Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1051/0004-6361/201525791 |
MOA-2007-BLG-197: Exploring the brown dwarf desert | |
Ranc, C.1,2; Cassan, A.1,2; Albrow, M. D.3; Kubas, D.1,2; Bond, I. A.4; Batista, V.1,2; Beaulieu, J. -P.1,2; Bennett, D. P.5; Dominik, M.6; Dong, Subo7; Fouque, P.8,9; Gould, A.10; Greenhill, J.11; Jorgensen, U. G.12; Kains, N.6,13; Menzies, J.14; Sumi, T.15; Bachelet, E.16; Coutures, C.1,2; Dieters, S.1,2; Prester, D. Dominis17; Donatowicz, J.18; Gaudi, B. S.10; Han, C.19; Hundertmark, M.6,12; Horne, K.6; Kane, S. R.20; Lee, C. -U.21; Marquette, J. -B.1,2; Park, B. -G.21; Pollard, K. P.3; Sahu, K. C.13; Street, R.22; Tsapras, Y.22,23; Wambsganss, J.23; Williams, A.24,25; Zub, M.23; Abe, F.26; Fukui, A.27; Itow, Y.26; Masuda, K.26; Matsubara, Y.26; Muraki, Y.26; Ohnishi, K.28; Rattenbury, N.29; Saito, To30; Sullivan, D. J.31; Sweatman, W. L.32; Tristram, P. J.33; Yock, P. C. M.29; Yonehara, A.34 | |
通讯作者 | Cassan, A. |
来源期刊 | ASTRONOMY & ASTROPHYSICS
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ISSN | 1432-0746 |
出版年 | 2015 |
卷号 | 580 |
英文摘要 | We present the analysis of MOA-2007-BLG-197Lb, the first brown dwarf companion to a Sun-like star detected through gravitational microlensing. The event was alerted and followed-up photometrically by a network of telescopes from the PLANET, MOA, and mu FUN collaborations, and observed at high angular resolution using the NaCo instrument at the VLT. From the modelling of the microlensing light curve, we derived basic parameters such as, the binary lens separation in Einstein radius units (s similar or equal to 1.13), the mass ratio q = (4.732 +/- 0.020) x 10(-2) and the Einstein radius crossing time (t(E) similar or equal to 82 d). Because of this long time scale, we took annual parallax and orbital motion of the lens in the models into account, as well as finite source effects that were clearly detected during the source caustic exit. To recover the lens system’s physical parameters, we combined the resulting light curve best-fit parameters with (J, H, K-s) magnitudes obtained with VLT NaCo and calibrated using IRSF and 2MASS data. From this analysis, we derived a lens total mass of 0.86 +/- 0.04 M-circle dot and a lens distance of D-L = 4.2 +/- 0.3 kpc. We find that the companion of MOA-2007-BLG-197L is a brown dwarf of 41 +/- 2 M-J observed at a projected separation of a(perpendicular to) = 4.3 +/- 0.1 AU, and orbits a 0.82 +/- 0.04 M-circle dot G-K dwarf star. We then placed the companion of MOA-2007-BLG-197L in a mass-period diagram consisting of all brown dwarf companions detected so far through different techniques, including microlensing, transit, radial velocity, and direct imaging (most of these objects orbit solar-type stars). To study the statistical properties of this population, we performed a two-dimensional, non-parametric probability density distribution fit to the data, which draws a structured brown dwarf landscape. We confirm the existence of a region that is strongly depleted in objects at short periods and intermediate masses (P less than or similar to 30 d, M similar to 30-60 M-J), but also find an accumulation of objects around P similar to 500 d and M similar to 20 M-J, as well as another depletion region at long orbital periods (P greater than or similar to 500 d) and high masses (M greater than or similar to 50 M-J). While these data provide important clues on the different physical mechanisms of formation (or destruction) that shape the brown dwarf desert, more data are needed to establish their relative importance, in particular as a function of host star mass. Future microlensing surveys should soon provide more detections, in particular for red dwarf hosts, thus uniquely complementing the solar-type host sample. |
