J/AJ/144/148 Infrared photometry of brown dwarf and Hyper-LIRG (Griffith+, 2012)
Spitzer photometry of WISE-selected brown dwarf and hyper-luminous infrared
galaxy candidates.
Griffith R.L., Kirkpatrick J.D., Eisenhardt P.R.M., Gelino C.R.,
Cushing M.C., Benford D., Blain A., Bridge C.R., Cohen M., Cutri R.M.,
Donoso E., Jarrett T.H., Lonsdale C., Mace G., Mainzer A., Marsh K.,
Padgett D., Petty S., Ressler M.E., Skrutskie M.F., Stanford S.A.,
Stern D., Tsai C.-W., Wright E.L., Wu J., Yan L.
<Astron. J., 144, 148 (2012)>
=2012AJ....144..148G 2012AJ....144..148G (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, infrared ; Spectral types ; Galaxies, IR ;
Stars, late-type
Keywords: brown dwarfs - galaxies: evolution - galaxies: high-redshift -
galaxies: photometry
Abstract:
We present Spitzer 3.6 and 4.5µm photometry and positions for a
sample of 1510 brown dwarf candidates identified by the Wide-field
Infrared Survey Explorer (WISE) all-sky survey. Of these, 166 have
been spectroscopically classified as objects with spectral types M(1),
L(7), T(146), and Y(12). Sixteen other objects are non-(sub)stellar in
nature. The remainder are most likely distant L and T dwarfs lacking
spectroscopic verification, other Y dwarf candidates still awaiting
follow-up, and assorted other objects whose Spitzer photometry reveals
them to be background sources. We present a catalog of Spitzer
photometry for all astrophysical sources identified in these fields
and use this catalog to identify seven fainter (4.5µm∼17.0mag)
brown dwarf candidates, which are possibly wide-field companions to
the original WISE sources. To test this hypothesis, we use a sample of
919 Spitzer observations around WISE-selected high-redshift
hyper-luminous infrared galaxy candidates. For this control sample, we
find another six brown dwarf candidates, suggesting that the seven
companion candidates are not physically associated. In fact, only one
of these seven Spitzer brown dwarf candidates has a photometric
distance estimate consistent with being a companion to the WISE brown
dwarf candidate. Other than this, there is no evidence for any widely
separated (>20AU) ultra-cool binaries. As an adjunct to this paper, we
make available a source catalog of ∼7.33x105 objects detected in all
of these Spitzer follow-up fields for use by the astronomical
community. The complete catalog includes the Spitzer 3.6 and 4.5µm
photometry, along with positionally matched B and R photometry from
USNO-B; J, H, and Ks photometry from Two Micron All-Sky Survey; and
W1, W2, W3, and W4 photometry from the WISE all-sky catalog.
Description:
Warm Spitzer observations were carried out at 3.6 and 4.5µm under
Spitzer programs 70062 and 80109 (Table1) and Spitzer programs 70162
and 80033 (Table2). IRAC has a 5'*5' field of view with 1.2" pixels.
The Astronomical Observation Requests (AORs) were executed between
2010 June and 2012 May. These observations have been described in
detail in Kirkpatrick et al. (2011, cat. J/ApJS/197/19) and Eisenhardt
et al. (2012ApJ...755..173E 2012ApJ...755..173E).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 148 1510 Brown dwarf photometric catalog
table2.dat 136 906 W1W2-dropout photometric catalog (hyper-luminous
infra-red galaxy candidates)
table3.dat 210 733373 Spitzer/WISE photometric catalog
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See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
J/ApJS/197/19 : First brown dwarfs discovered by WISE (Kirkpatrick+, 2011)
J/ApJ/716/530 : Mid-IR variability from the SDWFS (Kozlowski+, 2010)
J/ApJ/701/428 : The Spitzer Deep, Wide-Field Survey (SDWFS) (Ashby+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- WISEP WISE sexigesimal designation
<[GKE2012] JHHMMSS.ss+DDMMSS.s> in Simbad
20- 26 A7 --- SpT Near-IR spectral type
28- 37 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
39- 48 F10.6 deg DEdeg Declination in decimal degrees (J2000)
50- 55 F6.3 mag [3.6] Spitzer/IRAC 3.6µm Vega magnitude
57- 61 F5.3 mag e_[3.6] Uncertainty in [3.6]
63- 68 F6.3 mag [4.5] Spitzer/IRAC 4.5µm Vega magnitude
70- 74 F5.3 mag e_[4.5] Uncertainty in [4.5]
76- 81 F6.3 mag [3.4] WISE 3.4µm (W1) profile-fit magnitude
83- 87 F5.3 mag e_[3.4] ? Uncertainty in [3.4]
