J/AJ/157/234 ACRONYM. III. Candidate young low-mass stars (Schneider+, 2019)
ACRONYM. III. Radial velocities for 336 candidate young low-mass stars in
the solar neighborhood, including 77 newly confirmed young moving group members.
Schneider A.C., Shkolnik E.L., Allers K.N., Kraus A.L., Liu M.C.,
Weinberger A.J., Flagg L.
<Astron. J., 157, 234 (2019)>
=2019AJ....157..234S 2019AJ....157..234S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, double and multiple ; Radial velocities ;
Spectral types ; Stars, distances ; Proper motions ; Photometry ;
Equivalent widths ; Parallaxes, trigonometric
Keywords: stars: low-mass
Abstract:
Young, low-mass stars in the solar neighborhood are vital for completing
the mass function for nearby, young coeval groups, establishing a more
complete census for evolutionary studies, and providing targets for
direct-imaging exoplanet and/or disk studies. We present properties derived
from high-resolution optical spectra for 336 candidate young nearby,
low-mass stars. These include measurements of radial velocities and age
diagnostics such as Hα and Li λ6707 equivalent widths.
Combining our radial velocities with astrometry from Gaia DR2 (Cat. I/345),
we provide full 3D kinematics for the entire sample. We combine the
measured spectroscopic youth information with additional age diagnostics
(e.g., X-ray and UV fluxes, color-magnitude diagram positions) and
kinematics to evaluate potential membership in nearby, young moving groups
and associations. We identify 77 objects in our sample as bona fide members
of 10 different moving groups, 14 of which are completely new members or
have had their group membership reassigned. We also reject 44 previously
proposed candidate moving group members. Furthermore, we have newly
identified or confirmed the youth of numerous additional stars that do not
belong to any currently known group and find 69 comoving systems using
Gaia DR2 astrometry. We also find evidence that the Carina association is
younger than previously thought, with an age similar to the β Pictoris
moving group (∼22 Myr).
Description:
Nearby young candidates were observed with the goal of identifying young,
nearby, low-mass stars. High-resolution optical spectra were acquired
for all targets to measure radial velocities and youth diagnostics.
Fifty-two targets were observed with HIRES (Vogt et al.
1994SPIE.2198..362V 1994SPIE.2198..362V) on the Keck I telescope. All observations were
taken with the 0.861" slit, resulting in a spectral resolution of
λ/Δλ∼58000 covering a wavelength range of
4900-9300 Å. The GG475 filter was utilized with the red cross-disperser
in order to maximize the throughput at the longest wavelengths. We observed
15 targets with ESPaDOnS (Donati et al. 2006ASPC..358..362D 2006ASPC..358..362D) on the CFHT.
ESPaDOnS covers a wavelength range of 3700-10400 Å, with a spectral
resolution of λ/Δλ∼68000. The MIKE optical spectrograph
located on the Clay telescope at the Magellan Observatory was used to
characterize 122 of our targets. We used the 0.5" slit for all MIKE
observations, which gives a spectral resolution of
λ/Δλ∼35000 over the wavelength range 4900-10000 Å.
