J/ApJ/877/60 YMGs. I. Young binaries & lithium-rich stars (Bowler+, 2019)
The elusive majority of young moving groups.
I. Young binaries and lithium-rich stars in the solar neighborhood.
Bowler B.P., Hinkley S., Ziegler C., Baranec C., Gizis J.E., Law N.M.,
Liu M.C., Shah V.S., Shkolnik E.L., Riaz B., Riddle R.
<Astrophys. J., 877, 60 (2019)>
=2019ApJ...877...60B 2019ApJ...877...60B
ADC_Keywords: Stars, nearby; Stars, double and multiple; Stars, late-type;
Spectra, optical; Equivalent widths; Spectral types; YSOs
Radial velocities; Infrared sources; Proper motions
Keywords: binaries: visual ; stars: low-mass
Abstract:
Young stars in the solar neighborhood serve as nearby probes of
stellar evolution and represent promising targets to directly image
self-luminous giant planets. We have carried out an all-sky search for
late-type (∼K7-M5) stars within 100pc selected primarily on the basis
of activity indicators from the Galaxy Evolution Explorer and ROSAT.
Approximately 2000 active and potentially young stars are identified,
of which we have followed up over 600 with low-resolution optical
spectroscopy and over 1000 with diffraction-limited imaging using
Robo-AO at the Palomar 1.5m telescope. Strong lithium is present in
58 stars, implying ages spanning ∼10-200Myr. Most of these
lithium-rich stars are new or previously known members of young moving
groups including TWA, βPic, Tuc-Hor, Carina, Columba, Argus,
ABDor, Upper Centaurus Lupus, and Lower Centaurus Crux; the rest
appear to be young low-mass stars without connections to established
kinematic groups. Over 200 close binaries are identified down to
0.2"-the vast majority of which are new-and will be valuable for
dynamical mass measurements of young stars with continued orbit
monitoring in the future.
Description:
To better characterize our starting sample of 2060 activity-selected
late-K and early-M dwarfs, we carried out a follow-up observational
program to obtain low-resolution optical spectra of these targets
using instruments in the northern and southern hemispheres, together
with AO imaging with Robo-AO at the Palomar 60in (1.5m) telescope in
the north. Altogether we acquired 762 optical spectra of 632 stars,
plus an additional four nearby stars sharing common proper motions
with targets in our sample. We also obtained 1523 AO images of 1011
stars to uncover and characterize close binaries.
Observations with the RC-Spectrograph mounted on the 4m Mayall
telescope at Kitt Peak were carried out over eight nights on UT 2013
December 29-31, UT 2014 May 21-23, and UT 2015 June 16-17; instrument
setup produced an average resolving power of R∼2600 spanning 6200-9200Å.
A total of 244 spectra were obtained for 168 stars with the Goodman
High-Throughput Spectrograph at the Southern Astrophysical Research
(SOAR) 4.1m telescope located on Cerro Pachon, Chile. The observations
spanned nine nights on three observing runs: UT 2013 December 4-7, UT
2014 June 25-28, and UT 2015 February 16.
We acquired low-resolution (R∼1300) optical spectra for 40 stars on UT
2014 January 19 and 21 with the SuperNova Integral Field Spectrograph
(SNIFS) at the University of Hawai'i's 88 in (2.2m) telescope located
on Maunakea, Hawai'i.
Our spectroscopic observations are detailed in Table 1.
