J/AJ/154/134 Planetary-mass brown dwarfs in the Taurus SFR (Esplin+, 2017)
A survey for planetary-mass brown dwarfs in the Taurus and Perseus
star-forming regions.
Esplin T.L., Luhman K.L.
<Astron. J., 154, 134 (2017)>
=2017AJ....154..134E 2017AJ....154..134E (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Stars, brown dwarf ; Proper motions ;
Spectral types ; Extinction ; Photometry, infrared
Keywords: brown dwarfs - protoplanetary disks - stars: formation -
stars: low-mass
Abstract:
We present the initial results from a survey for planetary-mass brown
dwarfs in the Taurus star-forming region. We have identified brown
dwarf candidates in Taurus using proper motions and photometry from
several ground- and space- based facilities. Through spectroscopy of
some of the more promising candidates, we have found 18 new members of
Taurus. They have spectral types ranging from mid-M to early-L, and
they include the four faintest known members in extinction-corrected Ks,
which should have masses as low as ∼4-5 MJup according to evolutionary
models. Two of the coolest new members (M9.25, M9.5) have mid-IR excesses
that indicate the presence of disks. Two fainter objects with types of
M9-L2 and M9-L3 also have red mid-IR colors relative to photospheres
at =<L0, but since the photospheric colors are poorly defined at >L0,
it is unclear whether they have excesses from disks. We also have
obtained spectra of candidate members of the IC 348 and NGC 1333
clusters in Perseus that were identified by Luhman et al. Eight
candidates are found to be probable members, three of which are among
the faintest and least-massive known members of the clusters (∼5 MJup).
Description:
We have begun a new search for brown dwarfs in Taurus that improves
upon previous surveys of the region in terms of both coverage and depth.
This work is based on photometry and astrometry from wide-field images
collected by the Two Micron All Sky Survey (2MASS, Skrutskie et al.
2006, Cat. VII/233), the Spitzer Space Telescope (Werner et al.
2004ApJS..154....1W 2004ApJS..154....1W), the United Kingdom Infrared Telescope Infrared
Deep Sky Survey (UKIDSS, Lawrence et al. 2007, Cat. II/314), Pan-STARRS1
(PS1; Kaiser et al. 2002SPIE.4836..154K 2002SPIE.4836..154K, 2010SPIE.7733E..0EK), the
Sloan Digital Sky Survey (SDSS, York et al. 2000AJ....120.1579Y 2000AJ....120.1579Y;
Finkbeiner et al. 2004AJ....128.2577F 2004AJ....128.2577F), Gaia (Perryman et al.
2001A&A...369..339P 2001A&A...369..339P), and the Wide-field Infrared Survey Explorer
(WISE, Wright et al. 2010AJ....140.1868W 2010AJ....140.1868W).
We obtained near-IR spectra of 25 candidates with SpeX (Rayner et al.
2003PASP..115..362R 2003PASP..115..362R) at the NASA Infrared Telescope Facility (IRTF).
The instrument was operated in the prism mode with the 0.8" slit
(0.7-2.5 µm, R=150). We also observed nine additional candidates
with the Gemini Near-Infrared Spectrograph (GNIRS; Elias et al.
2006SPIE.6269E..4CE) in the cross-dispersed mode with the 31.7 l/mm
grating and the 0.67" slit (0.8-2.5 µm, R=800).
