J/ApJ/840/87 Young star systems observed with SALT (Riedel+, 2017)
Young stars with SALT.
Riedel A.R., Alam M.K., Rice E.L., Cruz K.L., Henry T.J.
<Astrophys. J., 840, 87 (2017)>
=2017ApJ...840...87R 2017ApJ...840...87R
ADC_Keywords: Radial velocities ; Spectral types ; Equivalent widths ;
Stars, nearby
Keywords: open clusters and associations: general; solar neighborhood;
stars: low-mass; stars: pre-main sequence; techniques: spectroscopic
Abstract:
We present a spectroscopic and kinematic analysis of 79 nearby M
dwarfs in 77 systems. All of these dwarfs are low-proper-motion
southern hemisphere objects and were identified in a nearby star
survey with a demonstrated sensitivity to young stars. Using
low-resolution optical spectroscopy from the Red Side Spectrograph on
the South African Large Telescope, we have determined radial
velocities, H-alpha, lithium 6708Å, and potassium 7699Å
equivalent widths linked to age and activity, and spectral types for
all of our targets. Combined with astrometric information from
literature sources, we identify 44 young stars. Eighteen are
previously known members of moving groups within 100pc of the Sun.
Twelve are new members, including one member of the TW Hydra moving
group, one member of the 32 Orionis moving group, 9 members of Tucana-
Horologium, one member of Argus, and two new members of AB Doradus. We
also find 14 young star systems that are not members of any known
groups. The remaining 33 star systems do not appear to be young. This
appears to be evidence of a new population of nearby young stars not
related to the known nearby young moving groups.
Description:
The sample of stars was drawn from the TINYMO survey (Riedel
2012PhDT.......100R 2012PhDT.......100R). In that survey, nearby low-proper-motion M
dwarfs in the southern hemisphere were identified in the SuperCOSMOS
Science Archive (Hambly+ 2001MNRAS.326.1279H 2001MNRAS.326.1279H).
We have obtained low-resolution optical spectroscopy from the SALT
telescope at the South African Astronomical Observatory in Sutherland,
South Africa and the Robert Stoble Spectrograph (RSS), which provides
optical spectroscopy between 3200 and 9000Å with a resolving power
of up to 6000, depending on slit width. Observations were conducted in
semesters 2013A and 2013B.
In total, there are 165 spectra of the 79 stars: SCR 2237-2622 was
only observed once, two stars (SCR 1816-6305, 2MASS 2004-3356) were
observed three times, three stars (2MASS 0510-2340B, 2MASS 1207-3247,
SCR 1842-5554A) were observed four times, and the remainder were
observed twice.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 310 79 Previously published astrometry and photometry
table2.dat 80 79 Radial velocities and spectral types
table4.dat 76 13 UVWXYZ space velocities and positions
table5.dat 83 79 Youth properties
table6.dat 83 177 SALT equivalent widths for 86 unique stars
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See also:
III/227 : General Catalog of galactic Carbon stars, 3d Ed. (Alksnis+ 2001)
I/297 : NOMAD Catalog (Zacharias+ 2005)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/317 : The PPMXL Catalog (Roeser+ 2010)
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
J/ApJS/141/503 : Radial Velocities for 889 late-type stars (Nidever+, 2002)
J/AJ/132/866 : New M dwarfs in solar neighborhood (Riaz+, 2006)
J/A+A/460/695 : Associations Containing Young stars (Torres+, 2006)
J/AN/328/889 : Mean Radial Velocities of open clusters (Kharchenko+, 2007)
