J/ApJS/190/100 NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)
Discoveries from a near-infrared proper motion survey using multi-epoch
Two Micron All-Sky Survey data.
Kirkpatrick J.D., Looper D.L., Burgasser A.J., Schurr S.D., Cutri R.M.,
Cushing M.C., Cruz K.L., Sweet A.C., Knapp G.R., Barman T.S.,
Bochanski J.J., Roellig T.L., McLean I.S., McGovern M.R., Rice E.L.
<Astrophys. J. Suppl. Ser., 190, 100-146 (2010)>
=2010ApJS..190..100K 2010ApJS..190..100K
ADC_Keywords: Photometry, infrared ; Proper motions ; Stars, subdwarf ;
Spectral types
Keywords: brown dwarfs - infrared: stars - proper motions - solar neighborhood -
stars: late-type
Abstract:
We have conducted a 4030deg2 near-infrared proper motion survey using
multi-epoch data from the Two Micron All-Sky Survey (2MASS). We find
2778 proper motion candidates, 647 of which are not listed in SIMBAD.
After comparison to Digitized Sky Survey images, we find that 107 of
our proper motion candidates lack counterparts at B, R, and I bands
and are thus 2MASS-only detections. We present results of
spectroscopic follow-up of 188 targets that include the infrared-only
sources along with selected optical-counterpart sources with faint
reduced proper motions or interesting colors. We also establish a set
of near-infrared spectroscopic standards with which to anchor
near-infrared classifications for our objects. Among the discoveries
are six young field brown dwarfs, five "red L" dwarfs, three L-type
subdwarfs, twelve M-type subdwarfs, eight "blue L" dwarfs, and several
T dwarfs. We further refine the definitions of these exotic classes
to aid future identification of similar objects. We examine their
kinematics and find that both the "blue L" and "red L" dwarfs appear
to be drawn from a relatively old population.
Description:
Spectroscopic observations of 189 targets were obtained using eleven
different optical/near-infrared instruments at eight different
observatories. Details of this follow-up are given in Table 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 186 2791 List of 2MASS proper motion candidates
table2.dat 113 246 Spectroscopic follow-up of discoveries
table3.dat 111 28 Supporting observations of M and L dwarfs and
subdwarfs
table4.dat 79 20 New M and L dwarfs spectral standards in the
near-infrared
table5.dat 93 6 New low-gravity objects
table6.dat 93 5 New red L dwarfs
table7.dat 93 15 New M and L subdwarfs
table9.dat 93 8 New blue L dwarfs
table11.dat 93 5 New T dwarfs
table12.dat 93 5 Other interesting discoveries
table10.dat 109 20 Known blue L dwarfs
table13.dat 84 26 Measured velocities and distance estimates
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
J/A+A/497/619 : New ultra-cool dwarfs from SDSS and 2MASS (Zhang+, 2009)
J/MNRAS/394/857 : UKIDSS-2MASS proper motion survey (Deacon+, 2009)
J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)
J/AJ/131/2722 : New L and T dwarfs from the SDSS (Chiu+, 2006)
J/other/ARA+A/43.195 : L and T dwarf stars (Kirkpatrick, 2005)
J/AJ/127/3553 : JHK photometry and spectroscopy for L and T dwarfs (Knapp+,
2004)
J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)
J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS 2MASS Designation (1)
19 I1 --- L [1-3] List from which candidate was drawn (2)
21 A1 --- B [IJ] Shortest wavelength band at which
object is seen (3)
23 A1 --- S [*] Indicates spectroscopic follow-up
25- 28 F4.2 arcsec/yr 2Mpm ? 2MASS measured proper motion
30- 33 F4.2 arcsec/yr e_2Mpm ? Uncertainty in 2Mpm
35- 37 I3 deg 2MPA ? 2MASS measured proper motion position angle
39- 43 F5.2 --- MSig ? Motion significance
45- 50 F6.3 mag Jmag 2MASS J band magnitude
52- 56 F5.3 mag e_Jmag ? Uncertainty in Jmag
58- 63 F6.3 mag Hmag 2MASS H band magnitude
65- 69 F5.3 mag e_Hmag ? Uncertainty in Hmag
71- 76 F6.3 mag Ksmag ? 2MASS Ks band magnitude
78- 82 F5.3 mag e_Ksmag ? Uncertainty in Kmag
84- 88 F5.2 mag HJmag ? Reduced proper motion at J-band defined
as HJmag=Jmag+5*log(2Mpm)+5.
