groups (YMGs) in the solar
neighborhood are of particular significance as they provide unique
opportunities to calibrate stellar models and evaluate the ages and
coevality of the groups themselves. Low-mass M-dwarfs have pre-main
sequence life times on the order of ∼100Myr and therefore are
continually evolving along a mass-luminosity track throughout the YMG
phase, providing ideal laboratories for precise isochronal dating, if
a model-independent dynamical mass can be measured. AstraLux lucky
imaging multiplicity surveys have recently identified hundreds of new
YMG low-mass binaries, where a subsample of M-dwarf multiples have
estimated orbital periods less than 50 years. We have conducted a
radial velocity survey of a sample of 29 such targets to complement
the astrometric data. This will allow enhanced orbital determinations
and precise dynamical masses to be derived in a shorter timeframe than
possible with astrometric monitoring alone, and allow for a more
reliable isochronal analysis. Here we present radial velocity
measurements derived for our sample over several epochs.
We report the detection of the three-component spectroscopic multiple
2MASS J05301858-5358483, for which the C component is a new discovery,
and forms a tight pair with the B component. Originally identified as
a YMG member, we find that this system is a likely old field
interloper, whose high chromospheric activity level is caused by tidal
spin-up of the tight BC pair. Two other triple systems with a tight
pair exist in the sample, 2MASS J04244260-0647313 (previously known)
and 2MASS J20163382-0711456, but for the rest of the targets we find
that additional tidally synchronized companions are highly unlikely,
providing further evidence that their high chromospheric activity
levels are generally signatures of youth.
Description:
Table presenting the radial velocity measurements for the sample of
stellar multiples observed in the survey.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
stars.dat 47 29 List of studied stars
table2.dat 64 119 Radial velocity measurements
--------------------------------------------------------------------------------
See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: stars.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSss)
25- 26 I2 h RAh Rigth ascension (J2000)
28- 29 I2 min RAm Rigth ascension (J2000)
31- 35 F5.2 s RAs Rigth ascension (J2000)
37 A1 --- DE- Declination sign (J2000)
38- 39 I2 deg DEd Declination (J2000)
41- 42 I2 arcmin DEm Declination (J2000)
44- 47 F4.1 arcsec DEs Declination (J2000)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSSs)
19- 27 F9.3 d Epoch Epoch (MJD)
29- 34 F6.2 km/s RV Radial velocity
36- 39 F4.2 km/s e_RV Error on radial velocity
40 A1 --- n_RV [*] Note on RV (1)
41 A1 --- l_fc Limit flag on fc
42- 46 F5.3 --- fc ? Synchronizer detectability (see Sect 4.3)
48- 64 A17 --- Notes Target notes (2)
--------------------------------------------------------------------------------
Note (1): For SB3 system J04244260-0647313 we note the RV measured for the
central CCF peak, and peaks toward the blue and red with respect to the
central peak, as individual components cannot be distinguished between epochs.
For SB3 system J05301858-5358483 we note the RVs measured for the
identified ABC components, see Sect 4.1 for details.
Note (2): SB1 and SB3 denote a singled-lined binary and a three-component
spectroscopic multiple respectively.
--------------------------------------------------------------------------------
Acknowledgements:
Stephen Durkan, sdurkan01(at)qub.ac.uk
(End) Stephen Durkan [QUB, UK], Patricia Vannier [CDS] 22-Jun-2018