J/ApJS/220/18 BDKP IV. RVs of late-M and L dwarfs with MagE (Burgasser+, 2015)
The brown dwarf kinematics project (BDKP).
IV. Radial velocities of 85 late-M and L dwarfs with MagE.
Burgasser A.J., Logsdon S.E., Gagne J., Bochanski J.J., Faherty J.K.,
West A.A., Mamajek E.E., Schmidt S.J., Cruz K.L.
<Astrophys. J. Suppl. Ser., 220, 18 (2015)>
=2015ApJS..220...18B 2015ApJS..220...18B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Radial velocities ; Spectral types ;
Proper motions ; Equivalent widths
Keywords: brown dwarfs; methods: statistical; stars: kinematics and dynamics;
stars: low-mass; techniques: radial velocities
Abstract:
Radial velocity measurements are presented for 85 late M- and L-type
very low-mass stars and brown dwarfs obtained with the Magellan
Echellette spectrograph. Targets primarily have distances within 20pc
of the Sun, with more distant sources selected for their unusual
spectral energy distributions. We achieved precisions of 2-3km/s, and
combined these with astrometric and spectrophotometric data to
calculate UVW velocities. Most are members of the thin disk of the
Galaxy, and velocity dispersions indicate a mean age of 5.2±0.2Gyr
for sources within 20pc. We find significantly different kinematic
ages between late-M dwarfs (4.0±0.2Gyr) and L dwarfs (6.5±0.4Gyr)
in our sample that are contrary to predictions from prior simulations.
This difference appears to be driven by a dispersed population of
unusually blue L dwarfs which may be more prevalent in our local
volume-limited sample than in deeper magnitude-limited surveys. The L
dwarfs exhibit an asymmetric U velocity distribution with a net inward
flow, similar to gradients recently detected in local stellar samples.
Simulations incorporating brown dwarf evolution and Galactic orbital
dynamics are unable to reproduce the velocity asymmetry, suggesting
non-axisymmetric perturbations or two distinct L dwarf populations. We
also find the L dwarfs to have a kinematic age-activity correlation
similar to more massive stars. We identify several sources with low
surface gravities, and two new substellar candidate members of nearby
young moving groups: the astrometric binary DENIS J08230313-4912012AB,
a low-probability member of the β Pictoris Moving Group; and
2MASS J15104786-2818174, a moderate-probability member of the 30-50Myr
Argus Association.
Description:
All sources were observed with the MagE spectrograph, mounted on the
Magellan 6.5m Landon Clay Telescope at Las Campanas Observatory. Data
were obtained in 15 nights over a 2.5-year period (2008 November
through 2011 March); 3200-10050Å at an average resolution ∼4100.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 144 85 Observational sample
table3.dat 134 85 Equivalent widths and line strengths of
absorption and emission lines
table6.dat 88 85 Radial velocity measurements
table7.dat 68 85 Final radial velocities and heliocentric
space motions
refs.dat 75 52 References
--------------------------------------------------------------------------------
See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
I/317 : The PPMXL Catalog (Roeser+ 2010)
III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)
J/MNRAS/447/1267 : Low-mass members of the Octans association (Murphy+, 2015)
J/ApJ/798/73 : BANYAN All-Sky Survey (BASS) catalog. V. (Gagne+, 2015)
J/AJ/147/146 : Spectroscopy of Tuc-Hor candidate members (Kraus+, 2014)
J/AJ/147/94 : Solar neighborhood. XXXII. L and M dwarfs (Dieterich+, 2014)
J/ApJ/783/121 : BANYAN II. Nearby young assoc. cand. members (Gagne+, 2014)
J/A+A/556/A133 : DENIS-P J082303.1-49120 astrometric orbit (Sahlmann+, 2013)
