J/ApJ/710/1627 Mid-IR photometry of cold brown dwarfs (Leggett+, 2010)
Mid-infrared photometry of cold brown dwarfs: diversity in age, mass, and
metallicity.
Leggett S.K., Burningham B., Saumon D., Marley M.S., Warren S.J.,
Smart R.L., Jones H.R.A., Lucas P.W., Pinfield D.J., Tamura M.
<Astrophys. J., 710, 1627-1640 (2010)>
=2010ApJ...710.1627L 2010ApJ...710.1627L
ADC_Keywords: Photometry, infrared ; Stars, late-type ; Spectral types
Keywords: brown dwarfs - infrared: stars - stars: low-mass
Abstract:
We present new Spitzer Infrared Array Camera (IRAC) photometry of 12
very late-type T dwarfs: nine have [3.6], [4.5], [5.8], and [8.0]
photometry and three have [3.6] and [4.5] photometry only. Combining
this with previously published photometry, we investigate trends with
type and color that are useful for both the planning and
interpretation of infrared surveys designed to discover the coldest T
or Y dwarfs. The online appendix provides a collation of MKO-system
YJHKL'M' and IRAC photometry for a sample of M, L, and T dwarfs. There
are 12 dwarfs currently known with H-[4.5]>3.0, and
500K≲Teff≲800K, which we examine in detail. The ages of the dwarfs
in the sample range from very young (0.1-1.0Gyr) to relatively old
(3-12Gyr). The mass range is possibly as low as 5 Jupiter masses to up
to 70 Jupiter masses, i.e., near the hydrogen burning limit. The
metallicities also span a large range, from [m/H]=-0.3 to [m/H]=+0.3.
Description:
The Spitzer General Observer programs 40449 and 60093, and the
Director's Time program 527, allowed us to obtain IRAC photometry of
apparently very late-type T dwarfs discovered in the UKIDSS data, that
had an estimated brightness of [4.5]<16.5mag. All targets observed
were found in the Large Area Survey (LAS) component of the UKIDSS.
The UKIDSS photometric system is described in Hewett et al.
(2006MNRAS.367..454H 2006MNRAS.367..454H) and is based on the Mauna Kea Observatories
(MKO) system. We were awarded Spitzer Director's Time (program 527)
for photometry and spectroscopy of the T8.5 companion to an M dwarf,
ULAS J214638.83-301038.7, or Wolf 940B.
The archived data were obtained through GO programs 20544 and 40198,
and GT 35.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 212 225 Data compilation table
refs.dat 77 86 References
--------------------------------------------------------------------------------
See also:
II/310 : UKIDSS-DR7 Large Area Survey (Lawrence+ 2012)
J/ApJS/197/19 : First brown dwarfs discovered by WISE (Kirkpatrick+, 2011)
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)
J/ApJ/676/1281 : L and T dwarfs in 2MASS/SDSS (Metchev+, 2008)
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/AJ/134/1162 : 11 new T dwarfs in 2MASS (Looper+, 2007)
J/AJ/131/2722 : New L and T dwarfs from the SDSS (Chiu+, 2006)
J/ApJ/651/502 : Spitzer IRAC photometry of M, L, and T dwarfs (Patten+,
2006)
J/ApJ/637/1067 : Near-IR spectral classification of T dwarfs (Burgasser+,
2006)
J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)
J/AJ/127/2856 : Brown dwarfs in the 2MASS Survey (Burgasser+, 2004)
J/AJ/127/3553 : JHK photometry and spectroscopy for L and T dwarfs (Knapp+,
2004)
J/AJ/125/3302 : HST binary very low mass stars and brown dwarfs (Gizis+,
2003)
J/AJ/126/2487 : T dwarfs in the southern hemisphere (Burgasser+, 2003)
J/ApJ/564/421 : Spectra of T dwarfs. I. (Burgasser+, 2002)
J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002)
http://www.ukidss.org/ : UKIRT Infrared Deep Sky Survey home page
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- Name Source name
19- 28 F10.7 h RAhour Right ascension in decimal hours (J2000) (1)
30- 39 F10.6 deg DEdeg Declination in decimal degrees (J2000) (1)
41- 44 A4 --- SpT MK spectral type (2)
46- 50 F5.2 mag M-m ? Distance modulus (4)
52- 56 F5.2 mag JMag ? MKO absolute J-band magnitude
58- 62 F5.2 mag Ymag ? MKO Y-band Vega magnitude
64- 68 F5.2 mag Jmag MKO J-band Vega magnitude
70- 74 F5.2 mag Hmag MKO H-band Vega magnitude
76- 80 F5.2 mag Kmag MKO K-band Vega magnitude
82- 86 F5.2 mag L'mag ? MKO L'-band Vega magnitude
88- 92 F5.2 mag M'mag ? MKO M'-band Vega magnitude
94- 98 F5.2 mag [3.6] ? Spitzer/IRAC 3.6 micron band Vega magnitude (3)
100-104 F5.2 mag [4.5] ? Spitzer/IRAC 4.5 micron band Vega magnitude (3)
106-110 F5.2 mag [5.9] ? Spitzer/IRAC 5.9 micron band Vega magnitude (3)
112-116 F5.2 mag [8.0] ? Spitzer/IRAC 8.0 micron band Vega magnitude (3)
118-120 F3.1 --- e_SpT Uncertainty in SpType
122-125 F4.2 mag e_M-m ? Uncertainty in M-m
127-130 F4.2 mag e_Ymag ? Uncertainty in Ymag
132-135 F4.2 mag e_Jmag Uncertainty in Jmag
137-140 F4.2 mag e_Kmag Uncertainty in Kmag
142-145 F4.2 mag e_L'mag ? Uncertainty in L'mag
147-150 F4.2 mag e_M'mag ? Uncertainty in M'mag
152-155 F4.2 mag e_[3.6] ? Uncertainty in [3.6]
157-160 F4.2 mag e_[4.5] ? Uncertainty in [4.5]
162-165 F4.2 mag e_[5.9] ? Uncertainty in [5.9]
167-170 F4.2 mag e_[8.0] ? Uncertainty in [8.0]
172-176 A5 --- Ref Discovery reference number(s) (see refs.dat file)
178-179 I2 --- r_SpT Spectral type reference number (see refs.dat file)
181-188 A8 --- r_Plx Trigonometric parallax reference number(s) (see
refs.dat file)
190-191 I2 --- r_Ymag ? Y band reference number (see refs.dat file)
193-197 A5 --- r_JHK JHK magnitude reference number(s) (see refs.dat
file)
199-203 A5 --- r_LM L'M' magnitude reference number(s) (see refs.dat
file)
205-206 I2 --- r_IRAC ? IRAC photometry reference number (see refs.dat
file)
208-212 A5 --- r_mult Source multiplicity reference number(s) (see
refs.dat file)
--------------------------------------------------------------------------------
Note (1): Note that the epoch varies and the dwarfs can have high proper motion.
Note (2): For L and T dwarfs these are infrared types except for a few of the
L dwarfs, see references.
Note (3): Not corrected for spectral distribution.
Note (4): the value listed is the opposite of the classical distance modulus,
i.e. the distance r is given by log(r) = 1-(M-m)/5.
--------------------------------------------------------------------------------
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- 42 A19 --- Aut Author's name(s)
44- 77 A34 --- Comm Comment
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Mar-2012