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Related papers: Probing Disk Accretion in Young Brown Dwarfs

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We report the results of mid-IR observations with VISIR at the VLT of 10 ultracool dwarfs members of the nearby Upper Scorpius OB association in four filters ranging between 8.59 (PAH1) to 12.8 $\mu$m (Ne II), and one brown dwarf with…

We have carried out a Spitzer survey for brown dwarf (BD) disks in the ~5 Myr old Upper Scorpius (UpSco) star forming region, using IRS spectroscopy from 8 to 12\mu m and MIPS photometry at 24\mu m. Our sample consists of 35 confirmed very…

We report rotational periods for 16 young brown dwarfs in the nearby Upper Scorpius association, based on 72 days of high-cadence, high-precision photometry from the Kepler space telescope's K2 mission. The periods range from a few hours to…

Solar and Stellar Astrophysics · Physics 2015-08-26 Aleks Scholz , Veselin Kostov , Ray Jayawardhana , Koraljka Muzic

This paper discusses evidence for and properties of disks associated to brown dwarfs in the star-forming region rho-Oph. We selected nine objects fr om the ISOCAM survey of Bontemps et al. (2001) that have detections in the two mid-infrared…

Astrophysics · Physics 2009-11-07 A. Natta , L. Testi , F. Comeron , E. Oliva , F. D'Antona , C. Baffa , G. Comoretto , S. Gennari

The time evolution of the dependence of the mass accretion rate with the stellar mass and the disk mass represents a fundamental way to understand the evolution of protoplanetary disks and the formation of planets. In this work, we present…

Solar and Stellar Astrophysics · Physics 2024-02-19 V. Almendros-Abad , C. F. Manara , L. Testi , A. Natta , R. A. B. Claes , K. Muzic , E. Sanchis , J. M. Alcalá , A. Bayo , A. Scholz

(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 use Kepler/K2 lightcurves to measure rotation periods of brown dwarfs and very low mass stars in the Upper Scorpius star-forming region. Our sample comprises a total of 104 periods. Depending on the assumed age of Upper Scorpius, about a…

Earth and Planetary Astrophysics · Physics 2019-02-27 Keavin Moore , Aleks Scholz , Ray Jayawardhana

Over the past year, we have conducted a multi-faceted program to investigate the origin and early evolution of brown dwarfs. Using high-resolution Keck optical spectra of ~30 objects near and below the sub-stellar boundary in several…

As part of a multi-faceted program to investigate the origin and early evolution of sub-stellar objects, we present high-resolution Keck optical spectra of 14 very low mass sources in the IC 348 young cluster and the Taurus star-forming…

Astrophysics · Physics 2009-11-07 Ray Jayawardhana , Subhanjoy Mohanty , Gibor Basri

High resolution (lambda / Delta-lambda = 50,000) K-band spectra of massive, embedded, young stellar objects are presented. The present sample consists of four massive young stars located in nascent clusters powering Galactic giant H II…

Astrophysics · Physics 2009-11-10 R. D. Blum , C. L. Barbosa , A. Damineli , P. S. Conti , S. Ridgway

The Upper-Scorpius association (5-11 Myr) contains a unique population of low-mass (M<30 MJup) brown-dwarfs. The detailed relative characterization of their physical properties (mass, radius, temperature, composition, ongoing accretion)…

Using SpeX at the NASA Infrared Telescope Facility and the Spitzer Infrared Spectrograph, we have obtained infrared spectra from 0.7 to 30um for three young brown dwarfs in the TW Hydra Association (~10 Myr), 2M J1207-3932, 2M J1139-3159,…

Characterization of the properties of young brown dwarfs are important to constraining the formation of objects at the extreme low-mass end of the IMF. While young brown dwarfs share many properties with solar-mass T Tauri stars,…

Determining the mechanisms that drive the evolution of protoplanetary disks is a necessary step to understand how planets form. Here we measured the mass accretion rate for young stellar objects at age >5 Myr, a critical test for the…

We present observations of a circumstellar disk that is inclined close to edge-on around a young brown dwarf in the Taurus star-forming region. Using data obtained with SpeX at the NASA Infrared Telescope Facility, we find that the slope of…

It is now well established that many young brown dwarfs exhibit characteristics similar to classical T Tauri stars, including infrared excess from disks and emission lines related to accretion. Whether the same holds true for even lower…

Astrophysics · Physics 2009-11-11 Ray Jayawardhana , Valentin D. Ivanov

We present projected rotational velocities for 20 early-type (B8-A9) and 74 late-type (F2-M8) members of the ~5 Myr old Upper Scorpius OB Association derived from high dispersion optical spectra obtained with the High Resolution Echelle…

Solar and Stellar Astrophysics · Physics 2015-05-30 S. E. Dahm , Catherine L. Slesnick , R. J. White

We searched for binary companions to 20 young brown dwarfs in the Upper Scorpius association (145 pc, 5 Myr, nearest OB association) with the the Laser Guide Star adaptive optics system and the facility infrared camera NIRC2 on the 10 m…

Solar and Stellar Astrophysics · Physics 2015-05-27 Beth Biller , Katelyn Allers , Michael Liu , Laird Close , Trent Dupuy

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
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