J/MNRAS/402/575 Southern ultracool dwarfs in young moving groups (Clarke+, 2010) ================================================================================ A search for southern ultracool dwarfs in young moving groups. Clarke J.R.A., Pinfield D.J., Galvez-ortiz M.C., Jenkins J.S., Burningham B., Deacon N.R., Jones H.R.A., Pokorny R.S., Barnes J.R., Day-Jones A.C. =2010MNRAS.402..575C (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Associations, stellar ; Stars, dwarfs ; Stars, late-type ; Photometry, infrared ; Proper motions Keywords: stars: kinematics - stars: low-mass, brown dwarfs Abstract: We associate 132 low-mass ultracool dwarfs in the southern hemisphere as candidate members of five moving groups (MGs) using photometric and astrometric selection techniques. Of these objects, we present high-resolution spectroscopy for seven candidates and combine these with previous measurements from the literature to determine spectral types and radial velocities. We thus constrain distance and space motion spectroscopically, allowing the kinematic membership of the MGs to be assessed. Possible membership of MGs has allowed ages and metallicities to be constrained for these objects and evolutionary models have been used to estimate their mass. We estimate that up to ~75 of our candidate MG members should be genuine, and discuss future work that will confirm and exploit this major new sample. Description: We chose to consider the five MGs assessed in Montes et al. (2001, Cat. J/MNRAS/328/45), namely the Pleiades, Castor, Hyades, Sirius (also known as Ursa Major) and IC2391 MGs. By considering each MG in turn we have identified 132 objects that are candidate members of one or more of the five MGs. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 142 132 Properties of the 132 MG candidates -------------------------------------------------------------------------------- See also: J/MNRAS/328/45 : Late-type stars members of young groups (Montes+, 2001) Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 25 A25 --- Name Name 27- 31 F5.2 mag Jmag 2MASS J magnitude 33- 36 F4.2 mag e_Jmag rms uncertainty on Jmag 38- 41 F4.2 mag J-H 2MASS J-H colour index 43- 47 F5.2 mag e_J-H rms uncertainty on J-H 49- 52 F4.2 mag J-Ks 2MASS J-Ks colour index 54- 57 F4.2 mag e_J-Ks rms uncertainty on J-Ks 59- 62 F4.2 mag I-J I-J colour index (1) 64- 67 F4.2 mag e_I-J rms uncertainty on I-J 69- 73 F5.2 mag Rmag ?=- SUPERCOSMOS R magnitude (2) 75- 79 F5.1 mas/yr pmRA Proper motion along RA 81- 86 F6.1 mas/yr pmDE Proper motion along DE 88- 91 F4.1 mas/yr pm Total proper motion 93- 94 I2 pc bDist ? Lower value of photometric distance interval (3) 95 A1 --- --- [-] 96- 98 I3 pc BDist ? Upper value of photometric distance interval (3) 100-103 F4.1 pc Dist ? photometric Distance (3) 105-108 F4.1 pc E_Dist ? Error on Dist (upper value) 110-113 F4.1 pc e_Dist ? Error on Dist (lower value) 114 A1 --- n_Dist [defg] Note on Dist (4) 118-126 A9 --- SpType MK spectral type (5) 127 A1 --- n_SpType [fg] Note on SpType (4) 128-142 A15 --- MGmemb Potential moving groups membership (6) -------------------------------------------------------------------------------- Note (1): I-band photometry is from DENIS where available, or from SuperCOSMOS. Note (2): R-band uncertainties ~0.3mag (Hambly, Irwin & MacGillivray, 2001MNRAS.326.1295H). Note (3): Distances are parallaxes where available, or are estimated using an MJ-(J-K) relation from our best-fitting line on the MJ versus J-K CMD with some additional allowance for age uncertainty (see Section 3.4). Note (4): Notes as follows: d = Costa et al. (2005AJ....130..337C) e = Costa et al. (2006AJ....132.1234C) f = Tinney (1996MNRAS.281..644T) g = SpT in literature: Tinney (1998MNRAS.296L..42T), Kirkpatrick et al. (2000AJ....120..447K), Burgasser et al. (2002, Cat. J/ApJ/564/421), Cruz & Reid (2002, Cat. J/AJ/123/2828), Gizis (2002ApJ...575..484G), Cruz et al. (2003, Cat. J/AJ/126/2421), Lodieu et al. (2005, Cat. J/A+A/440/1061), Siegler et al. (2005ApJ...621.1023S), Burgasser & McElwain (2006AJ....131.1007B), Basri & Reiners (2006, Cat. J/AJ/132/663) and Phan-Bao & Bessel (2006, Cat. J/A+A/446/515) Note (5): Spectral types are from the literature where available, or have been determined from MJ versus spectral type relations from Dahn et al. (2002AJ....124.1170D) for I-J>= 2.8 and Leggett (1992) for I-J<2.8. Note (6): The potential moving group membership for each candidate as follows: CA = Castor IC = IC2391 PL = Pleiades HY = Hyades SI = Sirius -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 24-Jul-2015