英文关键词 | planets and satellites: detection gravitational lensing: micro brown dwarfs |
类型 | Article |
语种 | 英语 |
国家 | France ; New Zealand ; USA ; Scotland ; Peoples R China ; Australia ; Denmark ; South Africa ; Japan ; Qatar ; Croatia ; Austria ; South Korea ; Germany |
收录类别 | SCI-E |
WOS记录号 | WOS:000360020200125 |
WOS关键词 | MICROLENSING LIGHT CURVES ; GALACTIC BULGE ; IMAGE SUBTRACTION ; PLANET PHOTOMETRY ; EVENTS ; BINARY ; MASS ; GIANT ; STARS ; MISSION |
WOS类目 | Astronomy & Astrophysics |
WOS研究方向 | Astronomy & Astrophysics |
来源机构 | 北京大学 ; E17 |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/186016 |
作者单位 | 1.Univ Paris 06, Sorbonne Univ, F-75014 Paris, France; 2.Inst Astrophys Paris, CNRS, UMR 7095, F-75014 Paris, France; 3.Univ Canterbury, Dept Phys & Astron, Christchurch 8020, New Zealand; 4.Massey Univ, Inst Nat & Math Sci, Auckland, New Zealand; 5.Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA; 6.Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland; 7.Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China; 8.Univ Toulouse, CNRS, IRAP, F-31400 Toulouse, France; 9.Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA; 10.Ohio State Univ, Dept Astron, Columbus, OH 43210 USA; 11.Univ Tasmania, Sch Math & Phys, Hobart, Tas 7001, Australia; 12.Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen O, Denmark; 13.Space Telescope Sci Inst, Baltimore, MD 21218 USA; 14.S African Astron Observ, ZA-7935 Observatory, South Africa; 15.Osaka Univ, Grad Sch Sci, Dept Earth & Space Sci, Toyonaka, Osaka 5600043, Japan; 16.Qatar Fdn, Qatar Environm & Energy Res Inst, Doha, Qatar; 17.Univ Rijeka, Dept Phys, Rijeka 51000, Croatia; 18.Vienna Univ Technol, Dept Comp, A-1040 Vienna, Austria; 19.Chungbuk Natl Univ, Dept Phys, Cheongju 371763, South Korea; 20.San Francisco State Univ, Dept Phys & Astron, San Francisco, CA 94132 USA; 21.Korea Astron & Space Sci Inst, Taejon, South Korea; 22.Las Cumbers Observ Global Telescope Network, Goleta, CA 93117 USA; 23.Univ Heidelberg ZAH, Zentrum Astron, Astron Rechen Inst, D-69120 Heidelberg, Germany; 24.Perth Observ, Perth, WA 6076, Australia; 25.Curtin Univ, Int Ctr Radio Astron Res, Bentley, WA 6102, Australia; 26.Nagoya Univ, Solar Terr Environm Lab, Nagoya, Aichi 4648601, Japan; 27.Natl Astron Observ Japan, Okayama Astrophys Observ, Asakuchi, Okayama 7190232, Japan; 28.Nagano Natl Coll Technol, Nagano 3818550, Japan; 29.Univ Auckland, Dept Phys, Auckland 1010, New Zealand; 30.Tokyo Metropolitan Coll Aeronaut, Tokyo 1168523, Japan; 31.Victoria Univ, Sch Chem & Phys Sci, Wellington 6147, New Zealand; 32.Massey Univ Albany, Inst Informat & Math Sci, Auckland 0745, New Zealand; 33.Mt John Univ Observ, Lake Tekapo 8770, New Zealand; 34.Kyoto Sangyo Univ, Fac Sci, Dept Phys, Kyoto 6038555, Japan |
推荐引用方式 GB/T 7714 | Ranc, C.,Cassan, A.,Albrow, M. D.,et al. MOA-2007-BLG-197: Exploring the brown dwarf desert[J]. 北京大学, E17,2015,580. |
APA | Ranc, C..,Cassan, A..,Albrow, M. D..,Kubas, D..,Bond, I. A..,...&Yonehara, A..(2015).MOA-2007-BLG-197: Exploring the brown dwarf desert.ASTRONOMY & ASTROPHYSICS,580. |
MLA | Ranc, C.,et al."MOA-2007-BLG-197: Exploring the brown dwarf desert".ASTRONOMY & ASTROPHYSICS 580(2015). |
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