J/ApJ/753/156 : T/Y brown dwarfs with WISE photometry (Kirkpatrick+, 2012)
J/ApJ/752/56 : BDKP. III. Parallaxes for ultracool dwarfs (Faherty+, 2012)
J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)
J/ApJ/723/684 : NIRSPEC ultracool dwarf RV survey (Blake+, 2010)
J/ApJS/190/100 : NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)
J/AJ/139/1808 : Colors and kinematics of SDSS L dwarfs (Schmidt+, 2010)
J/A+A/512/A37 : Velocities of 43 nearby L dwarfs (Seifahrt+, 2010)
J/ApJ/705/1416 : Volume-limited sample of M7-M9.5 dwarfs (Reiners+, 2009)
J/ApJ/695/1591 : Spectrophotometry in PEARS fields (Pirzkal+, 2009)
J/AJ/137/1 : Pap. I: pm & astrometry of late-type dwarfs (Faherty+, 2009)
J/ApJ/689/1295 : Lithium test implications for BD* (Kirkpatrick+, 2008)
J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/MNRAS/383/831 : New DENIS nearby L and late-M dwarfs (Phan-Bao+, 2008)
J/ApJ/667/520 : Proper motions in multiple systems (Caballero, 2007)
J/A+A/468/163 : Sample of low mass stars with mu>0.1"/yr (Deacon+, 2007)
J/AJ/133/2258 : Activity and kinematics of ultracool dwarfs (Schmidt+, 2007)
J/AJ/133/439 : Luminosity function of M7-L8 ultracool dwarfs (Cruz+, 2007)
J/A+A/460/695 : Associations Containing Young stars search (Torres+, 2006)
J/AJ/132/663 : Differential Velocities of very low mass SBs (Basri+, 2006)
J/AJ/130/1871 : Spectroscopic survey of M dwarfs (Bochanski+, 2005)
J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)
J/A+A/440/1061 : Southern red high proper motion objects (Lodieu+, 2005)
J/other/ARA+A/42.685 : Young stars near the Sun (Zuckerman+, 2004)
J/AJ/128/426 : Subdwarfs in the SDSS (West+, 2004)
J/AJ/127/3553 : JHK phot. & spectroscopy for L and T dwarfs (Knapp+, 2004)
J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)
J/A+A/410/527 : Abundances in the Galactic disk (Bensby+, 2003)
J/MNRAS/301/1031 : High resolution spectra of VLM stars (Tinney+ 1998)
http://spider.ipac.caltech.edu/staff/davy/ARCHIVE/index.shtml/ :
DwarfArchives.org
http://jgagneastro.wordpress.com/list-of-ultracool-dwarfs/ : list of ultracool
dwarfs
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Source name (JHHMM+DDMMAA)
14- 15 I2 h RAh Hour of Right Ascension (J2000)
17- 18 I2 min RAm Minute of Right Ascension (J2000)
20- 24 F5.2 s RAs Second of Right Ascension (J2000)
26 A1 --- DE- Sign of the Declination (J2000)
27- 28 I2 deg DEd Degree of Declination (J2000)
30- 31 I2 arcmin DEm Arcminute of Declination (J2000)
33- 36 F4.1 arcsec DEs Arcsecond of Declination (J2000)
39- 42 A4 --- SpT Optical MK spectral type
44- 48 F5.2 mag Jmag [9.5/15.2] 2MASS J band magnitude
50- 53 F4.2 mag e_Jmag [0.02/0.05] Uncertainty in Jmag
55- 58 F4.2 mag J-Ks [0.8/2.1] 2MASS (J-KS) color index
60- 63 F4.2 mag e_J-Ks Uncertainty in J-Ks
65- 72 F8.2 mas/yr pmRA [-1176/2592] Proper motion along RA
74- 78 F5.2 mas/yr e_pmRA Uncertainty in pmRA
80- 86 F7.2 mas/yr pmDE [-993/760] Proper motion along DE
88- 92 F5.2 mas/yr e_pmDE Uncertainty in pmDE
94- 98 F5.2 pc Dist [3.8/42] Distance
100-103 F4.2 pc e_Dist [0.02/5] Uncertainty in Dist
105 A1 --- f_Dist [e] Flag on Dist (1)
107-112 F6.2 km/s RVp [-76/117]? Published radial velocity
114-117 F4.2 km/s e_RVp [0.06/5]? Uncertainty in RVp
119-129 A11 --- n_Name Source flag on Name (2)
131-144 A14 --- r_Name Reference(s) on Name (see refs.dat file:
1-12:source discovery; 21-50:source astrometry;
51-60:source RV measurements)
--------------------------------------------------------------------------------
Note (1):
e = A spectrophotometric estimate based on the MJ/spectral type
relation of Cruz et al. (2003, J/AJ/126/2421).
