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Research in Astronomy and Astrophysics 2017年第2期17卷 29-34页

作者： Chien-Hsiu Lee Chien-Cheng Lin subaru telescope National Astronomical Observatory of Japan Shanghai Astronomical Observatory Chinese Academy of Sciences

Eclipsing binaries provide a unique opportunity to determine fundamental stellar properties. In the era of wide-field cameras and all-sky imaging surveys, thousands of eclipsing binaries have been reported through light curve classification, yet their basic properties remain unexplored due to the ex- tensive efforts needed to follow them up spectroscopically. In this paper we investigate three M2-M3 type double-lined eclipsing binaries discovered by cross-matching eclipsing binaries from the Catalina Sky Survey with spectroscopically classified M dwarfs from the Large Sky Area Multi-Object Fiber Spectroscopic telescope survey data release one and two. Because these three M dwarf binaries are faint, we further acquire radial velocity measurements using GMOS on the Gemini North telescope with R ~4000, enabling us to determine the mass and radius of individual stellar components. By jointly fitting the light and radial velocity curves of these systems, we derive the mass and radius of the primary and secondary components of these three systems, in the range between 0.28-0.42 MQ and 0.29-0.67 R, respectively. Future observations with a high resolution spectrograph will help us pin down the uncertainties in their stellar parameters, and render these systems benchmarks to study M dwarfs, providing inputs to improving stellar models in the low mass regime, or establishing an empirical mass-radius relation for M dwarf stars.

关键词：（stars） binaries eclipsing

High resolution deep imaging of a bright radio quiet QSO at z～3

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Research in Astronomy and Astrophysics 2015年第5期15卷 673-686页

作者： Yi-Ping Wang Wei He Toru Yamada Ichi Tanaka Masanori Iye Tuo Ji Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Tohoku University Aramaki Aoba Sendai 980-8578 Japan subaru telescope National Astronomical Obs. of Japan 650 North A’ohoku Place Hilo Hawaii 96720 USA National Astronomical Obs. of Japan 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Polar Research Institute of China

We have obtained deep J and Ks-band images centered on a bright radio quiet QSO UM 402 （Zem = 2.856） using the IRCS camera and adaptive optics systems that are part of the subaru telescope, as well as retrieved WFC3/F140W archive images of this object. A faint galaxy （ink = 23.32 ±0.05 in the Vega magnitude system） that lies ～2.4″north of the QSO sightline has been clearly resolved in all three deep high resolution datasets, and appears as an irregular galaxy with two close components in the Ks-band images （separation ～ 0.31″）. Given the small impact parameter （b = 19.6 kpc, at Zlls = 2.531）, as well as the red color of （J - Ks）vega ～1.6, it might be a candidate galaxy giving rise to the Lyman Limit system absorption at Zabs = 2.531 seen in the QSO spectrum. After carefully subtracting the point spread function from the QSO images, the host galaxy of this bright radio quiet QSO at z ～ 3 was marginally revealed. We placed a lower limit on the host component of mk～ 23.3 according to our analyses.

关键词： galaxies active -- galaxies high redshift -- quasars general -- instru- mentation adaptive optics

Near-infrared imaging survey of faint companions around young dwarfs in the Pleiades cluster

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Research in Astronomy and Astrophysics 2011年第3期11卷 335-344页

作者： Yoichi Itoh Yumiko Oasa Hitoshi Funayama Masahiko Hayashi Misato Fukagawa Toshio Hashiguchi Thayne Currie Graduate School of Science Kobe University1-1 RokkodaiNada-kuKobe 657-8501Japan Faculty of Education Saitama University255 Shimo-OkuboSakura-kuSaitamaSaitama 338-8570Japan subaru telescope 650 North A'ohoku PlaceHiloHawaii 96720USA School of Mathematical and Physical Science Graduate University for Advanced Studies(Sokendai)2-21-1 OsawaMitakaTokyo 181-8588Japan Graduate School of Science Osaka UniversityMachikaneyamaToyonakaOsaka 560-0043Japan NASA-Goddard Space Flight Center

We conducted a near-infrared imaging survey of 11 young dwarfs in the Pleiades cluster using the subaru telescope and the near-infrared coronagraph imager. We found ten faint point sources,with magnitudes as faint as 20 mag in the K-band,with around seven dwarfs.Comparison with the Spitzer archive images revealed that a pair of the faint sources around V 1171 Tau is very red in infrared wavelengths,which indicates very low-mass young stellar objects.However,the results of our follow-up proper motion measurements implied that the central star and the faint sources do not share common proper motions,suggesting that they are not physically associated.