The 1523 adaptive optics images of 1011 targets from our parent sample
of 2060 active stars were obtained with Robo-AO at the Palomar 60in
(1.5m) telescope between 2013 July and 2015 June. See Section 3.4;
details about our individual observations can be found in Table 2.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 97 762 Spectroscopic observations for 634 targets
table2.dat 45 1523 Robo-AO observations for 1011 targets
table3.dat 161 58 Properties of lithium-rich stars
table4.dat 74 461 Robo-AO point source detections
table5.dat 99 252 Binary common proper motion tests
table6.dat 152 238 Properties of Robo-AO for the 238 visual binaries
refs.dat 164 72 References
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2020)
II/179 : Southern Spectrophotometric Standards. I + II (Hamuy+ 1992,94)
III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)
I/282 : The CMT CCD Drift Scan Survey (Evans+, 2002)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/106/1059 : Lithium in the Pleiades (Soderblom+, 1993)
J/A+AS/132/173 : New weak-line T Tauri stars in Taurus-Auriga (Li+ 1998)
J/PASP/110/1012 : New double stars from HST (Schneider+, 1998)
J/A+A/356/541 : T Tauri stars in Sco-Cen OB association (Koehler+, 2000)
J/AJ/132/866 : New M dwarfs in solar neighborhood (Riaz+, 2006)
J/AJ/132/2665 : QUEST2 BRI photom. of Taurus-Auriga PMS (Slesnick+, 2006)
J/A+A/460/695 : Search for Assoc. Containing Young stars (Torres+, 2006)
J/AJ/134/2398 : Stellar SEDs in SDSS and 2MASS filters (Covey+, 2007)
J/AJ/134/741 : New close binary syst. from SDSS DR5 (Silvestri+, 2007)
J/ApJS/172/663 : Infrared observations of the Pleiades (Stauffer+, 2007)
J/AJ/133/2524 : Spectra of young nearby stars (White+, 2007)
J/A+A/508/833 : SACY III. Li abundances (da Silva+, 2009)
J/ApJS/184/138 : XID II: RASS/BSC-2MASS/PSC cross-assoc. (Haakonsen+, 2009)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/AJ/140/119 : βPic & ABDor moving groups members (Schlieder+, 2010)
J/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011)
J/A+A/531/A92 : Deep all-sky census of the Hyades (Roeser+, 2011)
J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)
J/ApJ/754/44 : The AstraLux Large M-dwarf Survey (Janson+ 2012)
J/ApJ/745/119 : Close companions to young stars. I. (Nguyen+, 2012)
J/AJ/143/80 : Low-mass members of βPic & ABDOR (Schlieder+, 2012)
J/ApJ/758/56 : Young M dwarfs within 25pc. II. (Shkolnik+, 2012)
J/AJ/144/8 : G/K/M-type Sco-Cen complex member spectroscopy (Song+, 2012)
J/ApJ/777/160 : NIR survey for planets around MG stars (Biller+, 2013)
J/MNRAS/435/2161 : Catalogue of bright (K<9) M dwarfs (Frith+, 2013)
J/MNRAS/429/859 : New companions to nearby low-mass stars (Jodar+, 2013)
J/A+A/551/A46 : Compiled photom. for ChamI & II members (Lopez Marti+, 2013)
J/ApJ/762/88 : Young stellar kinematic group cand. members (Malo+, 2013)
J/MNRAS/435/1325 : Membership of the ε Cha assoc. (Murphy+, 2013)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/A+A/568/A26 : SACY. V. Multiple systems (Elliott+, 2014)
J/ApJ/783/121 : BANYAN II. Nearby young assoc. cand. members (Gagne+, 2014)
J/MNRAS/443/2561 : CONCH-SHELL catalog of nearby M dwarfs (Gaidos+, 2014)
J/ApJ/789/102 : Properties of late M-dwarfs (Janson+, 2014)
J/ApJS/214/17 : Orbital monitoring of AstraLux binaries (Janson+, 2014)
J/AJ/147/146 : Spectroscopy of Tuc-Hor candidate members (Kraus+, 2014)
J/ApJ/791/35 : Detection of 715 Kepler planet cand. host stars (Law+, 2014)
J/ApJ/788/81 : BANYAN III. RV & rotation of low-mass stars (Malo+, 2014)
J/AJ/147/85 : Solar neighborhood. XXXIII. 45 M dwarfs (Riedel+, 2014)
J/AJ/148/64 : HAZMAT. I. FUV & NUV emission in M stars (Shkolnik+, 2014)
J/ApJ/798/41 : GALEX NUV obs. of bright M-type stars (Ansdell+, 2015)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/MNRAS/452/173 : Nearby young stars in Northern hemisphere (Binks+, 2015)
J/ApJS/216/7 : Planets Around Low-Mass Stars (PALMS). IV. (Bowler+, 2015)
J/A+A/573/A126 : VLT/NaCo Large program I. Sample (Desidera+, 2015)