Objects:
--------------------------------------------------------
RA (ICRS) DE Designation(s)
--------------------------------------------------------
03 44 34 +32 09.8 IC 348 = Cl Collinder 41
03 28 55 +31 22.2 NGC 1333 = Ced 16
--------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 127 427 Proper Motions of Taurus Members
table2.dat 33 235 IRAC Observations of Taurus
table3.dat 83 34 Spectral Types for Candidate Members of Taurus
table4.dat 146 24 Mid-IR Photometry for Members of Taurus Adopted
Since Esplin et al. (2014, J/ApJ/784/126)
table5.dat 81 9 Spectral Types for Candidate Members of IC 348
and NGC 1333
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/328 : AllWISE Data Release (Cutri+ 2013)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/ApJ/525/466 : Young low-mass stars and brown dwarfs in IC 348
(Luhman+, 1999)
J/ApJ/578/914 : Low-mass stars in Taurus (Hartmann, 2002)
J/ApJ/597/555 : IR photometry of IC 348 young brown dwarfs (Mainzer+, 2003)
J/AJ/127/1131 : NGC 1333 low-mass stars infrared photometry (Wilking+, 2004)
J/A+A/446/485 : New very low-mass members in Taurus (Guieu+, 2006)
J/ApJ/645/676 : Spatial distribution of brown dwarfs in Taurus (Luhman+, 2006)
J/ApJ/647/1180 : Infrared photometry of Taurus SFR (Luhman+, 2006)
J/AJ/136/1372 : Very low-mass YSOs in NGC 1333 (Oasa+, 2008)
J/ApJS/186/111 : Spitzer observations of Taurus members (Luhman+, 2010)
J/ApJS/186/259 : Taurus Spitzer survey: new candidate members (Rebull+, 2010)
J/ApJ/784/126 : Infrared photometry of all known members in Taurus
(Esplin+, 2014)
J/AJ/153/46 : Spectroscopy of candidate members in Taurus (Luhman+, 2017)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Source name (G1)
26- 48 A23 --- OName ? Other name
50- 53 F4.1 mas/yr pmRA-IRAC [-2.8/16.3]? IRAC relative proper motion
in RA
55- 57 F3.1 mas/yr e_pmRA-IRAC [0/9.5]? Error in pmRA-IRAC
59- 63 F5.1 mas/yr pmDE-IRAC [-25.3/-0.1]? IRAC relative proper motion
in DE
65- 67 F3.1 mas/yr e_pmDE-IRAC [0.1/8.4]? Error in pmDE-IRAC
69- 73 F5.1 mas/yr pmRA-UKIDSS [-10.7/11.8]? UKIDSS relative proper motion
in RA
75- 77 F3.1 mas/yr e_pmRA-UKIDSS [2.8/7.5]? Error in pmRA-UKIDSS
79- 83 F5.1 mas/yr pmDE-UKIDSS [-28.8/-10]? UKIDSS relative proper motion
in DE
85- 87 F3.1 mas/yr e_pmDE-UKIDSS [2.8/7.5]? Error in pmDE-UKIDSS
89- 92 F4.1 mas/yr pmRA-2MGaia [-7.4/28.5]? 2MASS/Gaia proper motion
in RA
94- 96 F3.1 mas/yr e_pmRA-2MGaia [3.5/8.1]? Error in pmRA-2MGaia
98-102 F5.1 mas/yr pmDE-2MGaia [-42/-2.6]? 2MASS/Gaia proper motion
in DE
104-106 F3.1 mas/yr e_pmDE-2MGaia [3.5/9.4]? Error in pmDE-2MGaia
108-112 F5.1 mas/yr pmRA-2MPS1 [-14/29.6]? 2MASS/PS1 proper motion
in RA
114-116 F3.1 mas/yr e_pmRA-2MPS1 [3.8/8.6]? Error in pmRA-2MPS1
118-122 F5.1 mas/yr pmDE-2MPS1 [-40.3/-2.9]? 2MASS/PS1 proper motion
in DE
124-127 F4.1 mas/yr e_pmDE-2MPS1 [3.9/10.0]? Error in pmDE-2MPS1
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- AOR [3653120/47147008] Astronomical Observing Request
identifier
10- 14 I5 --- PID [6/90071] Program identifier
16- 26 A11 --- PI Principle Investigator name
28- 33 F6.1 yr Epoch [2004.2/2013.9] Year of observation
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Source name (G1)
26 I1 --- Memb [1/2] Membership flag (1=Member, 2=Non-member)