关键词： planetary systems：formation—techniques：high angular resolution

Near-infrared polarimetry of the GG Tauri A binary system

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Research in Astronomy and Astrophysics 2014年第11期14卷 1438-1446页

作者： Yoichi Itoh Yumiko Oasa Tomoyuki Kudo Nobuhiko Kusakabe Jun Hashimoto Lyu Abe Wolfgang Brandner Timothy D.Brandt Joseph C.Carson Sebastian Egner Markus Feldt Carol A.Grady Olivier Guyon Yutaka Hayano Masahiko Hayashi Saeko S.Hayashi Thomas Henning Klaus W.Hodapp Miki Ishii Masanori Iye Markus Janson Ryo Kandori Gillian R.Knapp Masayuki Kuzuhara Jungmi Kwon Taro Matsuo Michael W.McElwain Shoken Miyama Jun-Ichi Morino Amaya Moro-Martin Tetsuo Nishimura Tae-Soo Pyo Eugene Serabyn Takuya Suenaga Hiroshi Suto Ryuji Suzuki Yasuhiro H.Takahashi Naruhisa Takato Hiroshi Terada Christian Thalmann Daigo Tomono Edwin L.Turner Makoto Watanabe John Wisniewski Toru Yamada Satoshi Mayama Thayne Currie Hideki Takami Tomonori Usuda Motohide Tamura Nishi-Harima Astronomical Observatory Center for AstronomyUniversity of Hyogo407-2NishigaichiSayoHyogo 679-5313Japan Faculty of Education Saitama University255 Shimo-OkuboSakuraSaitamaSaitama338-8570Japan subaru telescope National Astronomical Observatory of Japan650 North Ahoku PlaceHiloHI 96720USA National Astronomical Observatory of Japan 2-21-1OsawaMitakaTokyo181-8588Japan H.L.Dodge Department of Physics & Astronomy University of Oklahoma440 W Brooks St.NormanOK 73019USA Laboratoire Lagrange (UMR 7293) Universit de Nice-Sophia AntipolisCNRSObservatoire de la Cote d’Azur28 avenue Valrose06108 Nice Cedex 2France Max Planck Institute for Astronomy Knigstuhl 1769117 HeidelbergGermany Department of Astrophysical Science Princeton UniversityPeyton HallIvy LanePrincetonNJ 08544USA Department of Physics and Astronomy College of Charleston58 Coming St.CharlestonSC29424USA subaru telescope National Astronomical Observatory of Japan650 North A’ohoku PlaceHiloHI 96720USA Exoplanets and Stellar Astrophysics Laboratory Code 667Goddard Space Flight CenterGreenbeltMD 20771USA Eureka Scientific 2452 DelmerSuite 100Oakland CA 96002USA Goddard Center for Astrobiology GreenbeltMD 20771USA Institute for Astronomy University of Hawaii640 N.Aohoku PlaceHiloHI 96720USA Department of Earth and Planetary Sciences Tokyo Institute of TechnologyOokayamaMeguro-kuTokyo 152-8551Japan Department of Astronomy Kyoto UniversityKitashirakawa-Oiwake-choSakyo-kuKyotoKyoto 606-8502Japan Hiroshima University 1-3-2KagamiyamaHigashihiroshimaHiroshima 739-8511Japan Department of Astrophysics CAB-CSIC/INTA28850 Torrejón de ArdozMadridSpain Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA91109USA Department of Astronomical Science The Graduate University for Advanced Studies2-21-1OsawaMitakaTokyo181-8588Japan Department of Astronomy The University of Tokyo7-3-1HongoBunkyo-kuTokyo113-0033Japan Astronomical Institute "Anton Pannekoek" University

A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the subaru telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.

关键词： stars individual （GG Tauri） -- stars pre-maln sequence - techniques high angular resolution