J/A+A/580/A88 : Stellar multiplicity in 3-1000AU (Elliott+, 2015)
J/ApJS/219/33 : BANYAN. VII. Cand. YMG members from BASS (Gagne+, 2015)
J/MNRAS/453/2220 : Early-type Sco-Cen members with lit. RVs (Murphy+, 2015)
J/ApJ/827/142 : ALMA obs. of GKM stars in Upper Sco (Barenfeld+, 2016)
J/A+A/590/A13 : New cand. members in young associations (Elliott+, 2016)
J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)
J/MNRAS/461/794 : Scorpius-Centaurus K-Type Stars (Pecaut+, 2016)
J/A+A/599/A70 : Young moving group M-dwarf multiplicity (Janson+, 2017)
J/ApJ/838/150 : The Taurus-Auriga ecosystem. I. (Kraus+, 2017)
J/AJ/154/129 : PSYM-WIDE: YMG stars planetary-mass companions (Naud+, 2017)
J/ApJ/840/87 : Young star systems observed with SALT (Riedel+, 2017)
J/ApJ/846/93 : Mult. of M dwarfs in young moving groups (Shan+, 2017)
J/AJ/154/69 : ACRONYM II. β Pictoris Moving Group (Shkolnik+, 2017)
J/AJ/153/66 : Robo-AO Kepler Planetary Cand. Survey. III. (Ziegler+, 2017)
J/A+A/618/A5 : RV survey of low-mass binaries (Durkan+, 2018)
J/ApJ/862/138 : BANYAN. XIII. Gaia DR2 nearby young assoc. (Gagne+, 2018)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/ApJ/868/32 : A large moving group within the LCC assoc. (Goldman+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identifier
18- 21 A4 --- m_2MASS 2MASS component ("(E)", "(W)" or "(SW)")
23- 25 A3 --- f_2MASS Flag on 2MASS (1)
27- 30 I4 yr Obs.Y [2013/2015] UT Year of the observation
32- 33 I2 "month" Obs.M UT Month of the observation
35- 36 I2 d Obs.D UT Day of the observation
38- 51 A14 --- Tel The Telescope/Instrument used
53- 60 A8 --- Grating Grating used
62- 65 I4 --- Res [1300/5900] Resolving power
67- 69 I3 s Exp [20/600] Exposure time
71- 75 F5.1 0.1nm EWHa [-62.6/4.4]? Hα equivalent width (2)
77- 80 F4.2 0.1nm EWLi [0.06/0.6]? Li I (6708A) equivalent width (2)
82- 84 F3.1 0.1nm EWNa [0.4/6.8]? Na I (8200A) equivalent width (2)
86- 89 F4.2 --- TiO5 [0.27/1.05] The TiO5 index
91- 92 A2 --- H-SpT The Hammer derived spectral type (3)
94- 97 A4 --- V-SpT Visual inspection spectral type (3)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
c = Likely SB2.
d = Visual binary.
e = Common proper motion companion to a star in the parent sample.
Note (2): Negative values indicate emission. Uncertainties are estimated
to be 10% of the quoted values.
Note (3): Spectral types from Hammer have been shown to have a systematic
offset of about one spectral subclass for cool stars. Uncertainties
are ±1 subclass. Our visual spectral types are more robust and
have uncertainties of ±0.5 subclasses.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identifier
19- 22 I4 yr Obs.Y [2013/2015] UT Year of the observation
24- 25 I2 "month" Obs.M UT Month of the observation
27- 28 I2 d Obs.D UT Day of the observation
30- 36 A7 --- Filter Filter used
38- 40 I3 s Exp [30/120] Exposure time
42- 45 F4.2 arcsec FWHM [0/0.86] Measured Full-Width at Half-Maximum
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identifier
19- 22 A4 --- SpT Spectral type
24- 27 A4 --- r_SpT Reference for SpType (see refs.dat file)
29- 34 F6.2 km/s RV [-22.0/21.2]? Radial velocity
36- 39 F4.2 km/s e_RV [0.1/8.0]? Uncertainty in RV
41- 45 A5 --- r_RV Reference for RV (see refs.dat file)
47- 52 F6.2 mas/yr pmRA [-78.8/88.7] Proper motion along RA
times cos(DE) (1)
54- 57 F4.2 mas/yr e_pmRA [0.03/2] Uncertainty in pmRA (1)
58 A1 --- f_pmRA [b] b: Proper motion from UCAC4 (I/322)
60- 66 F7.2 mas/yr pmDE [-105.4/32.4] Proper motion along DE (1)
68- 71 F4.2 mas/yr e_pmDE [0.03/2.3] Uncertainty in pmDE (1)
72 A1 --- f_pmDE [b] b: Proper motion from UCAC4 (I/322)
74- 79 F6.2 pc Dist [44.5/450]? Distance (1)
81- 86 F6.2 pc e_Dist [0.05/161]? Uncertainty in Dist (1)
87 A1 --- f_Dist [c] Flag on Dist (2)
89-101 A13 --- Best The BANYAN Σ Best Hypotheses
103-118 A16 --- Lit Literature YMG
120-136 A17 --- Adopt Adopted YMG
138-161 A24 --- r_Lit Reference for Lit (see refs.dat file)
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Note (1): From Gaia DR2, unless otherwise noted.