J/AJ/134/2340 : Membership of Praesepe & Coma Berenices (Kraus+, 2007)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/ApJS/184/138 : XID II: RASS-2MASS cross-association (Haakonsen+, 2009)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/AJ/140/119 : βPic & AB Dor moving groups members (Schlieder+, 2010)
J/ApJ/758/56 : Young M dwarfs within 25pc. II. Kinematics (Shkolnik+, 2012)
J/ApJ/762/88 : Young stellar kinematic group cand. members (Malo+, 2013)
J/MNRAS/435/1325 : Membership of the ε Cha association (Murphy+, 2013)
J/ApJ/783/121 : BANYAN II. Nearby young assoc. cand. members (Gagne+, 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/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/ApJ/798/73 : BANYAN All-Sky Survey (BASS) catalog. V. YMGs (Gagne+, 2015)
J/MNRAS/447/1267 : Low-mass members of the Octans association (Murphy+, 2015)
J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)
http://www.recons.org/ : Research Consortium on Nearby Stars
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 -- Name Shortened Object Name
18- 27 A10 -- UCAC4 UCAC4 Designation
29- 37 F9.5 deg RAdeg [4.3/355.1] Right Ascension (J2000)
39- 41 I3 mas e_RAdeg [5/128] Uncertainty on RAdeg
43- 51 F9.5 deg DEdeg [-71/-6] Declination (J2000)
53- 55 I3 mas e_DEdeg [3/115] Uncertainty on DEdeg
57- 62 F6.1 mas/yr pmRA [-278/263] Proper motion, Right Ascension (1)
64- 67 F4.1 mas/yr e_pmRA Uncertainty on pmRA (1)
69- 74 F6.1 mas/yr pmDE [-234/126] Proper motion, Declination
76- 79 F4.1 mas/yr e_pmDE Uncertainty on pmDE
81- 85 A5 -- r_pmRA Source of position and proper motion (2)
87- 91 F5.2 mag Vmag [11.4/14.7] Johnson V magnitude
93- 96 F4.2 mag e_Vmag [0.01/0.3]? Uncertainty on Vmag
98-105 A8 -- r_Vmag Source of Vmag (2)
107-110 F4.2 mag Ksmag [6.7/9.2] 2MASS Ks magnitude
112-115 F4.2 mag e_Ksmag [0.02/0.04] Uncertainty on Ksmag
117-121 A5 -- r_Ksmag Source of Ksmag (2)
123-127 F5.2 mas plx [14.9/53.2]? Parallax
129-132 F4.2 mas e_plx [0.2/2.7]? Uncertainty on plx
134-148 A15 -- r_plx Source of plx (3)
150-156 F7.2 km/s HRV [-205/37] Heliocentric Radial Velocity
from this paper
158-162 F5.2 km/s e_HRV [0.8/13] Uncertainty on HRV
164-168 F5.2 km/s HRVl [-10/25]? Heliocentric Radial Velocity
from other papers
170-174 F5.2 km/s e_HRVl [0.02/20]? Uncertainty on HRVlit
176-189 A14 -- r_HRVl Source of HRVlit (4)
191-197 A7 -- SpT Spectral Type on MK system from this paper
199-201 A3 -- f_SpT Flag on 2MASS 0510-2340B' spectral type (5)
203-207 F5.3 0.1nm EWLi [0.18/0.4]? Equivalent width of unresolved
Li 6708Å doublet
209-213 F5.3 0.1nm e_EWLi [0.001/0.04]? Uncertainty on EWLi
215-220 F6.3 0.1nm EWKI [-0.07/1.8] Equivalent width of K 7699Å line
222-225 F4.2 0.1nm e_EWKI [0/0.4] Uncertainty on EWKI
227-232 F6.2 0.1nm EWHa [-18/0.07] Equivalent width of
H-alpha 6563Å line
234-237 F4.2 0.1nm e_EWHa [0/1.3] Uncertainty on EWHa
239 A1 -- f_EWLi [L] Youth flag based on lithium (6)
241 A1 -- f_EWKI [K] Youth flag based on potassium (6)
243 A1 -- f_EWHa [h] Youth flag based on H-alpha (6)
245-252 A8 -- Groupl Moving group identification in literature
254-271 A18 -- r_Groupl Source of groupLit (7)
273-280 A8 -- Group LACEwING moving group identification
282 A1 -- f_Group [*] *: star was originally identified as
a member of a different group
284-286 I3 % q_Group [0/100]? Probability of group
288-292 F5.2 pc kDist [21/88]? LACEwING kinematic distance estimate
294-298 F5.2 pc e_kDist [0.1/11]? Uncertainty on kinDist
300-305 F6.2 km/s kHRV [-19/24]? LACEwING kinematic radial velocity
estimate
307-310 F4.2 km/s e_kHRV [0.3/4]? Uncertainty on kinHRV
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Note (1): pmRA is actually pmRA*cos(DEJ2000) everywhere it appears.
