English
Related papers

Related papers: OTS44: Disk and accretion at the planetary border

200 papers

Recent observations show a strong correlation between stellar mass and accretion rate in young stellar and sub-stellar objects, with the scaling $\dot{M}_{acc} \propto M_*^2$ holding over more than four orders of magnitude in accretion…

Astrophysics · Physics 2009-11-11 R. D. Alexander , P. J. Armitage

Using the largest high-resolution spectroscopic sample to date of young, very low mass stars (VLMS) and brown dwarfs (BDs), we investigate disk accretion in objects ranging from just above the hydrogen-burning limit all the way to nearly…

Astrophysics · Physics 2008-11-26 Subhanjoy Mohanty , Ray Jayawardhana , Gibor Basri

We present ALMA continuum and spectral line data at 0.89 mm and 3.2 mm for three disks surrounding young brown dwarfs and very low mass stars in the Taurus star forming region. Dust thermal emission is detected and spatially resolved for…

Earth and Planetary Astrophysics · Physics 2015-06-19 L. Ricci , L. Testi , A. Natta , A. Scholz , I. de Gregorio-Monsalvo , A. Isella

(Abridged) We have completed the first systematic survey for disks around spectroscopically identified young brown dwarfs and very low mass stars. We have obtained L'-band (3.8 um) imaging for 38 very cool objects in IC 348 and Taurus. Our…

Astrophysics · Physics 2008-11-26 Michael C. Liu , Joan Najita , Alan T. Tokunaga

We present high resolution optical spectra obtained with the HIRES spectrograph on the Keck I telescope of low mass T Tauri stars and brown dwarfs (LMTTs) in Taurus-Auriga. Of particular interest is the previously classified "continuum T…

Astrophysics · Physics 2009-11-07 Russel White , Gibor Basri

The detection of a dust disc around G29-38 and transits from debris orbiting WD1145+017 confirmed that the photospheric trace metals found in many white dwarfs arise from the accretion of tidally disrupted planetesimals. The composition of…

We report FUV, optical, and NIR observations of three T Tauri stars in the Orion OB1b subassociation with H$\alpha$ equivalent widths consistent with low or absent accretion and various degrees of excess flux in the mid-infrared. We aim to…

The full disk, full of gas and dust, determines the upper limit of planet masses, and its lifetime is critical for planet formation, especially for giant planets. In this work, we studied the evolutionary timescales of the full disks of T…

Solar and Stellar Astrophysics · Physics 2023-12-25 Hasitieer Haerken , Guang-Wei Li , Min Li , Fuqing Duan , Yongheng Zhao

We review the present knowledge of disk accretion in young low mass stars, and in particular, the mass accretion rate and its evolution with time. The methods used to obtain mass accretion rates from ultraviolet excesses and emission lines…

Astrophysics · Physics 2007-05-23 Nuria Calvet , Lee Hartmann , Stephen E. Strom

The aim of this paper is to provide a measurement of the mass accretion rate in a large, complete sample of objects in the core of the star forming region Rho-Oph. The sample includes most of the objects (104 out of 111) with evidence of a…

Astrophysics · Physics 2009-11-11 A. Natta , L. Testi , S. Randich

We present some results from a systematic survey for disks around spectroscopically identified young brown dwarfs and very low mass stars. We find that ~75% of our sample show intrinsic IR excesses, indicative of circum(sub)stellar disks.…

Astrophysics · Physics 2007-05-23 Michael C. Liu

We present new far-ultraviolet observations of the young M8 brown dwarf 2MASS J12073346-3932539, which is surrounded by an accretion disk. The data were obtained using the Hubble Space Telescope-Cosmic Origins Spectrograph. Moderate…

Solar and Stellar Astrophysics · Physics 2015-05-18 Kevin France , Jeffrey L. Linksy , Alexander Brown , Cynthia S. Froning , Stephane Beland

We have obtained a series of high-resolution optical spectra for the brown dwarf 2MASSW J1207334-393254 (2M1207) using the ESO Very Large Telescope with the UVES spectrograph during two consecutive observing nights (time resolution of ~12…

Astrophysics · Physics 2009-11-13 Beate Stelzer , Alexander Scholz , Ray Jayawardhana

Recent observations point to the presence of structured dust grains in the discs surrounding young brown dwarfs, thus implying that the first stages of planet formation take place also in the sub-stellar regime. Here, we investigate the…

Astrophysics · Physics 2009-11-13 Matthew J. Payne , Giuseppe Lodato

We present a near-infrared direct imaging search for accretion signatures of possible protoplanets around the young stellar object (YSO) TW Hya, a multi-ring disk exhibiting evidence of planet formation. The Pa$\beta$ line (1.282 $\mu$m) is…

Earth and Planetary Astrophysics · Physics 2017-08-23 Taichi Uyama , Takayuki Tanigawa , Jun Hashimoto , Motohide Tamura , Yuhiko Aoyama , Timothy D. Brandt , Masato Ishizuka

We have imaged two bona-fide brown dwarfs with TReCS/GEMINI-S and find mid-infrared excess emission that can be explained by optically thick dust disk models. In the case of the young ($\approx$2Myr) Cha H$\alpha$1 we measure fluxes at…

Measurements of accretion rates onto planetary mass objects may distinguish between different planet formation mechanisms, which predict different accretion histories. In this Letter, we use \HST/WFC3 UVIS optical photometry to measure…

Solar and Stellar Astrophysics · Physics 2015-06-18 Yifan Zhou , Gregory J. Herczeg , Adam L. Kraus , Stanimir Metchev , Kelle Cruz

Accretion disks in white dwarf systems are believed to be tilted. In a recent publication, the lift force has been suggested to be a source to disk tilt, a source that is likely relevant to all accretion disk systems. Lift is generated by…

Earth and Planetary Astrophysics · Physics 2011-04-05 M. M. Montgomery

We present an analysis of the accretion properties of the members of the TW Hydrae association. The Halpha emission line profile provides explicit evidence of an active accretion flow in 3 out of 23 observed members of the association; we…

Astrophysics · Physics 2007-05-23 James Muzerolle , Lynne Hillenbrand , Nuria Calvet , Lee Hartmann , Cesar Briceno

In a previous study, we found that the detached post-common-envelope binary LTT 560 displays an Halpha emission line consisting of two anti-phased components. While one of them was clearly caused by stellar activity from the secondary…

Solar and Stellar Astrophysics · Physics 2011-09-09 C. Tappert , B. T. Gänsicke , L. Schmidtobreick , T. Ribeiro