Note (2): Flag as follows:
VB = visual binary;
RV = radial velocity variable;
AB = astrometric binary;
Li = previous reported Li I absorption;
UB = unusually blue;
UR = unusually red;
betaPMG = previously identified member of β Pictoris Moving Group;
CAS = previously identified member of Caster Moving Group;
HYA = previously identified member of Hyades Moving Group;
THA = previously identified member of Tucana Horologium Association;
TWA = previously identified member of TW Hydrae Association;
UMA = previously identified member of Ursa Majoris.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Source name
14- 17 A4 --- SpT Optical MK spectral type
19 A1 --- l_LiI-6710 Limit flag on LiI-6710
20- 24 F5.2 0.1nm LiI-6710 [0.2/4] Li I 6710A line equivalent width (3)
26- 29 F4.2 0.1nm e_LiI-6710 ? Uncertainty in LiI-6710
31- 34 F4.2 0.1nm RbI-7802 [0.6/4.3] Rb I 7802A line equivalent width (3)
36- 39 F4.2 0.1nm e_RbI-7802 Uncertainty in RbI-7802
41 A1 --- l_RbI-7950 Limit flag on RbI-7950
42- 46 F5.2 0.1nm RbI-7950 [0.5/4.3] Rb I 7950A line equivalent width (3)
48- 51 F4.2 0.1nm e_RbI-7950 ? Uncertainty in RbI-7950
53- 56 F4.2 0.1nm NaI-8186 [0.8/2.3] Na I 8186A line equivalent width (3)
58- 61 F4.2 0.1nm e_NaI-8186 Uncertainty in NaI-8186
63- 66 F4.2 0.1nm NaI-8197 [0.9/2.5] Na I 8197A line equivalent width (3)
68- 71 F4.2 0.1nm e_NaI-8197 Uncertainty in NaI-8197
73 A1 --- l_CsI-8523 Limit flag on CsI-8523
74- 78 F5.2 0.1nm CsI-8523 [0.1/3.5] Cs I 8523A line equivalent width (3)
80- 83 F4.2 0.1nm e_CsI-8523 ? Uncertainty in CsI-8523
85 A1 --- l_CsI-8946 Limit flag on CsI-8946
86- 90 F5.2 0.1nm CsI-8946 [0.5/2.2] Cs I 8946A line equivalent width (3)
92- 95 F4.2 0.1nm e_CsI-8946 ? Uncertainty in CsI-8946
97 A1 --- l_Ha Limit flag on Ha
98-103 F6.2 0.1nm Ha [-53/-0.1] Hα line equivalent width (3)
105-109 F5.2 0.1nm e_Ha [0.1/20]? Uncertainty in Ha
111 A1 --- l_logLHa Limit flag on logLHa
112-117 F6.2 [-] logLHa [-7.3/-3.9] Log Hα to bolometric
luminosity ratio
119-122 F4.2 [-] e_logLHa [0.06/0.2]? Uncertainty in logLHa
124-128 F5.3 --- zeta [0.5/1.4]? Metallicity index
130-134 F5.3 --- e_zeta [0.003/0.06]? Uncertainty in ζ
--------------------------------------------------------------------------------
Note (3): In units of Angstroms.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Source name
14 A1 --- f_Name [a] Flag on Name (4)
16- 19 A4 --- SpT Optical MK spectral type
21- 23 I3 km/s LCen [-65/117] Line center velocity
25- 26 I2 km/s e_LCen [2/22] Uncertainty in LCen
28- 32 F5.1 km/s SDSS [-69/115]? SDSS template radial velocity
34- 37 F4.1 km/s e_SDSS [0.6/18]? Uncertainty in SDSS
39- 43 F5.1 km/s MagE [-70.7/113.4] MagE standard radial velocity
45- 48 F4.1 km/s e_MagE [0.5/14] Uncertainty in MagE
50- 54 F5.1 km/s RVel [-71/114] Adopted radial velocity
56- 58 F3.1 km/s e_RVel [2/5] Uncertainty in RVel
60- 65 F6.2 km/s Prev1 [-76/116.4]? Previously measured radial velocity
67- 70 F4.2 km/s e_Prev1 [0.06/5]? Uncertainty in Prev1
72- 77 F6.2 km/s Prev2 [-53/80]? A second previously measured
radial velocity
79- 82 F4.2 km/s e_Prev2 [0.1/3]? Uncertainty in Prev2
84- 88 A5 --- Ref Reference(s) (5)
--------------------------------------------------------------------------------
Note (4):
a = Measured value differs by more than 3σ from previously
published value(s); see Section 3.1 and 3.4.