Note (2): Sources of magnitudes, positions and proper motions as follows:
2MASS = Two Micron All Sky Survey, Cutri+ (2003, II/246);
APASSDR9 = All Sky Survey Data Release 9, Henden+ (II/336);
NOMAD = Naval Observatory Merged Astrometric Dataset,
Zacharias+ (2005, I/297);
PPMXL = PPMXL, Roser+ (2010, I/317);
UCAC4 = Fourth U.S. Naval Observatory CCD Astrograph Catalog,
Zacharias+ (2013, I/322)
Note (3): Source of parallax as follows:
Riedel2014 = Riedel et al. (2014, J/AJ/147/85);
Shkolnik2012 = Shkolnik et al. (2012, J/ApJ/758/56);
Weinberger2013 = Weinberger et al. (2013ApJ...762..118W 2013ApJ...762..118W);
van-Leeuwen2007 = van Leeuwen (2007, I/311).
Note (4): Source of heliocentric radial velocity as follows:
Kraus2014 = Kraus et al. (2014ApJ...781...20K 2014ApJ...781...20K);
Looper2010 = Looper et al. (2010ApJ...714...45L 2010ApJ...714...45L);
Malo2013 = Malo et al. (2013, J/ApJ/762/88);
Malo2014a = Malo et al. (2014, J/ApJ/788/81);
Nidever2002 = Nidever et al. (2002, J/ApJS/141/503);
Riedel2014 = Riedel et al. (2014, J/AJ/147/85);
Schneider2012a = Schneider et al. (2012ApJ...754...39S 2012ApJ...754...39S);
Shkolnik2012 = Shkolnik et al. (2012, J/ApJ/758/56);
Torres2006 = Torres et al. (2006, J/A+A/460/695).
Note (5):
(!) = We find one member of the Columba moving group: 2MASS 0510-2340AB.
It was identified as such by Malo+ (2013, J/ApJ/762/88) and we
reproduce that membership for both components. Despite being the
fainter star of the pair, the B component has an earlier spectral type
both here and in Malo+ (2013, J/ApJ/762/88). This would suggest that
they are actually two separate star systems, but their proper motions,
kinematic distances, and RVs are identical at the 1σ level, and
they are separated by only 27 arcsec.
More study of this system is needed.
Note (6): Membership flags are based on spectroscopic analysis (see Section 5)
and are given as follows:
L = detectable lithium absorption (f_EWLi);
K = potassium EW below standard deviation of field value (f_EWKI);
h = Hα emission stronger than -10Å (f_EWHa).
Note (7): Source of moving group identification. Membership references are to
the first paper that identified the object as a member.
References as follows:
deLaReza1989 = de la Reza et al. (1989ApJ...343L..61D 1989ApJ...343L..61D);
Gagne2015a = Gagne et al. (2015, J/ApJ/798/73);
Gregorio-Hetem1992 = Gregorio-Hetem et al. (1992AJ....103..549G 1992AJ....103..549G);
Kiss2011 = Kiss et al. (2011MNRAS.411..117K 2011MNRAS.411..117K);
Kraus2014 = Kraus et al. (2014ApJ...781...20K 2014ApJ...781...20K);
Looper2010 = Looper et al. (2010ApJ...714...45L 2010ApJ...714...45L);
Malo2013 = Malo et al. (2013, J/ApJ/762/88);
Riedel2014 = Riedel et al. (2014, J/AJ/147/85);
Rodriguez2013 = Rodriguez et al. (2013ApJ...774..101R 2013ApJ...774..101R);
Shkolnik2012 = Shkolnik et al. (2012, J/ApJ/758/56);
Song2003 = Song et al. (2003ApJ...599..342S 2003ApJ...599..342S);
Sterzik1999 = Sterzik et al. (1999A&A...346L..41S 1999A&A...346L..41S);
Torres2000 = Torres et al. (2000AJ....120.1410T 2000AJ....120.1410T);
Webb1999 = Webb et al. (1999ApJ...512L..63W 1999ApJ...512L..63W);
Zuckerman2001 = Zuckerman et al. (2001ApJ...559..388Z 2001ApJ...559..388Z).
