SIMBAD references

2008ApJ...676.1281M - Astrophys. J., 676, 1281-1306 (2008/April-1)

A cross-match of 2MASS and SDSS: newly found L and T dwarfs and an estimate of the space density of T dwarfs.


Abstract (from CDS):

We report new L and T dwarfs found in a cross-match of the SDSS Data Release 1 and 2MASS. Our simultaneous search of the two databases effectively allows us to relax the criteria for object detection in either survey and to explore the combined databases to a greater completeness level. We find two new T dwarfs in addition to the 13 already known in the SDSS DR1 footprint. We also identify 22 new candidate and bona fide L dwarfs, including a new young L2 dwarf and a peculiar potentially metal-poor L2 dwarf with unusually blue near-IR colors. These discoveries underscore the utility of simultaneous database cross-correlation in searching for rare objects. Our cross-match completes the census of T dwarfs within the joint SDSS and 2MASS flux limits to the ~97% level. Hence, we are able to accurately infer the space density of T dwarfs. We employ Monte Carlo tools to simulate the observed population of SDSS DR1 T dwarfs with 2MASS counterparts and find that the space density of T0-T8 dwarf systems is 0.0070+0.0032–0.0030pc–3 (95% confidence interval), i.e., about one per 140 pc3. Compared to predictions for the T dwarf space density that depend on various assumptions for the substellar mass function, this result is most consistent with models that assume a flat substellar mass function dN/dM∝M0.0. No >T8 dwarfs were discovered in the present cross-match, although less than one was expected in the limited area (2099 deg2) of SDSS DR1.

Abstract Copyright:

Journal keyword(s): stars: individual (2MASS J00521232+0012172) - stars: individual (2MASS J01040750-0053283) - stars: individual (2MASS J01262109+1428057) - stars: individual (2MASS J09175418+6028065) - stars: individual (2MASS J12144089+6316434) - stars: individual (2MASS J13243553+6358281) - stars: individual (2MASS J15461461+4932114) - Stars: Low-Mass, Brown Dwarfs - survey

VizieR on-line data: <Available at CDS (J/ApJ/676/1281): table1.dat table2.dat table3.dat table5.dat table6.dat table7.dat refs.dat>

Simbad objects: 53

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