Note (5): References as follows:
1 = Blake et al. (2010, J/ApJ/723/684);
2 = Bochanski et al. (2005, J/AJ/130/1871);
3 = Galvez-Ortiz et al. (2010MNRAS.409..552G 2010MNRAS.409..552G);
4 = Mohanty & Basri (2003ApJ...583..451M 2003ApJ...583..451M);
5 = Reiners & Basri (2009, J/ApJ/705/1416);
6 = Schmidt et al. (2010, J/AJ/139/1808);
7 = Seifahrt et al. (2010, J/A+A/512/A37);
8 = Tinney & Reid (1998, J/MNRAS/301/1031);
9 = West et al. (2008, J/AJ/135/785);
10 = Tanner et al. (2012ApJS..203...10T 2012ApJS..203...10T).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Source name
14- 17 A4 --- SpT Optical MK spectral type
19- 21 I3 km/s RVel [-71/113] Adopted radial velocity
23 I1 km/s e_RVel [2/4] Uncertainty in RVel
25- 29 F5.1 km/s U [-67/78] Velocity toward Galactic center (6)
31- 33 F3.1 km/s e_U Uncertainty in U
35- 40 F6.2 km/s V [-92/58] Velocity in direction of
Galactic rotation (6)
42- 45 F4.2 km/s e_V Uncertainty in V
47- 53 F7.3 km/s W [-51/49] Velocity toward Galactic north pole (6)
55- 57 F3.1 km/s e_W Uncertainty in W
59- 63 F5.2 --- Prob [0.01/15] Relative probability of thick and
thin disk membership (7)
65- 68 A4 --- Pop Population code (8)
--------------------------------------------------------------------------------
Note (6): In the Local Standard of Rest frame.
Note (7): Memberships were assigned as thin disk (Prob<0.1), thick disk
(Prob>10) or intermediate thin/thick disk (0.1<Prob<10).
Note (8): Population code as follows:
D = thin disk;
TD = thick disk;
D/TD = intermediate between thin and thick disk.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode Bibcode
24- 43 A20 --- Auth Author's name(s)
45- 75 A31 --- Comm Comment
--------------------------------------------------------------------------------
History:
From electronic version of the journal
07-Dec-2015: Insert into VizieR
25-Apr-2017: Misprint on coordinates for J1315-2649AB corrected
(DEJ2000 = -26 49 51.3; not -26 49 5.13)
References:
Faherty et al. Paper I. 2009AJ....137....1F 2009AJ....137....1F Cat. J/AJ/137/1
Faherty et al. Paper II. 2010AJ....139..176F 2010AJ....139..176F
Faherty et al. Paper III. 2012ApJ...752...56F 2012ApJ...752...56F Cat. J/ApJ/752/56
Burgasser et al. Paper IV. 2015ApJS..220...18B 2015ApJS..220...18B This catalog
Hsu et al. Paper V. 2021ApJS..257...45H 2021ApJS..257...45H Cat. J/ApJS/257/45
Hsu et al. Paper VI. 2024ApJS..274...40H 2024ApJS..274...40H Cat. J/ApJS/274/40
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Nov-2015