Two-hundred and twenty-nine targets were observed with the Echelle
Spectrograph on the 2.5 m Irenee Du Pont Telescope. All observations
were taken with a 1.0" slit, resulting in a resolution of
λ/Δλ∼32000 covering the 4000-9000 Å wavelength
range.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 342 336 Sample properties
table1.dat 92 376 Observations summary
table3.dat 48 540 RV comparisons
table4.dat 96 145 Comoving systems
table6.dat 145 77 New and confirmed moving group members
table7.dat 145 44 Rejected moving group members
table8.dat 145 10 Low-probability candidate members
refs.dat 55 65 List of references
--------------------------------------------------------------------------------
See also:
IX/15 : Einstein EMSS Survey (Gioia+ 1990, Stocke+ 1991)
III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
I/340 : UCAC5 Catalogue (Zacharias+ 2017)
I/343 : Gaia-PS1-SDSS (GPS1) proper motion catalog (Tian+, 2017)
III/279 : RAVE 5th data release (Kunder+, 2017)
I/344 : The URAT Parallax Catalog (UPC). Update 2018 (Finch+, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
J/A+AS/115/41 : UBV(RI) photometry of cool stars (Cutispoto+, 1996)
J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)
J/AJ/126/3007 : Spectroscopy of faint red NLTT dwarfs (Reid+, 2003)
J/AJ/128/463 : A preliminary 20pc census from the NLTT catalogue
(Reid+, 2004)
J/ApJS/150/455 : New HIP-based parallaxes for 424 faint stars (Gould+, 2004)
J/A+A/460/695 : Search for Associations Containing Young stars
(Torres+, 2006)
J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006)
J/AJ/132/866 : New M dwarfs in solar neighborhood (Riaz+, 2006)
J/MNRAS/373/705 : Optical spectroscopy of high proper motion stars
(Reyle+, 2006)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/ApJ/689/1295 : Lithium test implications for brown dwarfs
(Kirkpatrick+, 2008)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/AJ/140/119 : βPic and AB Dor moving groups members
(Schlieder+, 2010)
J/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011)
J/ApJ/754/44 : The AstraLux Large M-dwarf Survey (Janson+ 2012)
J/ApJ/762/88 : Young stellar kinematic group candidate members
(Malo+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars
(Pecaut+, 2013)
J/MNRAS/435/1325 : Membership of the ε Cha association (Murphy+, 2013)
J/AJ/147/20 : Spectroscopy of 447 nearby M dwarfs (Newton+, 2014)
J/AJ/147/85 : Solar neighborhood. XXXIII. 45 M dwarfs (Riedel+, 2014)
J/AJ/147/146 : Spectroscopy of Tuc-Hor candidate members (Kraus+, 2014)
J/AJ/148/119 : UCAC4 nearby star survey (Finch+, 2014)
J/ApJ/784/156 : Parallaxes for 1507 nearby mid-to-late M dwarfs
(Dittmann+, 2014)
J/ApJ/788/81 : BANYAN III. RVel and rotation of low-mass stars
(Malo+, 2014)
J/MNRAS/443/2561 : CONCH-SHELL catalog of nearby M dwarfs (Gaidos+, 2014)
J/ApJ/798/73 : BANYAN All-Sky Survey (BASS) catalog. V. Nearby YMGs
(Gagne+, 2015)
J/ApJS/219/33 : BANYAN. VII. Candidate YMG members from BASS (Gagne+, 2015)
J/MNRAS/452/173 : Nearby young stars in Northern hemisphere (Binks+, 2015)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/A+A/592/A126 : Transition disk survey (van der Marel+, 2016)
J/AJ/151/160 : 1103 parallaxes and proper motions from URAT (Finch+, 2016)
J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)
J/MNRAS/457/2192 : NCJM catalog of M dwarfs (Cook+, 2016)
J/AJ/153/14 : Solar neighborhood XXXVIII. Nearby M dwarf systems
(Winters+, 2017)
J/AJ/154/69 : ACRONYM II. The β Pictoris Moving Group
(Shkolnik+, 2017)
J/AJ/154/151 : The solar neighborhood .XXXX. New young stars
(Bartlett+, 2017)
J/ApJ/846/93 : The multiplicity of M dwarfs in young moving groups
(Shan+, 2017)
J/A+A/612/A96 : Spectroscopic survey of youngest field stars II.