89- 92 F4.1 --- S/N1 WISE 3.4µm signal-to-noise ratio
94- 99 F6.3 mag [4.6] WISE 4.6µm (W2) profile-fit magnitude
101-105 F5.3 mag e_[4.6] ? Uncertainty in [4.6]
107-110 F4.1 --- S/N2 WISE 4.6µm signal-to-noise ratio
112-117 F6.3 mag [12] ? WISE 12.0µm (W3) profile-fit magnitude
119-123 F5.3 mag e_[12] ? Uncertainty in [12]
125-129 F5.1 --- S/N3 ? WISE 12.0µm signal-to-noise ratio
131-136 F6.3 mag [22] ? WISE 22.0µm (W4) profile-fit magnitude
138-142 F5.3 mag e_[22] ? Uncertainty in [22]
144-148 F5.1 --- S/N4 ? WISE 22.0µm signal-to-noise ratio
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- WISEP WISE sexigesimal designation
<[GKE2012] JHHMMSS.s+DDMMSS.s> in Simbad (1)
19- 28 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
30- 39 F10.6 deg DEdeg Declination in decimal degrees (J2000)
41- 46 F6.3 mag [3.6] ? Spitzer/IRAC 3.6µm Vega magnitude
48- 52 F5.3 mag e_[3.6] ? Uncertainty in [3.6]
54- 59 F6.3 mag [4.5] Spitzer/IRAC 4.5µm Vega magnitude
61- 65 F5.3 mag e_[4.5] Uncertainty in [4.5]
67- 72 F6.3 mag [3.4] ? WISE 3.4µm (W1) profile-fit magnitude
74- 78 F5.3 mag e_[3.4] ? Uncertainty in [3.4]
80- 83 F4.1 --- S/N1 ? WISE 3.4µm signal-to-noise ratio
85- 90 F6.3 mag [4.6] ? WISE 4.6µm (W2) profile-fit magnitude
92- 96 F5.3 mag e_[4.6] ? Uncertainty in [4.6]
98-101 F4.1 --- S/N2 ? WISE 4.6µm signal-to-noise ratio
103-108 F6.3 mag [12] ? WISE 12.0µm (W3) profile-fit magnitude
110-114 F5.3 mag e_[12] ? Uncertainty in [12]
116-119 F4.1 --- S/N3 ? WISE 12.0µm signal-to-noise ratio
121-125 F5.3 mag [22] ? WISE 22.0µm (W4) profile-fit magnitude
127-131 F5.3 mag e_[22] ? Uncertainty in [22]
133-136 F4.1 --- S/N4 ? WISE 22.0µm signal-to-noise ratio
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Note (1): Eisenhardt et al. (2012ApJ...755..173E 2012ApJ...755..173E) have identified a rare
population of objects termed "W1W2-dropout" galaxies (Hyper-Luminous
InfraRed Galaxy (HyLIRG) candidates), because they are faint or
undetected in WISE/W1 (3.4µm bandpass) and WISE/W2 (4.6µm) but
well detected in WISE/W3 (12µm or WISE/W4 (22µm).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1 A1 --- --- [r]
2- 9 I8 --- AOR Astronomical Observation Request
10 A1 --- --- [_]
12- 16 A5 --- n_AOR Origin of Spitzer follow-up (BD or EXGAL) (1)
18- 27 F10.6 deg RAdeg Right ascension in decimal degrees (J2000)
29- 38 F10.6 deg DEdeg Declination in decimal degrees (J2000)
40- 45 F6.3 mag [3.6] [3.7/99]? Spitzer/IRAC 3.6µm Vega magnitude
47- 54 F8.3 mag e_[3.6] [0/2190]? Uncertainty in [3.6]
56- 61 F6.3 mag [4.5] [3.8/99]? Spitzer/IRAC 4.5µm Vega magnitude
63- 68 F6.3 mag e_[4.5] [0/40.8]? Uncertainty in [4.5]
70- 72 F3.1 --- S/G1 [0/1] SExtractor Star/Galaxy separator measured
at 3.6µm (2)
74- 76 F3.1 --- S/G2 [0/1] SExtractor Star/Galaxy separator measured
at 4.5µm (2)
78- 79 I2 --- N1 Total number of Spitzer frames at source
position 3.6µm
81- 82 I2 --- N2 Total number of Spitzer frames at source
position 4.5µm
84- 89 F6.3 mag [3.4] ? WISE 3.4µm (W1) profile-fit magnitude
91- 95 F5.3 mag e_[3.4] ? Uncertainty in [3.4]
97-101 F5.1 --- S/N1 ? WISE 3.4µm signal-to-noise ratio
103-108 F6.3 mag [4.6] ? WISE 4.6µm (W2) profile-fit magnitude
110-114 F5.3 mag e_[4.6] ? Uncertainty in [4.6]
116-119 F4.1 --- S/N2 ? WISE 4.6µm signal-to-noise ratio
121-126 F6.3 mag [12] ? WISE 12.0µm (W3) profile-fit magnitude
128-132 F5.3 mag e_[12] ? Uncertainty in [12]
134-138 F5.1 --- S/N3 ? WISE 12.0µm signal-to-noise ratio
140-145 F6.3 mag [22] ? WISE 22.0µm (W4) profile-fit magnitude
147-151 F5.3 mag e_[22] ? Uncertainty in [22]
153-157 F5.1 --- S/N4 ? WISE 22.0µm signal-to-noise ratio
159-164 F6.3 mag Jmag ? 2MASS J magnitude
166-170 F5.3 mag e_Jmag ? Uncertainty in Jmag
172-177 F6.3 mag Hmag ? 2MASS H magnitude
179-183 F5.3 mag e_Hmag ? Uncertainty in Hmag
185-190 F6.3 mag Kmag ? 2MASS Ks magnitude
192-196 F5.3 mag e_Kmag ? Uncertainty in Kmag
198-203 F6.3 mag Bmag [6.32/50]? USNO-B B2 magnitude
205-210 F6.3 mag Rmag [6.04/50]? USNO-B R2 magnitude
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Note (1):
BD = From Spitzer program 70062 (see Table1);
EXGAL = From Spitzer programs 70162 and 80033 (see Table2).
Note (2): From 0=extended source to 1=point source.
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 24-Jan-2014