90- 94 F5.3 arcsec/yr USpm ? USNO-B measured proper motion
96-100 F5.3 arcsec/yr e_USpm ? Uncertainty in USpm
102-104 I3 deg USPA ? USNO-B proper motion position angle
106-110 F5.2 mag B1mag ? USNO-B B1 magnitude
112-116 F5.2 mag B2mag ? USNO-B B2 magnitude
118-122 F5.2 mag R1mag ? USNO-B R1 magnitude
124-128 F5.2 mag R2mag ? USNO-B R2 magnitude
130-134 F5.2 mag Imag ? USNO-B I magnitude
136-139 F4.2 arcsec/yr pm ? SIMBAD measured proper motion
141-144 F4.2 arcsec/yr e_pm ? Uncertainty in Spm
146-148 I3 deg pmPA ? position angle of Simbad proper motion
150-174 A25 --- SName SIMBAD name
176-186 A11 --- SpT ?=--- SIMBAD spectral type
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Note (1): The name includes the sexagesimal J2000 position encoded
as HHMMSS.ss+DDMMSS.s.
Note (2): List from which the proper motion candidate came; as follows:
1 = Section 2.1: data from the 2MASS All-Sky Point Source Catalog (PSC)
as epoch 1 (1X) and from the 2MASS 6X Point Source Working
Database/Catalog as epoch 2.,
2 = Section 2.2.1: 2MASS 1X survey only,
3 = Section 2.2.2: kinematic selection with imposed color criteria
between the first and last 2MASS epochs.
Note (3): For objects not visible on the B- or R-band plates of the
Digitized Sky Surveys. "I" if it visible in the DSS I-band plates or
"J" if it is seen only in 2MASS.
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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- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
24 A1 --- m_2MASS [AB] Component letter
25 A1 --- n_2MASS [bdgfh] Individual notes (1)
27- 38 A12 --- Tel Telescope
40- 46 A7 --- Inst Instrument
48- 57 A10 "Y/M/D" ObsDate Date(s) of observation (UT)
58- 60 A3 --- Obs2 Second date
62- 72 A11 --- Weath Weather conditions
74- 77 I4 s Int ? Integration time
78 A1 --- u_Int [?] Uncertainty flag for Int
80- 92 A13 --- SpT.Opt ?=--- Optical spectral type
94-111 A18 --- SpT.NIR ?=--- NIR spectral type
113 A1 --- n_SpT.NIR [ace] Notes on NIR spectrum (2)
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Note (1): Flag as follows:
b = 2MASS J1043+1213: this discovery has since been independently confirmed
and published by Chiu et al. (2006, Cat. J/AJ/131/2722).
d = 2MASS J1924+5506: this shares common proper motion with an object 10.0"
distant and at PA=115°. This other object has a 960 sec IRTF-SpeX
spectrum from 2005/10/19 (UT) that shows it to be a white dwarf.
f = 2MASS J0115-7519: this object was found in both the 1X-6X and the 1X-1X
survey.
g = 2MASS J0100+1711: this object is also known as LHS 1174.
h = Additional spectroscopic data for 2MASS J1821+1414 and 2MASS J2148+4003
are presented in Looper et al., 2008ApJ...685.1183L 2008ApJ...685.1183L.
Note (2): Flag as follows:
a = The near-infrared classification here is based only on a NIRSPEC N3
spectrum covering 1.15-1.35um.
c = 2MASS J1520-4422AB: near-infrared spectra types are taken from
Burgasser et al. (2007ApJ...657..494B 2007ApJ...657..494B).
e = 2MASS J2148+4003: spectral type based on a NIRSPEC N1+N2 spectrum
covering 0.95-1.30um.
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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- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
25- 40 A16 --- OName Other name
42- 53 A12 --- Tel Telescope
55- 61 A7 --- Inst Instrument
63- 72 A10 "YYYY/MM/DD" ObsDate Date of observation (UT)
74- 78 A5 --- Weath ?=--- Weather conditions
80- 83 I4 s Int Integration time
85- 92 A8 --- SpT.Opt ?=--- Optical spectral type
94-100 A7 --- SpT.new ?=--- New optical spectral type (1)
101 A1 --- n_SpT.new [b] Note (2)
103-110 A8 --- SpT ?=--- Adopted spectral type
111 A1 --- n_SpT [c-f] Note on the adopted spectral type (3)
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Note (1): Typed on the subdwarf classification system of Lepine et al.