Note (2): Flag as follows:
c = Large excess noise parameter in Gaia DR2, implying the astrometric
solution may not be reliable.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identifier
19- 22 I4 yr Obs.Y [2013/2015] UT Year of the observation
24- 25 I2 "month" Obs.M UT Month of the observation
27- 28 I2 d Obs.D UT Day of the observation
30- 34 A5 --- Filt Filter used ("LP600" or "i'")
36- 38 A3 --- CCand Candidate Name (CC1, CC2 or CC3)
40- 44 F5.2 mag Delmag [-0.1/8.2]? Optical contrast in Filter
46- 49 F4.2 mag e_Delmag [0.02/0.6]? Uncertainty in Delmag
51- 54 F4.2 arcsec Sep [0.17/4.2] Separation
56- 59 F4.2 arcsec e_Sep [0.01/0.07] Uncertainty in Sep
61- 63 I3 deg PA [0/359] Position angle
65 I1 deg e_PA [1/6] Uncertainty in PA
67- 72 F6.1 --- sigma [3.6/2386.5] Significance
74- 74 A1 --- Perf Performance Metric (1)
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Note (1): Image performance metrics assessed from the PSF core size. These
are divided into three groups as follows:
H = high-performance,
M = medium-performance, and
L = low-performance.
Typical contrasts for each group are described in detail in Section 3.4.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identifier
19 I1 --- Nep [1/8] Number of epochs
21- 27 F7.5 yr Delta [0.0028/1.61]? Time between epochs
29- 31 A3 --- CCand Candidate companion (CC1, CC2 or CC3)
33- 41 F9.4 --- BG-chi2 [0.09/8500]? Reduced chi squared value of
background hypotheses
43- 49 F7.4 --- CPM-chi2 [0/49.5]? Reduced chi squared value of common
proper motion hypotheses
51 I1 --- nu [0/7] Degrees of freedom
53- 60 F8.2 --- BG-BIC [3.5/17000]? Bayesian Information Criterion
of background hypotheses
62- 67 F6.2 --- CPM-BIC [3.4/206]? Bayesian Information Criterion
of common proper motion hypotheses
69- 79 F11.5 --- DelBIC [-196/17000]? Differenced BIC value
81- 84 A4 --- Comp? Companion? (1)
86 A1 --- Bin? [YN] Known Binary?
88- 99 A12 --- r_Bin? Binary reference (see refs.dat file)
--------------------------------------------------------------------------------
Note (1): Status of companion based on differenced Bayesian Information
Criterion for the common proper motion and background hypotheses.
SE = Single Epoch;
BG = background;
CPM = Common Proper Motion. See Section 4.2 for details.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identifier
19- 25 F7.2 mas/yr pmRA [-589/614.4] Proper motion
along RA times cos(DE) (1)
27- 31 F5.2 mas/yr e_pmRA [0.03/10.2] Uncertainty in pmRAcosDE (1)
32 A1 --- f_pmRA [b] b: Proper motion from UCAC4 (I/322)
34- 40 F7.2 mas/yr pmDE [-386.2/352] Proper motion along DE (1)
42- 45 F4.2 mas/yr e_pmDE [0.03/9.3] Uncertainty in pmDE (1)
46 A1 --- f_pmDE [b] b: Proper motion from UCAC4 (I/322)
48- 53 F6.2 pc Dist [11.7/450.3]? Distance (1)
55- 60 F6.2 pc e_Dist [0.01/161.1]? Uncertainty in Dist (1)
62- 64 A3 --- Cand1 [CC1] First Candidate Companion
66- 68 A3 --- Cand2 [CC2] Second Candidate Companion
70- 72 A3 --- Cand3 [CC3] Third Candidate Companion
74- 77 F4.2 arcsec Sep1 [0.17/4.2] Projected separation with Cand1
79- 82 F4.2 arcsec Sep2 [0.7/3.8]? Projected separation with Cand2
84- 87 F4.2 arcsec Sep3 [0.49]? Projected separation with Cand3
89- 98 A10 --- Best BANYAN Σ Best Hyptheses
100-123 A24 --- Lit Literature YMG
125-152 A28 --- r_Lit Reference for Lit (see refs.dat)
--------------------------------------------------------------------------------
Note (1): Proper motions and parallactic distance from Gaia DR2, unless
otherwise noted.
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Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Ref Reference code
8- 26 A19 --- BibCode Bibcode of the reference
28- 52 A25 --- Auth First author's name(s)
54-164 A111 --- Comm Comment
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-Nov-2020