J/MNRAS/418/1231 New brown dwarfs in upper Sco (Dawson+, 2011)
New brown dwarfs in the south part of the upper Scorpius association.
Dawson P., Scholz A., Ray T.P.
<Mon. Not. R. Astron. Soc., 418, 1231-1237 (2011)>
=2011MNRAS.418.1231D 2011MNRAS.418.1231D
ADC_Keywords: Clusters, open ; Stars, late-type ; Infrared sources ;
Photometry, infrared
Keywords: techniques: photometric -
open clusters and associations: individual: Upper Scorpius -
infrared: stars
Abstract:
This paper presents the results of a search for brown dwarfs in the
Upper Scorpius Association using data from the UKIRT Infrared Deep Sky
Survey (UKIDSS) Galactic Cluster Survey. Candidate young brown dwarfs
were first chosen by their position in colour magnitude diagrams with
further selection based on proper motions to ensure Upper Scorpius
membership. Proper motions were derived by comparing UKIDSS and Two
Micron All Sky Survey (2MASS) data. Using that method we identify 19
new brown dwarfs in the southern part of the association. In addition
there are up to eight likely members with slightly higher dispersion
velocity. The ratio of brown dwarfs to stars was found to be
consistent with other areas in Upper Scorpius. It was also found to be
similar to other results from young clusters with OB associations, and
lower than those without, suggesting the brown dwarf formation rate
may be a function of environment.
Description:
The United Kingdom Infra-Red Telescope (UKIRT) is currently conducting
the United Kingdom UKIDSS - the results of which are being made
available in a series of releases. This work used the 8th Data Release
(DR8Plus).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 95 6 Data for the 6 objects outside the range of Fig.4
table2.dat 95 28 *Data for the final objects selected
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Note on table2.dat: Also included are the eight other objects shown in Fig.3
and lastly, the object too faint to be recorded in 2MASS.
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name Name (2MASS JHHMMSSss+DDMMSSs or
UGCS JHHMMSS.ss+DDMMSS.s) (1)
26 A1 --- n_Name [*] Note (2)
27- 28 I2 h RAh UKIDSS Right ascension (J2000, epoch≃2007.3)
30- 31 I2 min RAm UKIDSS Right ascension (J2000, epoch≃2007.3)
33- 37 F5.2 s RAs UKIDSS Right ascension (J2000, epoch≃2007.3)
39 A1 --- DE- UKIDSS Declination sing (J2000, epoch≃2007.3)
40- 41 I2 deg DEd UKIDSS Declination (J2000, epoch≃2007.3)
43- 44 I2 arcmin DEm UKIDSS Declination (J2000, epoch≃2007.3)
46- 49 F4.1 arcsec DEs UKIDSS Declination (J2000, epoch≃2007.3)
51- 55 F5.2 mag Zmag UKIDSS Z magnitude
57- 61 F5.2 mag Ymag UKIDSS Y magnitude
63- 67 F5.2 mag Jmag UKIDSS J magnitude
69- 73 F5.2 mag Hmag UKIDSS H magnitude
75- 79 F5.2 mag Kmag UKIDSS K magnitude
81- 87 F7.2 mas/yr pmRA ? Proper motion along RA (*cos(DE))
89- 95 F7.2 mas/yr pmDE ? Proper motion along DE
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Note (1): the published table use "2MASSJ" and "UGCSJ" designations;
the 'J' is here attached to the position to conform to IAU
nomenclature recommendations.
Note (2): In table1, 2MASS J16035915-2806086 (contraction of
2MASS J16035915-2806104 and 2MASS J16035875-2806086) was a typo, corrected
into 2MASS J16035875-2806086 by CDS.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Jun-2012