(2007ApJ...669.1235L 2007ApJ...669.1235L) using the spectra obtained here.
Note (2): b = Does not warrant a subdwarf classification on the new
Lepine et al. (2007ApJ...669.1235L 2007ApJ...669.1235L) system.
Note (3): Flag as follows:
c = Established as the esdM7.5 standard in Lepine et al. (2007ApJ...669.1235L 2007ApJ...669.1235L)
d = Established as the usdM7.5 standard in Lepine et al. (2007ApJ...669.1235L 2007ApJ...669.1235L)
e = Established as the sdM8 standard in Lepine et al. (2007ApJ...669.1235L 2007ApJ...669.1235L)
f = See Cushing & Vacca (2006AJ....131.1797C 2006AJ....131.1797C) for more information on the
classification and interpretation of LSR J1610-0040.
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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- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
25- 32 A8 --- OName Other name
34- 35 A2 --- SpTIR ?=--- Adopted NIR spectral type
37- 42 F6.3 mag Jmag 2MASS J-band magnitude
44- 48 F5.3 mag e_Jmag Jmag uncertainty
50- 54 F5.3 mag J-H 2MASS J-H color index
56- 60 F5.3 mag e_J-H J-H uncertainty
62- 66 F5.3 mag J-Ks 2MASS J-Ks color index
68- 72 F5.3 mag e_J-Ks J-Ks uncertainty
74- 77 A4 --- SpT.O ?=--- Published optical spectral type
79 I1 --- r_SpT.O ?=- Optical reference (1)
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Note (1): References as follows:
1 = Kirkpatrick et al., 2000AJ....120..447K 2000AJ....120..447K;
2 = Cruz et al., 2003, Cat. J/AJ/126/2421;
3 = Kirkpatrick et al., 1991ApJS...77..417K 1991ApJS...77..417K;
4 = Kirkpatrick et al., 1995AJ....109..797K 1995AJ....109..797K;
5 = Kirkpatrick et al., 1999ApJ...519..802K 1999ApJ...519..802K;
6 = Kirkpatrick et al., 2008ApJ...689.1295K 2008ApJ...689.1295K;
7 = Gizis et al., 2000AJ....120.1085G 2000AJ....120.1085G;
8 = unpublished from Kirkpatrick, as listed in DwarfArchives.org.
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Byte-by-byte Description of file: table[5679].dat table1[12].dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
24 A1 --- f_2MASS [ab] Flag on 2MASS (1)
26- 38 A13 --- SpT.Opt ?=--- Optical spectral type (2)
40- 57 A18 --- SpT.NIR ?=--- NIR spectral type
59- 63 F5.3 mag J-H 2MASS J-H color index
65- 69 F5.3 mag e_J-H J-H uncertainty
71- 75 F5.3 mag H-Ks 2MASS H-Ks color index
77- 81 F5.3 mag e_H-Ks H-Ks uncertainty
83- 87 F5.3 mag J-Ks 2MASS J-Ks color index
89- 93 F5.3 mag e_J-Ks J-Ks uncertainty
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Note (1): Flag as follows:
a = See Looper et al. (2008ApJ...685.1183L 2008ApJ...685.1183L) for in-depth discussion
b = Discovered independently by Chiu et al. (2006, Cat. J/AJ/131/2722).
Note (2): In table5, optical spectral types use the Greek suffix designations of
Cruz et al. (2009AJ....137.3345C 2009AJ....137.3345C) in which γ is used to denote low
gravity (as opposed to normal (α, usually dropped for convenience) or
intermediate (β) gravity). Objects of extremely low gravity are further
denoted by δ, as originally outlined in Kirkpatrick (2005,
Cat. J/other/ARA+A/43.195) and Kirkpatrick et al. (2006ApJ...639.1120K 2006ApJ...639.1120K).