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Comp [CX] Comparison stars (8)
3- 18 A16 --- Name Shortened Object Name; see Table 1 for UCAC4
identifiers
20 A1 --- G [1] Giant Flag (1= Star flagged as Giant)
22- 23 I2 h RAh [0/23] Hour of Right Ascension (J2000)
25- 26 I2 min RAm Minute of Right Ascension (J2000)
28- 32 F5.2 s RAs Second of Right Ascension (J2000)
34 A1 --- DE- [-] Sign of the Declination (J2000)
35- 36 I2 deg DEd [6/70] Degree of Declination (J2000)
38- 39 I2 arcmin DEm Arcminute of Declination (J2000)
41- 44 F4.1 arcsec DEs Arcsecond of Declination (J2000)
46- 52 A7 --- SpT MK Spectral Type
54- 59 F6.1 km/s HRV [-205/37] Heliocentric Radial Velocity; this paper
61- 64 F4.1 km/s e_HRV [0.9/12.1] Uncertainty on HRV
66- 72 F7.3 km/s HRVl [-10/25]? Heliocentric Radial Velocity; literature
74- 78 F5.2 km/s e_HRVl [0.02/20]? Uncertainty on HRVl
80 A1 --- r_HRVl Source of HRVl (9)
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Note (8): Flag as follows:
C = used for RV fitting;
X = rejected for RV fitting
Note (9): Source of HRVlit as follows:
1 = Malo et al. (2013, J/ApJ/762/88);
2 = Shkolnik et al. (2012, J/ApJ/758/56);
3 = Kraus et al. (2014ApJ...781...20K 2014ApJ...781...20K);
4 = Malo et al. (2014, J/ApJ/788/81);
5 = Torres et al. (2006, J/A+A/460/695);
6 = Riedel et al. (2014, J/AJ/147/85);
7 = Looper et al. (2010ApJ...714...45L 2010ApJ...714...45L);
8 = Schneider et al. (2012ApJ...754...39S 2012ApJ...754...39S);
9 = Nidever et al. (2002, J/ApJS/141/503).
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Name Shortened Object Name; see Table 1 for UCAC4
identifiers
18- 22 F5.1 km/s U U Galactic space motion(1)
24- 26 F3.1 km/s e_U Uncertainty in U (1)
28- 32 F5.1 km/s V V Galactic space motion(1)
34- 36 F3.1 km/s e_V Uncertainty in V (1)
38- 42 F5.1 km/s W W Galactic space motion(1)
44- 46 F3.1 km/s e_W Uncertainty in W (1)
48- 52 F5.1 pc X X Galactic coordinate(1)
54- 56 F3.1 pc e_X Uncertainty in X (1)
58- 62 F5.1 pc Y Y Galactic coordinate(1)
64- 66 F3.1 pc e_Y Uncertainty in Y (1)
68- 72 F5.1 pc Z Z Galactic coordinate(1)
74- 76 F3.1 pc e_Z Uncertainty in Z (1)
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Note (1): All values computed using right-handed coordinates, where U/X is
toward the center of the Galaxy, V/Y in the direction of motion, and
W/Z toward the north Galactic pole.
