Two T dwarfs from the UKIDSS Early Data Release

Details Two T dwarfs from the UKIDSS Early Data Release Two T dwarfs from the UKIDSS Early Data Release

2007-02-20

arxiv.org/abs/astro-ph/0702534v1

Astronomy and Astrophysics

Astrophysics

7 pages, 5 figures, A&A in press

Scientific paper

10.1051/0004-6361:20066403

We report on the first ultracool dwarf discoveries from the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey Early Data Release (LAS EDR), in particular the discovery of T dwarfs which are fainter and more distant than those found using the 2MASS and SDSS surveys. We aim to show that our methodologies for searching the ~27 sq degs of the LAS EDR are successful for finding both L and T dwarfs $via$ cross-correlation with the Sloan Digital Sky Survey (SDSS) DR4 release. While the area searched so far is small, the numbers of objects found shows great promise for near-future releases of the LAS and great potential for finding large numbers of such dwarfs. Ultracool dwarfs are selected by combinations of their YJH(K) UKIDSS colours and SDSS DR4 z-J and i-z colours, or, lower limits on these red optical/infrared colours in the case of DR4 dropouts. After passing visual inspection tests, candidates have been followed up by methane imaging and spectroscopy at 4m and 8m-class facilities. Our main result is the discovery following CH4 imaging and spectroscopy of a T4.5 dwarf, ULASJ 1452+0655, lying ~80pc distant. A further T dwarf candidate, ULASJ 1301+0023, has very similar CH4 colours but has not yet been confirmed spectroscopically. We also report on the identification of a brighter L0 dwarf, and on the selection of a list of LAS objects designed to probe for T-like dwarfs to the survey J-band limit. Our findings indicate that the combination of the UKIDSS LAS and SDSS surveys provide an excellent tool for identifying L and T dwarfs down to much fainter limits than previously possible. Our discovery of one confirmed and one probable T dwarf in the EDR is consistent with expectations from the previously measured T dwarf density on the sky.

Affiliated with

Also associated with

No associations

Rating

Two T dwarfs from the UKIDSS Early Data Release does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Two T dwarfs from the UKIDSS Early Data Release, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two T dwarfs from the UKIDSS Early Data Release will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-383047