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name Designation (SDSS JHHMMSS.ss+DDMMSS.s or
2MASS JHHMMSSss+DDMMSSs)
26 A1 --- f_Name [abc] Flag on name (1)
28- 29 I2 --- r_Name Discovery reference (2)
31- 34 F4.2 arcsec/yr Mpm Proper motion
36- 39 F4.2 arcsec/yr e_Mpm Mpm uncertainty
41- 44 F4.1 pc Dist Distance (3)
45 A1 --- u_Dist [:] Uncertainty flag for Dist
47- 50 F4.1 pc e_Dist ? Distance uncertainty
52- 54 I3 km/s Vtan Tangential velocity
55 A1 --- u_Vtan [:] Uncertainty flag for Vtan
57- 58 I2 km/s e_Vtan ? Vtan uncertainty
60- 61 I2 --- r_Vtan Kinematic reference (2)
63- 68 A6 -- SpT.Opt ?=--- Optical spectral type
70- 87 A18 --- SpT.NIR ?=--- NIR spectral type
89- 91 F3.1 --- e_SpT.NIR ? SpTypeIR uncertainty
93- 97 A5 --- r_SpT.NIR Spectral type reference(s) (2)
99-103 F5.3 mag J-Ks ? 2MASS J-Ks color index
105-109 F5.3 mag e_J-Ks ? J-Ks uncertainty
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Note (1): Flag as follows:
a = SDSS J0805+4812: suspected binary comprised of mid-L and mid-T
components; Burgasser et al. (2007ApJ...657..494B 2007ApJ...657..494B).
b = 2MASS J09211411-2104446: also known as SIPS J0921-2104.
c = 2MASS J1711+4028: also known as G 203-50B. Optical spectral type is
determined here for the first time using a spectrum acquired on
2009/10/11 (UT) at Keck-I with LRIS (1200s integration).
Note (2): References as follows:
1 = This paper;
2 = Knapp et al., 2004, Cat. J/AJ/127/3553;
3 = Cruz et al., 2003, Cat. J/AJ/126/2421;
4 = Folkes et al., 2007MNRAS.378..901F 2007MNRAS.378..901F;
5 = Chiu et al. 2006, Cat. J/AJ/131/2722;
6 = Deacon et al., 2005, Cat. J/A+A/435/363;
7 = Radigan et al., 2008ApJ...689..471R 2008ApJ...689..471R;
8 = Faherty et al., 2009AJ....137....1F 2009AJ....137....1F;
9 = Sheppard & Cushing, 2009AJ....137..304S 2009AJ....137..304S;
10 = Burgasser et al., 2008ApJ...672.1159B 2008ApJ...672.1159B;
11 = Reid et al., 2008, Cat. J/AJ/136/1290;
12 = Zhang et al., 2009, Cat. J/A+A/497/619;
13 = Gizis et al., 2000AJ....120.1085G 2000AJ....120.1085G;
14 = Hawley et al., 2002, Cat. J/AJ/123/3409.
Note (3): For the new discoveries, we estimate a distance using the 2MASS J-band
magnitude and the predicted absolute J-band magnitude given by the optical
spectral type, as given by the relation of Looper et al., 2008ApJ...685.1183L 2008ApJ...685.1183L.
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Byte-by-byte Description of file: table13.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- OType Type of object (1)
5- 9 A5 --- --- [2MASS]
11- 27 A17 --- 2MASS 2MASS designation (JHHMMSSss+DDMMSSs)
29- 35 A7 --- Source Optical or NIR (2)
37- 45 A9 --- SpType ?=--- Spectral type
47- 56 A10 "YYYY/MM/DD" ObsDate Observation date (UT)
58- 61 I4 km/s Vrad Radial velocity
63- 64 I2 km/s e_Vrad [50] Vrad uncertainty
66- 68 I3 pc Dist Estimated distance (3)
70- 72 I3 km/s Vtan Tangential velocity
74- 76 I3 km/s e_Vtan Vtan uncertainty
78- 80 I3 km/s Vel Total space motion
82- 84 I3 km/s e_Vel Vel uncertainty
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Note (1): Type as follows:
LgO = Low-gravity Objects
RLD = Red L Dwarfs
Lsd = Late-M and L Subdwarfs
BLD = Blue L Dwarfs
Note (2): Type of spectrum, as given in Table 2, from which the listed spectral
type and radial velocity were measured.
Note (3): See Sections 6.1 and 6.3 for an object-by-object discussion of the
distance estimates for the low-gravity objects and subdwarfs. Distances to the
red and blue L dwarfs have been estimated with the Looper et al.,
2008ApJ...685.1183L 2008ApJ...685.1183L, relations and use the listed spectral type and measured
2MASS J magnitude.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 30-Sep-2010