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Name Shortened Object Name; see Table 1 for UCAC4
identifiers
18- 22 A5 --- FYth [ ,KLh] Youth flag(s) (10)
24- 33 A10 --- groupL Moving group identification in literature
35- 36 I2 --- r_groupL ? Source of groupLit (11)
38- 47 A10 --- group LACEwING moving group identification
49- 51 I3 % q_group [0/100]? Probability of group
53- 56 F4.1 pc kDist [21.5/87.6]? LACEwING kinematic distance estimate
58- 61 F4.1 pc e_kDist [0.1/10.6]? Uncertainty on kDist
63- 67 F5.1 km/s kHRV [-18.4/23.4]? LACEwING kinematic
radial velocity estimate
69- 71 F3.1 km/s e_kHRV [0.4/4]? Uncertainty on kinHRV
73- 77 F5.1 km/s HRV [-37/37]? Heliocentric Radial Velocity;
this paper
79- 81 F3.1 km/s e_HRV [0.9/8]? Uncertainty on HRV
83 A1 --- Fmg [1] Moving group match flag (12)
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Note (10): Youth and membership flags based on lithium, potassium and Hα
spectroscopic analysis (see Section 5) as follows:
L = detectable lithium absorption;
K = potassium EW below standard deviation of field value;
h = Hα emission stronger than -10Å.
Note (11): Membership references are to the first paper that identified the
object as a member. Reference codes as follows:
1 = Malo et al. (2013, J/ApJ/762/88);
2 = Riedel et al. (2014, J/AJ/147/85);
3 = Zuckerman et al. (2001ApJ...559..388Z 2001ApJ...559..388Z);
4 = Shkolnik et al. (2012, J/ApJ/758/56);
5 = Kiss et al. (2011MNRAS.411..117K 2011MNRAS.411..117K);
6 = Rodriguez et al. (2013ApJ...774..101R 2013ApJ...774..101R);
7 = Torres et al. (2000AJ....120.1410T 2000AJ....120.1410T);
8 = Kraus et al. (2014ApJ...781...20K 2014ApJ...781...20K);
9 = de la Reza et al. (1989ApJ...343L..61D 1989ApJ...343L..61D);
10 = Sterzik et al. (1999A&A...346L..41S 1999A&A...346L..41S);
11 = Gregorio-Hetem et al. (1992AJ....103..549G 1992AJ....103..549G);
12 = Looper et al. (2010ApJ...714...45L 2010ApJ...714...45L);
13 = Webb et al. (1999ApJ...512L..63W 1999ApJ...512L..63W);
14 = Song et al. (2003ApJ...599..342S 2003ApJ...599..342S);
15 = Gagne et al. (2015, J/ApJ/798/73).
Note (12):
1 = Initial match was to a different moving group;
see Section 6 for details.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Set Target flag ("target": young star; or
"standard": flux standard, 12 occurrences)
10- 25 A16 --- Name Shortened Object Name; see Table 1 for UCAC4
identifiers
27- 36 A10 "Y/M/D" ObsDate Observation UT Date
38- 43 F6.2 0.1nm EWHa-o [-18/1] Equivalent width, Hα 6563Å,
measured on ObsDate
45- 50 F6.2 0.1nm EWHa-w [-18/1]? Equivalent width, Hα 6563Å,
weighted average
52- 55 F4.2 0.1nm e_EWHa-w [0.01/1.1]? Uncertainty in EWHa-w,
weighted average
57- 59 I3 10-13m EWLi-o [-91/409]? Equivalent width,
unresolved Li 6708Å doublet,
measured on ObsDate
61- 63 I3 10-13m EWLi-w [64/396]? Equivalent width,
unresolved Li 6708Å doublet,
weighted average
65- 66 I2 10-13m e_EWLi-w [1/37]? Uncertainty in EWLi-w, weighted average
68- 72 F5.2 0.1nm EWKI-o [-2/2] Equivalent width, K 7699Å,
measured on ObsDate
74- 78 F5.2 0.1nm EWKI-w [-1/2]? Equivalent width, K 7699Å,
weighted average
80- 83 F4.2 0.1nm e_EWKI-w [0.01/0.6]? Uncertainty in EWKI-w,
weighted average
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Dec-2017