J/AJ/134/1162 11 new T dwarfs in 2MASS (Looper+, 2007)
Discovery of 11 new T dwarfs in the Two Micron All Sky Survey, including
a possible L/T transition binary.
Looper D.L., Kirkpatrick J.D., Burgasser A.J.
<Astron. J., 134, 1162-1182 (2007)>
=2007AJ....134.1162L 2007AJ....134.1162L
ADC_Keywords: Stars, pre-main sequence ; Photometry, infrared
Keywords: stars: low-mass, brown dwarfs - techniques: spectroscopic
Abstract:
We present the discovery of 11 new T dwarfs, found during the course
of a photometric survey for mid-to-late T dwarfs in the 2MASS Point
Source Catalog and from a proper-motion-selected sample of ultracool
dwarfs in the 2MASS Working Database. Using the NASA Infrared
Telescope Facility SpeX spectrograph, we obtained low-resolution
(R∼150) spectroscopy, allowing us to derive near-infrared spectral
types of T2-T8. We also present improved signal-to-noise ratio SpeX
low-resolution spectroscopy of the near-infrared T0 standard SDSS
J120747.17+024424.8 and T1 standard SDSSp J083717.22-000018.3. One of
these new T dwarfs, 2MASS J13243559+6358284, was also discovered
independently by Metchev et al.
Description:
We have carried out a proper-motion survey for ultracool dwarfs using
∼4700deg2 of multiepoch data in the 2MASS Working Database. We
conducted follow-up imaging to cull the large number of transients
from our 2MASS photometric search sample, using the UH 2.2m ULBCAM and
the IRTF 3.0m SpeX cameras. We imaged candidates with ULBCAM on 2006
February 9-12 and 16 UT and July 24 UT. We used SpeX camera to image
candidates during 2006 May 31 UT, August 17-18 UT, September 1-2 UT,
November 17 UT, and December 8-9 and 20-21 UT. We obtained
spectroscopic observations for a total of 20 science targets, 2 T
dwarf standards, and 20 calibrator A0 V stars between 2006 April 8 UT
and December 21 UT.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 73 50 Transients
table4.dat 113 16 Spectrophotometric properties of new and
confirmed T dwarfs
table9.dat 120 72 T Dwarfs in the Solar Neighborhood (within 25pc)
refs.dat 62 33 References
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See also:
J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002)
J/ApJ/564/421 : Spectra of T dwarfs. I. (Burgasser+, 2002)
J/AJ/126/2487 : T dwarfs in the southern hemisphere (Burgasser+, 2003)
J/AJ/126/3007 : Spectroscopy of faint red NLTT dwarfs (Reid+, 2003)
J/AJ/127/3553 : JHK photometry & spectroscopy for L & T dwarfs (Knapp+ 2004)
J/AJ/131/2722 : New L and T dwarfs from the SDSS (Chiu+, 2006)
J/ApJ/637/1067 : T dwarfs near-IR spectral classification (Burgasser+, 2006)
J/ApJ/648/629 : Radio observations of late M, L and T dwarfs (Berger+, 2006)
J/ApJ/651/502 : Spitzer IRAC photometry of M, L and T dwarfs (Patten+, 2006)
J/MNRAS/384/1399 : Proper motions of field L and T dwarfs (Jameson+, 2008)
J/MNRAS/390/1517 : Proper motions of field L and T dwarfs (Casewell+, 2008)
J/A+A/501/1059 : Infrared spectra of 9 T dwarfs (del Burgo+, 2009)
J/A+A/503/639 : NIR spectral of M-T dwarfs (Testi, 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
25- 29 F5.2 mag Jmag 2MASS J magnitude
31- 34 F4.2 mag e_Jmag rms uncertainty on Jmag
36- 40 F5.2 mag Hmag 2MASS H magnitude
42- 45 F4.2 mag e_Hmag rms uncertainty on Hmag
47- 51 F5.2 mag Ksmag 2MASS Ks magnitude
53- 56 F4.2 mag e_Ksmag ? rms uncertainty on Ksmag
58- 67 A10 "YYYY/MM/DD" Obs.Date UT date of 2MASS observation
69- 73 F5.1 deg beta Eliptic latitude
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1 A1 --- f_Name [NR] N=New T Dwarfs, R=Recovered T Dwarfs
3- 27 A25 --- Name 2MASS or SDSS name
28 A1 --- r_Name [d] Reference of recovered T dwarf (1)
30- 34 F5.2 mag Jmag 2MASS J magnitude
36- 39 F4.2 mag e_Jmag rms uncertainty on Jmag
41- 45 F5.2 mag J-H 2MASS J-H colour index
47- 50 F4.2 mag e_J-H rms uncertainty on J-H
52 A1 --- l_H-Ks Limit flag on H-Ks
53- 57 F5.2 mag H-Ks 2MASS H-Ks colour index
59- 62 F4.2 mag e_H-Ks ? rms uncertainty o n H-Ks
64 A1 --- l_J-Ks Limit flag on J-Ks
65- 69 F5.2 mag J-Ks 2MASS J-Ks colour index
71- 74 F4.2 mag e_J-Ks ? rms uncertainty on J-Ks
76- 80 F5.2 mag imag ? SDSS i magnitude
82- 85 F4.2 mag e_imag ? rms uncertainty on imag
87- 91 F5.2 mag zmag ? SDSS z magnitude
93- 96 F4.2 mag e_zmag ? rms uncertainty on zmag
98-103 A6 --- SpT Spectral type
104 A1 --- n_SpT [e] Note on SpT (2)
106-109 F4.1 pc Dist Spectrophotometric distance estimate
111-113 F3.1 pc e_Dist rms uncertainty on Dist
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Note (1): References for recovered T Dwarfs:
* 2MASS 0939-24 (Tinney et al., 2005AJ....130.2326T 2005AJ....130.2326T)
* SDSS 1346-00 (Tsvetanov et al., 2000ApJ...531L..61T 2000ApJ...531L..61T)
* SDSS 1630+08 (Chiu et al., 2006AJ....131.2722C 2006AJ....131.2722C)
* SDSS 1758+46 (Knapp et al., 2004, Cat. J/AJ/127/3553)
* SDSS 2124+01 (Knapp et al., 2004, Cat. J/AJ/127/3553)
Note (2): From Burgasser et al. (2006, Cat. J/ApJ/637/1067)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1 I1 --- d [1/2] Distance flag (1=d≤10pc, 2=10<d<25pc)
3- 29 A27 --- Name Name
31 A1 --- n_Name [*] * for new additions reported in this paper
32- 47 A16 --- OName Other name
49- 50 I2 --- Seq Discovery reference
52- 60 A9 --- SpT NIR spectral type
62- 67 F6.3 mag Jmag 2MASS J magnitude
69- 73 F5.2 mag Ksmag ? 2MASS Ks magnitude
74- 75 I2 --- r_Ksmag ? Origin of Ksmag (refs. 2 or 22)
77- 81 F5.2 pc DistJ ?=- Distance from J magnitude
83- 87 F5.2 pc DistPi ?=- Distance from parallax
89 A1 --- l_Dist Limit flag on Dist
90- 93 F4.1 pc Dist Adopted heliocentric distance (2)
95- 97 A3 --- Hres [Yes No] High-resolution imaging?
99-103 A5 -- Ref Reference, in refs.dat file
105-120 A16 --- Rem Remarks
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Note (2): Distance adopted from trigonometric parallax if measured.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 41 A18 --- Aut Author's name
43- 62 A20 --- Com Comments
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 03-Oct-2009