J/AJ/126/2487 T dwarfs in the southern hemisphere (Burgasser+, 2003)
The 2MASS wide-field T dwarf search.
II. Discovery of three T dwarfs in the southern hemisphere.
Burgasser A.J., Mcelwain M.W., Kirkpatrick J.D.
<Astron. J., 126, 2487-2494 (2003)>
=2003AJ....126.2487B 2003AJ....126.2487B
ADC_Keywords: Infrared sources ; Stars, dwarfs ; Photometry, infrared
Keywords: infrared radiation - solar neighborhood - stars: individual
(2MASS J03480772-6022270, 2MASS J05160945-0445499,
2MASS J22282889-4310262) - stars: low-mass, brown dwarfs
Abstract:
We present the discovery of three new southern hemisphere T dwarfs
identified in the Two Micron All Sky Survey (Cat. II/246). These
objects, 2MASS 0348-6022, 2MASS 0516-0445, and 2MASS 2228-4310, have
classifications T7, T5.5, and T6.5, respectively. Using linear
absolute magnitude/spectral type relations derived from T dwarfs with
measured parallaxes, we estimate spectrophotometric distances for
these discoveries; the closest, 2MASS 0348-6022, is likely within 10pc
of the Sun. Proper motions and estimated tangential velocities are
consistent with membership in the Galactic disk population. We also
list southern hemisphere T dwarf candidates that were either not found
in subsequent near-infrared imaging observations and are most likely
uncataloged minor planets, or have near-infrared spectra consistent
with background stars.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 98 50 T dwarf candidates absent in follow-up
OSIRIS images
table2.dat 108 35 Results of OSIRIS spectroscopic observations
--------------------------------------------------------------------------------
See also:
II/241 : 2MASS Catalog Intermediate Data Release (IPAC/UMass, 2000)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS designation
25- 27 I3 deg beta Ecliptic latitude
29- 38 A10 "YYYY/MM/DD" Date 2MASS observation date
40- 44 F5.2 mag Jmag 2MASS J magnitude (G1)
46- 49 F4.2 mag e_Jmag rms uncertainty on Jmag
51- 55 F5.2 mag J-H 2MASS J-H colour index (G1)
57- 60 F4.2 mag e_J-H rms uncertainty on J-H
62 A1 --- l_H-Ks Limit flag on H-Ks
63- 67 F5.2 mag H-Ks 2MASS H-Ks colour index (G1)
69- 72 F4.2 mag e_H-Ks ? rms uncertainty on H-Ks
74- 83 A10 --- Ident Identification (1)
85- 98 A14 --- Com Comment
--------------------------------------------------------------------------------
Note (1): Asteroid identifications are from the Small-Body Search tool
maintained by the Jet Propulsion Laboratory Solar System Dynamics
Group (http://ssd.jpl.nasa.gov/cgi-bin/sb_search)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 25 A25 --- Name Designation (2MASS or SDSS)
27- 31 F5.2 mag Jmag ? 2MASS J magnitude (G1)
33- 36 F4.2 mag e_Jmag ? rms uncertainty on Jmag
38- 42 F5.2 mag J-Ks ? 2MASS J-Ks colour index (G1)
44- 47 F4.2 mag e_J-Ks ? rms uncertainty on J-Ks
49- 58 A10 "YYYY/MM/DD" Date UT date
60- 63 I4 s Texp Exposition time
65- 68 F4.2 --- AirMass Air mass
70- 78 A9 --- Comp HD number of the calibrator
80- 85 A6 --- SpType Spectral type of the calibrator
88-107 A20 --- Type Type of the star
108 A1 --- n_Type [bc] Individual notes (1)
--------------------------------------------------------------------------------
Note (1): Individual notes as follows:
b = Candidate young brown dwarf in the Orion A complex (Strom et al.,
1993ApJ...412..233S 1993ApJ...412..233S; Carpenter, 2000AJ....120.3139C 2000AJ....120.3139C).
c = This object appeared much fainter at J band when imaged with
OSIRIS than as observed by 2MASS. It is possible that the 2MASS
source is a chance alignment with an uncataloged minor planet,
or that this source is intrinsically variable.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Photometry from the 2MASS EDR; note that some objects have
revised photometry placing them outside of our original WPSD search
constraints.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Burgasser et al., Paper I 2003AJ....125..850B 2003AJ....125..850B
(End) James Marcout, Patricia Bauer [CDS] 12-Jan-2004