28- 38 A11 --- SpType Spectral type, or range and comment (G2)
40- 43 F4.2 mag b_AJmag [0/8.7]? J passband extinction, lower value
45- 47 F3.1 mag B_AJmag [1.2/1.5]? J passband extinction, upper value
49- 53 A5 --- Inst Instrument used (SpeX, GNIRS)
55- 65 A11 "date" Date Date of spectroscopy
67- 71 F5.2 mag Ksmag [10.39/15.88] Ks band magnitude
73- 76 F4.2 mag e_Ksmag [0.01/0.06] Uncertainty in Ksmag
78- 83 A6 --- r_Ksmag Catalog reference for Ksmag (UKIDSS, 2MASS)
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Source name (G1)
26- 30 F5.2 mag W1mag [6.73/15.06]? WISE W1 band magnitude
32- 35 F4.2 mag e_W1mag [0.02/0.04]? Uncertainty in W1mag
37 A1 --- n_W1mag [n] Note on W1mag (1)
39- 43 F5.2 mag W2mag [7.3/14.63]? WISE W2 band magnitude
45- 48 F4.2 mag e_W2mag [0.02/0.08]? Uncertainty in W2mag
50 A1 --- n_W2mag [n] Note on W2mag (1)
52 A1 --- l_W3mag [>] Limit flag on W3mag
54- 58 F5.2 mag W3mag [7.22/12.53]? WISE W3 band magnitude
60- 63 F4.2 mag e_W3mag [0.02/0.52]? Uncertainty in W3mag
65 A1 --- n_W3mag [an] Note on W3mag (1)
67 A1 --- l_W4mag [>] Limit flag on W4mag
69- 72 F4.2 mag W4mag [5.77/8.94]? WISE W4 band magnitude
74- 77 F4.2 mag e_W4mag [0.05/0.52]? Uncertainty in W4mag
79 A1 --- n_W4mag [an] Note on W4mag (1)
81- 85 F5.2 mag 3.6mag [7.45/14.85]? Spitzer/IRAC 3.6µm band
magnitude
87- 90 F4.2 mag e_3.6mag [0.02/0.03]? Uncertainty in 3.6mag
92 A1 --- n_3.6mag [o] Note on 3.6mag (1)
94- 98 F5.2 mag 4.5mag [7.39/14.57]? Spitzer/IRAC 4.5µm band
magnitude
100-103 F4.2 mag e_4.5mag [0.02/0.09]? Uncertainty in 4.5mag
105 A1 --- n_4.5mag [o] Note on 4.5mag (1)
107-111 F5.2 mag 5.8mag [7.38/14.4]? Spitzer/IRAC 5.8µm band
magnitude
113-116 F4.2 mag e_5.8mag [0.03/0.1]? Uncertainty in 5.8mag
118 A1 --- n_5.8mag [o] Note on 5.8mag (1)
120-124 F5.2 mag 8.0mag [7.35/14.08]? Spitzer/IRAC 8.0µm band
magnitude
126-129 F4.2 mag e_8.0mag [0.03/0.13]? Uncertainty in 8.0mag
131 A1 --- n_8.0mag [no] Note on 8.0mag (1)
133-136 F4.2 mag 24mag [7.24/9.16]? Spitzer/MIPS 24µm band magnitude
138-141 F4.2 mag e_24mag [0.04/0.31]? Uncertainty in 24mag
143 A1 --- n_24mag [no] Note on 24mag (1)
145-146 A2 --- Excess [Y N Y?] Mid-IR excess emission?
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Note (1): Note on individual photometry as follows:
a = Detection is false or unreliable based on visual inspection;
n = Non-detection;
o = Position outside of the camera's field of view.
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Source name (G1)
25 I1 --- Cluster [1/2] Cluster name (1=IC 348, 2=NGC 1333)
27- 45 A19 --- OName Other name(s)
47- 52 A6 --- SpType Spectral type, or range and comment (G2)
54- 56 F3.1 mag b_AJmag [0/5.4]? J passband extinction, lower value
58- 60 F3.1 mag B_AJmag [1.3/1.7]? J passband extinction, upper value
62- 63 A2 --- Memb [Y N? Y?] Member status
65- 69 A5 --- Inst Instrument used (SpeX, GNIRS)
71- 81 A11 "date" Date Date of spectroscopy
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Global notes:
Note (G1): Coordinate-based identifications from the 2MASS Point Source Catalog
(Cat. II/246) when available. Otherwise, identifications are from
the UKIDSS DR10 Catalog or ALLWISE Source Catalog (Cat. II/328).
Note (G2): Uncertainties are ±0.5 subclass unless indicated otherwise.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 12-Jun-2018