(Frasca+, 2018)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/ApJ/860/43 : BANYAN. XII. New members from Gaia-Tycho data (Gagne+, 2018)
J/ApJS/234/1 : Catalog of M, L, + T dwarfs from PS1 3π Survey
(Best+, 2018)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs)
18- 22 A5 --- SpType Spectral type
24- 25 I2 --- n_SpType [1/32] Reference for SpType (1)
27- 34 F8.3 pc Dist [4.55/2651.113]? Gaia DR2 (Cat. I/347) distance
36- 42 F7.3 pc e_Dist [0.001/278.325]? Uncertainty in Dist
44 A1 --- n_Dist Reference for Dist (2)
46- 53 F8.3 mas pmRA [-636.175/1691.123] Proper motion in RA
µα*cosδ
55- 59 F5.3 mas e_pmRA [0.026/6.9] Uncertainty in pmRA
61- 69 F9.3 mas pmDE [-1881.064/825.773] Proper motion in DE
µδ
71- 75 F5.3 mas e_pmDE [0.026/7.7] Uncertainty in pmDE
77 A1 --- n_pm Reference for pm (3)
79- 85 F7.2 km/s RV [-292.78/115.97] Radial velocity
87- 91 F5.2 km/s e_RV [0.08/67.57] Uncertainty in RV
93-100 F8.3 pc X [-454.652/1469.394]? X coordinate
102-107 F6.3 pc e_X [0.0/93.545]? Uncertainty in X
109-117 F9.3 pc Y [-2319.397/186.301]? Y coordinate
119-125 F7.3 pc e_Y [0/243.5]? Uncertainty in Y
127-134 F8.3 pc Z [-419.993/1251.985]? Z coordinate
136-142 F7.3 pc e_Z [0/131.439]? Uncertainty in Z
144-151 F8.3 km/s U [-284.971/62.655]? Velocity towards Galactic
center
153-158 F6.3 km/s e_U [0.016/45.941]? Uncertainty in U
160-167 F8.3 km/s V [-367.926/42.114]? Velocity in direction
of Galactic rotation
169-174 F6.3 km/s e_V [0.019/48.158]? Uncertainty in V
176-183 F8.3 km/s W [-113.926/42.299]? Velocity toward North
Galactic Pole
185-190 F6.3 km/s e_W [0.008/15.208]? Uncertainty in W
192-198 F7.4 mag Gmag [6.1774/19.0893]? Gaia G band magnitude
200-205 F6.4 mag e_Gmag [0.0002/0.0351]? Uncertainty in Gmag
207-213 F7.4 mag RPmag [5.6835/17.3748]? Gaia Red passband magnitude
215-220 F6.4 mag e_RPmag [0.0006/0.0507]? Uncertainty in RPmag
222-228 F7.4 mag BPmag [6.5608/20.7849]? Gaia Blue passband magnitude
230-235 F6.4 mag e_BPmag [0.0011/0.2457]? Uncertainty in BPmag
237-242 F6.3 mag Jmag [5.129/14.242] 2MASS J band magnitude
244-248 F5.3 mag e_Jmag [0.017/0.054] Uncertainty in Jmag
250-255 F6.3 mag Hmag [4.831/14.006] 2MASS H band magnitude
257-261 F5.3 mag e_Hmag [0.015/0.086] Uncertainty in Hmag
263-268 F6.3 mag Ksmag [4.529/13.913] 2MASS Ks band magnitude
270-274 F5.3 mag e_Ksmag [0.015/0.057] Uncertainty in Ksmag
276-280 F5.3 0.1pm EW(Li) [0.058/0.739]? Lithium 6707Å equivalent
width (G1)
282-287 F6.2 0.1pm EW(Ha) [-82.28/1.63] Hα equivalent width (G1)
289-293 F5.2 [10-7W] logLX [27.56/31.9]? Log X-ray luminosity (in erg/s)
295-298 F4.2 [10-7W] e_logLX [0.01/0.68]? Uncertainty in logLX (in erg/s)
300-305 F6.3 mag FUVmag [14.114/23.571]? GALEX FUV band magnitude
307-311 F5.3 mag e_FUVmag [0.008/0.555]? Uncertainty in FUVmag
313-320 E8.2 --- FUV/J [4.52e-06/0.0178]? GALEX FUV to 2MASS J band
flux ratio
322-327 F6.3 mag NUVmag [13.722/23.45]? GALEX NUV band magnitude
329-333 F5.3 mag e_NUVmag [0.004/0.549]? Uncertainty in NUVmag
335-342 E8.2 --- NUV/J [3.29e-05/0.0442]? GALEX NUV to 2MASS J band
flux ratio
--------------------------------------------------------------------------------
Note (1): Reference as follows:
1 = Riaz et al. (2006, J/AJ/132/866);
2 = Reid et al. (1995, Cat. III/198);
3 = Hawley et al. (1996, Cat. III/198);
4 = Cruz et al. (2003, J/AJ/126/2421);
6 = Thackrah et al. (1997MNRAS.284..507T 1997MNRAS.284..507T);
7 = Reid et al. (2004, J/AJ/128/463);
8 = Gaidos et al. (2014, J/MNRAS/443/2561);
9 = Kirkpatrick et al. (2008, J/ApJ/689/1295);
10 = Reyle et al. (2006, J/MNRAS/373/705);
11 = West et al. (2008, J/AJ/135/785);
12 = Faherty et al. (2016, J/ApJS/225/10);
13 = This work;
14 = Gagne et al. (2015, J/ApJS/219/33);
15 = Torres et al. (2006, J/A+A/460/695);
16 = Song et al. (2004ApJ...600.1016S 2004ApJ...600.1016S);
17 = Pecaut & Mamajek (2013, J/ApJS/208/9);
18 = Gray et al. (2006, J/AJ/132/161);
19 = Reid et al. (2003, J/AJ/126/3007);
20 = Stocke et al. (1991, Cat. IX/15);
21 = Cook et al. (2016, J/MNRAS/457/2192);
23 = Lepine & Gaidos (2011, J/AJ/142/138);
24 = Best et al. (2018, J/ApJS/234/1);
25 = Schneider et al. (2012ApJ...757..163S 2012ApJ...757..163S);
26 = Rodriguez et al. (2011ApJ...727...62R 2011ApJ...727...62R);
28 = Cutispoto et al. (1996, J/A+AS/115/41);
29 = Binks et al. (2015, J/MNRAS/452/173);
32 = Nefs et al. (2012MNRAS.425..950N 2012MNRAS.425..950N).
