J/AJ/156/45 M-dwarf multiples in the SDSS-III/APOGEE (Skinner+, 2018)
Forty-four new and known M-dwarf multiples in the SDSS-III/APOGEE M-dwarf
ancillary science sample.
Skinner J., Covey K.R., Bender C.F., Rivera N., De Lee N., Souto D.,
Chojnowski D., Troup N., Badenes C., Bizyaev D., Blake C.H., Burgasser A.,
Canas C., Carlberg J., Maqueo Chew Y.G., Deshpande R., Fleming S.W.,
Fernandez-Trincado J.G., Garcia-Hernandez D.A., Hearty F., Kounkel M.,
Longa-Pene P., Mahadevan S., Majewski S.R., Minniti D., Nidever D.,
Oravetz A., Pan K., Stassun K., Terrien R., Zamora O.
<Astron. J., 156, 45 (2018)>
=2018AJ....156...45S 2018AJ....156...45S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, dwarfs ; Stars, M-type ;
Stars, masses ; Radial velocities
Keywords: binaries: close - binaries: general - binaries: spectroscopic -
stars: formation - stars: low-mass
Abstract:
Binary stars make up a significant portion of all stellar systems.
Consequently, an understanding of the bulk properties of binary stars
is necessary for a full picture of star formation. Binary surveys
indicate that both multiplicity fraction and typical orbital separation
increase as functions of primary mass. Correlations with higher-order
architectural parameters such as mass ratio are less well constrained.
We seek to identify and characterize double-lined spectroscopic
binaries (SB2s) among the 1350 M-dwarf ancillary science targets with
APOGEE spectra in the SDSS-III Data Release 13. We measure the degree
of asymmetry in the APOGEE pipeline cross-correlation functions (CCFs)
and use those metrics to identify a sample of 44 high-likelihood
candidate SB2s. At least 11 of these SB2s are known, having been
previously identified by Deshpande et al. (2013, J/AJ/146/156) and/or
El-Badry et al. (2018MNRAS.476..528E 2018MNRAS.476..528E). We are able to extract radial
velocities (RVs) for the components of 36 of these systems from their
CCFs. With these RVs, we measure mass ratios for 29 SB2s and five SB3s.
We use Bayesian techniques to fit maximum-likelihood (but still
preliminary) orbits for four SB2s with eight or more distinct APOGEE
observations. The observed (but incomplete) mass-ratio distribution of
this sample rises quickly toward unity. Two-sided Kolmogorov-Smirnov
tests find probabilities of 18.3% and 18.7%, demonstrating that the
mass-ratio distribution of our sample is consistent with those measured
by Pourbaix et al. (2004, Cat. B/sb9) and Fernandez et al.
(2017PASP..129h4201F 2017PASP..129h4201F), respectively.
Description:
The SDSS-III (Eisenstein et al. 2011AJ....142...72E 2011AJ....142...72E) APOGEE M-dwarf
ancillary program (Deshpande et al. 2013, J/AJ/146/156; Holtzman et al.
2015AJ....150..148H 2015AJ....150..148H) was designed to produce a large, homogeneous spectral
library and kinematic catalog of nearby low-mass stars; these data products
are useful for investigations of stellar astrophysics (e.g., Souto et al.
2017ApJ...835..239S 2017ApJ...835..239S; Gilhool et al. 2018, J/AJ/155/38) and refining
targeting procedures for current and future exoplanet search programs.
These science goals are uniquely enabled by the APOGEE spectrograph
(Wilson et al. 2010SPIE.7735E..1CW, 2012SPIE.8446E..0HW), which acquires
high-resolution (R∼22000) near-infrared spectra from each of 300 optical
fibers. As deployed at the 2.5 m SDSS telescope (Gunn et al.
2006AJ....131.2332G 2006AJ....131.2332G), the APOGEE spectrograph achieves a field of view
with a diameter of 3°, making it a highly efficient instrument for
surveying the stellar parameters of the constituents of Galactic stellar
populations (Majewski et al. 2017AJ....154...94M 2017AJ....154...94M). The SDSS DR13 data
release (Albareti et al. 2017ApJS..233...25A 2017ApJS..233...25A) includes 7152 APOGEE spectra
of 1350 stars targeted by this ancillary program.
