A CLOSE COMPANION SEARCH AROUND L DWARFS USING APERTURE MASKING INTERFEROMETRY AND PALOMAR LASER GUIDE STAR ADAPTIVE OPTICS

被引：26

作者：

Bernat, David ^{[1
]}

Bouchez, Antonin H. ^{[3
]}

Ireland, Michael ^{[4
]}

Tuthill, Peter ^{[4
]}

Martinache, Frantz ^{[5
]}

Angione, John ^{[3
,6
]}

Burruss, Rick S. ^{[3
,6
]}

Cromer, John L. ^{[3
]}

Dekany, Richard G. ^{[3
]}

Guiwits, Stephen R. ^{[3
,6
]}

Henning, John R. ^{[2
,3
]}

Hickey, Jeff ^{[2
,3
]}

Kibblewhite, Edward ^{[3
,7
]}

McKenna, Daniel L. ^{[2
,3
]}

Moore, Anna M. ^{[3
]}

Petrie, Harold L. ^{[2
,3
]}

Roberts, Jennifer ^{[3
,6
]}

Shelton, J. Chris ^{[3
,6
]}

Thicksten, Robert P. ^{[2
,3
]}

Trinh, Thang ^{[3
,6
]}

Tripathi, Renu ^{[2
,3
]}

Troy, Mitchell ^{[3
,6
]}

Truong, Tuan ^{[3
,6
]}

Velur, Viswa ^{[3
]}

Lloyd, James P. ^{[1
]}

机构：

[1] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA

[2] CALTECH, Caltech Opt Observ, Pasadena, CA 91125 USA

[3] CALTECH, Palomar Observ, Palomar Laser Guide Star Adapt Opt Team, Palomar Mt, CA 92060 USA

[4] Univ Sydney, Sch Phys, Sydney Inst Astrophys, Sydney, NSW 2006, Australia

[5] Natl Inst Nat Sci, Natl Astron Observ Japan, Hilo, HI 96720 USA

[6] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA

[7] Univ Chicago, Chicago, IL 60637 USA

来源：

ASTROPHYSICAL JOURNAL | 2010年 / 715卷 / 02期

基金：

美国国家科学基金会; 美国国家航空航天局;

关键词：

binaries: general; brown dwarfs; stars: low-mass; techniques: high angular resolution; LOW-MASS STARS; BROWN DWARF; DYNAMICAL MASS; ULTRACOOL DWARFS; BINARY-SYSTEMS; GJ; 802B; MULTIPLICITY;

D O I：

10.1088/0004-637X/715/2/724

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present a close companion search around 16 known early L dwarfs using aperture masking interferometry with Palomar laser guide star adaptive optics (LGS AO). The use of aperture masking allows the detection of close binaries, corresponding to projected physical separations of 0.6-10.0 AU for the targets of our survey. This survey achieved median contrast limits of Delta K similar to 2.3 for separations between 1.2 lambda/D-4 lambda/D and Delta K similar to 1.4 at 23 lambda/D. We present four candidate binaries detected with moderate-to- high confidence (90%-98%). Two have projected physical separations less than 1.5 AU. This may indicate that tight-separation binaries contribute more significantly to the binary fraction than currently assumed, consistent with spectroscopic and photometric overluminosity studies. Ten targets of this survey have previously been observed with the Hubble Space Telescope as part of companion searches. We use the increased resolution of aperture masking to search for close or dim companions that would be obscured by full aperture imaging, finding two candidate binaries. This survey is the first application of aperture masking with LGS AO at Palomar. Several new techniques for the analysis of aperture masking data in the low signal-to-noise regime are explored.

引用

页码：724 / 735

页数：12

共 30 条

[1] Star formation via the little guy: A Bayesian study of ultracool dwarf imaging surveys for companions [J].