Note (2): Reference as follows:
b = Riedel et al. (2014, J/AJ/147/85);
d = Finch et al. (2014, J/AJ/148/119) (photometric);
f = Janson et al. (2012, J/ApJ/754/44) (photometric);
h = Bell et al. (2015, J/MNRAS/454/593) (statistical);
i = Dittmann et al. (2014, J/ApJ/784/156);
j = Lepine & Gaidos (2011, J/AJ/142/138) (photometric);
k = Reid et al. (2003, J/AJ/126/3007) (photometric);
m = Riaz et al. (2006, J/AJ/132/866) (photometric, 20% uncertainty assumed);
n = Finch et al. (2018, Cat. I/344);
p = Kunder et al. (2017, Cat. III/279);
q = Winters et al. (2017, J/AJ/153/14);
r = van der Marel et al. (2016, J/A+A/592/A126) (photometric, 20% uncertainty
assumed);
s = Distance from Gould & Chaname (2004, J/ApJS/150/455).
Note (3): Reference as follows:
c = Finch & Zacharias (2016, J/AJ/151/160);
e = Zacharias et al. (2017, Cat. I/340);
g = Zacharias et al. (2013, Cat. I/322);
l = Tian et al. (2017, Cat. I/343);
o = Finch et al. (2018, Cat. I/344).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs)
18- 44 A27 --- OName Other identifier
46- 59 A14 --- T/I Telescope/Instrument used
61- 71 A11 "date" Date UT date of the observation
73- 79 F7.2 km/s RV [-179.03/151.53] Radial velocity
81- 85 F5.2 km/s e_RV [0.08/11.13] Uncertainty in RV
87- 90 A4 --- SB Spectroscopic binary?
92 A1 --- f_SB [s] Flag on SB (1)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
s = Star observed more than once with no RV variations.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs)
18- 24 F7.2 km/s RV [-132.01/115.97] Radial velocity from this work
26- 30 F5.2 km/s e_RV [0.09/35.42] Uncertainty in RV
32- 38 F7.2 km/s RV-lit [-164.62/144.42] Literature radial velocity
40- 45 F6.2 km/s e_RV-lit [0.01/117.2]? Uncertainty in RV-lit
47- 48 I2 --- r_RV-lit [1/65] Reference code for RV-lit (see refs.dat
file)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Syst [1/69] System number
4- 7 F4.1 --- Comp [1.1/69.2] Companion number
9- 23 F15.11 deg RAdeg Gaia DR2 Right Ascension (ICRS) at Ep=2015.5
25- 39 F15.11 deg DEdeg Gaia DR2 Declination (ICRS) at Ep=2015.5
41- 47 F7.4 mas Plx [4.0776/85.8373] Parallax
49- 54 F6.4 mas e_Plx [0.0188/1.5383] Uncertainty in Plx
56- 63 F8.3 mas/yr pmRA [-396.396/677.548] Proper motion along RA
(pmRA*cosDE)
65- 69 F5.3 mas/yr e_pmRA [0.023/2.782] Uncertainty in pmRA
71- 78 F8.3 mas/yr pmDE [-377.302/481.326] Proper motion along DE
80- 84 F5.3 mas/yr e_pmDE [0.027/3.049] Uncertainty in pmDE
86- 90 F5.1 arcsec Sep1 [1/375]? Separation in arcsec
92- 96 I5 AU Sep2 [16/19937]? Separation in AU
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat table7.dat table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Group Moving group identifier
15- 30 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs)
31 A1 --- m_2MASS [AB] Multiplicity index on 2MASS (only in
Table 7)
33- 37 A5 --- SpType Spectral type
39- 43 F5.3 0.1pm EW(Li) [0.073/0.739]? Lithium 6707Å equivalent
width (G1)
45- 50 F6.2 0.1pm EW(Ha) [-63.46/1.49] Hα equivalent width (G1)
52- 56 F5.2 [10-7W] logLX [28.26/31.36]? Log X-ray luminosity (in erg/s)