We used the TODCOR algorithm (Zucker & Mazeh 1994ApJ...420..806Z 1994ApJ...420..806Z) to
measure RVs from all HET/HRS spectra and any APOGEE spectra flagged
with low-RV separations. This TODCOR analysis followed the procedures
previously discussed by Bender et al. (2005AJ....129..402B 2005AJ....129..402B) and used the
algorithm implementation of Bender et al. (2012ApJ...751L..31B 2012ApJ...751L..31B).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 63 44 Selected binaries
table3.dat 91 184 Radial velocity measurements of SB2s
table4.dat 91 15 Radial velocity measurements of SB3s
table5.dat 45 34 Mass ratio and ΔRV of analyzed stars
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See also:
B/sb9 : SB9: 9th Catalogue of Spectroscopic Binary Orbits
(Pourbaix+ 2004-2014)
J/AJ/146/156 : APOGEE M-dwarf survey. I. First year velocities
(Deshpande+, 2013)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
J/MNRAS/449/2618 : M-dwarfs in Multiples (MinMs) survey. I. (Ward-Duong+, 2015)
J/AJ/155/38 : The rotation of M dwarfs observed by APOGEE (Gilhool+, 2018)
http://www.sdss3.org/ : The SDSS-III website
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- 2MASS 2MASS identifier (2MHHMMSSss+DDMMSSs)
20- 22 A3 --- f_2MASS Flag on 2MASS (1)
24- 28 F5.3 Msun Mass [0.109/0.926] Photometricly derived mass (2)
29 A1 --- f_Mass [*] Flag on Mass (3)
31- 32 I2 --- Nvis [3/15] Number of visits
34- 38 F5.2 --- R151 [2.46/10.64] R value for central 151 lags (4)
40- 43 F4.2 --- R101 [2.06/9.14] R value for central 101 lags (4)
45- 48 F4.2 --- R51 [2.12/6.7] R value for central 51 lags (4)
50- 53 F4.2 --- CCF [0.32/0.89] Maximum cross-correlation function
55- 60 F6.2 --- XRange [5.27/186.37] Bisector width (5)
62- 63 I2 --- Sep [0/12] Well separated epochs
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Note (1): Flag as follows:
1 = Identified by Deshpande et al. (2013, J/AJ/146/156) as an SB2;
2 = Identified by El-Badry et al. (2018MNRAS.473.5043E 2018MNRAS.473.5043E) as an SB2;
3 = Found here to be an SB3;
4 = Found here to be an SB4;
5 = Identified by El-Badry et al. (2018MNRAS.473.5043E 2018MNRAS.473.5043E) as an SB3.
Note (2): Estimated from the (V-K)-versus-mass relation derived by
Delfosse et al. (2000A&A...364..217D 2000A&A...364..217D).
Note (3): Flag as follows:
* = Mass determined from the MK-versus-mass relation derived by Mann et al.
(2015, J/ApJ/804/64), after adopting a distance based on a measured
trigonometric parallax or a fiducial solar neighborhood distance of 20 pc.
Note (4): Following Fernandez et al. 2017PASP..129h4201F 2017PASP..129h4201F, we characterized the
asymmetry in each cross-correlation function (CCF) using the R parameter
originally developed by Tonry & Davis (1979AJ.....84.1511T 1979AJ.....84.1511T):
R=H/sqrt(2σa), where H is the maximum of the CCF, and σa is
the rms of the antisymmetric portion of the CCF. In this formalism, lower R
values indicate sources with larger asymmetries in their CCF functions. To
better identify sources with CCF asymmetries at physically meaningful velocity
separations, we computed distinct R values for windows of differing widths
around each CCF's central peak. Specifically, we computed R values for the
central 51, 101, and 151 lags in each CCF, which we denote as R51, R101,
and R151, respectively.
Note (5): To provide additional measures of the structure of each CCF, we also
record the maximum response and bisector width of each CCF as peak and
bisectorX, respectively.
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Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- 2MASS 2MASS identifier (2MHHMMSSss+DDMMSSs)
20- 21 I2 --- Nvis [1/20] Number of visits
23 A1 --- f_Nvis Flag on Nvis (only in Table 3) (1)
25- 34 F10.4 d MJD [55811.11/56836.4321] Epoch
36- 49 A14 --- PMF SDSS Plate-MJD-Fiber
51- 53 I3 --- S/N [6/549] Signal-to-noise ratio
55- 61 F7.2 km/s RV1 [-183.3/109.2]? Primary radial velocity (2)
63- 66 F4.2 km/s e_RV1 [0.12/0.56]? Uncertainty in RV1 (2)
68- 74 F7.2 km/s RV2 [-186.3/116.2]? Secondary radial velocity (2)
76- 79 F4.2 km/s e_RV2 [0.12/2.5]? Uncertainty in RV2 (2)
81- 86 F6.2 km/s RV3 [-57.52/20.1]? Tertiary radial velocity
(only in Table 4) (2)
88- 91 F4.2 km/s e_RV3 [0.24/1.02]? Uncertainty in RV3 (only in Table 4)
(2)
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Note (1): Flag as follows:
* = These visits are from the Hobby-Eberly Telescope (HET) High-Resolution
Spectrograph (HRS). S/N is highly wavelength dependent for M-dwarfs;
values reported here are at 7500 nm. TODCOR was used for RV extraction;
1 = TODCOR used for RV extraction;
2 = Radial velocities for these epochs were mis-assigned by the extraction
routine described in Section 3.1, and manually corrected.
Note (2): In Table 3, RVs not extracted via TODCOR are assigned the ensemble
uncertainty of ∼1.8 km/s. All velocities in Table 4 were extracted via TODCOR.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- 2MASS 2MASS identifier (2MHHMMSSss+DDMMSSs)
20 A1 --- f_2MASS Flag on 2MASS (1)
22- 26 F5.3 --- q [0.217/0.998] Mass ratio; Msec/Mpri
28- 32 F5.3 --- e_q [0.001/0.389]? Uncertainty in q
34- 38 F5.3 --- Ratio [0.002/0.688]? Ratio of e_q to q
40- 45 F6.2 km/s MaxDelRV [29.56/161.26] Maximum primary-secondary
velocity separation MaxΔRV
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Note (1): Flag as follows:
1 = For these targets, q>1. We assume this is due to a primary/secondary
mismatch, and report q-1 as q;
2 = Only two epochs were usable for these targets, therefore e_q is not well
defined.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 22-Jan-2019