J/AJ/142/77 New T dwarfs identified in Pan-STARRS 1 (Deacon+, 2011)
Four new T dwarfs identified in Pan-STARRS 1 commissioning data.
Deacon N.R., Liu M.C., Magnier E.A., Bowler B.P., Goldman B.,
Redstone J.A., Burgett W.S., Chambers K.C., Flewelling H., Kaiser N.,
Lupton R.H., Morgan J.S., Price P.A., Sweeney W.E., Tonry J.L.,
Wainscoat R.J., Waters C.
<Astron. J., 142, 77 (2011)>
=2011AJ....142...77D 2011AJ....142...77D
ADC_Keywords: Surveys ; Stars, dwarfs ; Infrared sources ; Photometry, infrared
Keywords: brown dwarfs - stars: low-mass - surveys
Abstract:
A complete well-defined sample of ultracool dwarfs is one of the key
science programs of the Pan-STARRS 1 optical survey telescope (PS1).
Here we combine PS1 commissioning data with the Two Micron All Sky
Survey (2MASS) to conduct a proper motion search (0.1-2.0"/yr) for
nearby T dwarfs, using optical+near-IR colors to select objects for
spectroscopic follow-up. The addition of sensitive far-red optical
imaging from PS1 enables discovery of nearby ultracool dwarfs that
cannot be identified from 2MASS data alone. We have searched
3700deg2 of PS1 y-band (0.95-1.03um) data to y∼19.5mag (AB) and
J∼16.5mag (Vega) and discovered four previously unknown bright T
dwarfs. Three of the objects (with spectral types T1.5, T2, and T3.5)
have photometric distances within 25pc and were missed by previous
2MASS searches due to more restrictive color selection criteria. The
fourth object (spectral type T4.5) is more distant than 25pc and is
only a single-band detection in 2MASS. We also examine the potential
for completing the census of nearby ultracool objects with the PS1
3{PI} survey.
Description:
We obtained follow-up imaging of candidates using WFCAM on the UKIRT.
Over the course of three and a half nights, a total of 195 candidates
were imaged in Y, J, H, and K on the 2010 June 16-19 (Hubble Space
Telescope,HST).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 91 194 Objects with discrepant photometry between
2MASS and UKIRT/UKIDSS
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/310 : UKIDSS-DR7 Large Area Survey (Lawrence+ 2011)
II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh 2MASS Hour of Right Ascension (J2000) (1)
4- 5 I2 min RAm 2MASS Minute of Right Ascension (J2000) (1)
7- 11 F5.2 s RAs 2MASS Second of Right Ascension (J2000) (1)
13 A1 --- DE- 2MASS sign of the Declination (J2000) (1)
14- 15 I2 deg DEd 2MASS Degree of Declination (J2000) (1)
17- 18 I2 arcmin DEm 2MASS Arcminute of Declination (J2000) (1)
20- 23 F4.1 arcsec DEs 2MASS Arcsecond of Declination (J2000) (1)
25- 29 F5.2 mag J2mag 2MASS J band magnitude (2)
31- 34 F4.2 mag e_J2mag The 1σ uncertainty in J2mag
36- 37 I2 h RAPh PS1 Hour of Right Ascension (J2000) (1)
39- 40 I2 min RAPm PS1 Minute of Right Ascension (J2000) (1)
42- 46 F5.2 s RAPs PS1 Second of Right Ascension (J2000) (1)
48 A1 --- DEP- PS1 Sign of the Declination (J2000) (1)
49- 50 I2 deg DEPd PS1 Degree of Declination (J2000) (1)
52- 53 I2 arcmin DEPm PS1 Arcminute of Declination (J2000) (1)
55- 58 F4.1 arcsec DEPs PS1 Arcsecond of Declination (J2000) (1)
60- 64 F5.2 mag ymag PS1 y-band (0.95-1.03µm) magnitude
66- 69 F4.2 mag e_ymag The 1σ uncertainty in ymag
71- 75 F5.2 mag Ymag MKO (Maunea Kea) Y band magnitude
77- 80 F4.2 mag e_Ymag The 1σ uncertainty in Ymag
82- 86 F5.2 mag Jmag MKO (Maunea Kea) J band magnitude (2)
88- 91 F4.2 mag e_Jmag The 1σ uncertainty in JMmag
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Note (1): "PS1" is Pan-STARRS 1 optical survey telescope.
Some of these pairings may be spurious. Hence no physical association
between the 2MASS and Pan-STARRS positions should be implied by an
object's inclusion in this table.
Note (2): For these purposes we define discrepant as objects whose J band
photometry differs by more than 0.6 magnitudes between the two
measurements.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 03-Nov-2012