58- 61 F4.2 [10-7W] e_logLX [0.03/0.33]? Uncertainty in logLX (in erg/s)
63- 70 E8.3 --- FUV/J [1.02e-05/0.000188]? GALEX FUV to 2MASS J band
flux ratio
72- 79 E8.3 --- NUV/J [5.45e-05/0.000772]? GALEX NUV to 2MASS J band
flux ratio
81- 87 F7.2 pc X [-454.65/74.7] X coordinate
89- 96 F8.2 pc Y [-1268.7/18.73] Y coordinate
98-104 F7.2 pc Z [-419.99/143.77] Z coordinate
106-111 F6.2 km/s U [-59.23/10.52] Velocity towards Galactic
center
113-118 F6.2 km/s V [-79.45/13.84] Velocity in direction of
Galactic rotation
120-125 F6.2 km/s W [-54.38/18.89] Velocity toward North Galactic
Pole
127-131 F5.1 % BANYAN [1.3/100]? The BANYAN Σ percentage
(only in Table 6) (1)
133 A1 --- Memb New member? (not in Table 8) (2)
135 A1 --- n_Memb [bcdef] Note on Memb (only in Table 6) (3)
137-140 F4.2 pc sigDist [1.07/8.84]? Distance σ difference
σdist (only in Table 8) (4)
142-145 F4.2 km/s sigRV [0.16/5.85]? Radial velocity σ
difference σRV (only in Table 8) (4)
--------------------------------------------------------------------------------
Note (1): We evaluate each object for potential moving group membership using
the BANYAN Σ tool (Gagne et al. 2018, J/ApJ/856/23), which evaluates
the membership probabilities by comparing positions to known members of
different groups using a Bayesian classifier. BANYAN Σ considers all
kinematic information (position, proper motion, parallax, and radial velocity)
to compare six-dimensional XYZUVW coordinates to known groups using
multivariate Gaussians.
Note (2): Member defined as follows:
Y = Completely new member;
R = Reassigned member (i.e., those objects previously proposed to belong to
a different group).
Note (3): Note as follows:
b = Previously suggested to be a member of the Columba association in
Malo et al. (2013, J/ApJ/762/88; 2014, J/ApJ/788/81);
c = Previously suggested to be a member of the Argus association in
Malo et al. (2013, J/ApJ/762/88);
d = Previously suggested to be a member of the Scorpius-Centaurus OB
association in Rodriguez et al. (2011ApJ...727...62R 2011ApJ...727...62R);
e = Previously suggested to be a member of the Argus association in
Riedel et al. (2014, J/AJ/147/85);
f = Previously suggested as an ambiguous AB Dor/β Pic/Carina/Columbia
candidate group in Malo et al. (2013, J/ApJ/762/88).
Note (4): We include the σ difference between the optimal distance and
radial velocity values from BANYAN Σ and those measured in this work
defined as the difference between the optimal and measured values divided by
the combined uncertainty.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Ref [1/65] Reference code
4- 35 A32 --- Aut Author's name(s)
37- 55 A19 --- Bibcode Bibcode of the reference
--------------------------------------------------------------------------------
Global notes:
Note (G1): In units of milli-Angstroms.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Kraus et al. Paper I. 2014AJ....147..146K 2014AJ....147..146K, Cat. J/AJ/147/146
Shkolnik et al. Paper II. 2017AJ....154...69S 2017AJ....154...69S, Cat. J/AJ/154/69
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 16-Aug-2019