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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…

We present ALMA 880 micron continuum observations of 20 K and M-type stars in the Upper Scorpius OB association that are surrounded by protoplanetary disks. These data are used to measure the dust content in disks around low mass stars…

Solar and Stellar Astrophysics · Physics 2015-06-19 John M. Carpenter , Luca Ricci , Andrea Isella

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 the results of ALMA band 7 observations of dust and CO gas in the disks around 7 objects with spectral types ranging between M5.5 and M7.5 in Upper Scorpius OB1, and one M3 star in Ophiuchus. We detect unresolved continuum…

Solar and Stellar Astrophysics · Physics 2016-09-09 G. van der Plas , F. Menard , K. Ward-Duong , J. Bulger , P. M Harvey , C. Pinte , J. Patience , A. Hales , S. Casassus

Aims : We want to investigate whether brown dwarfs (BDs) form like stars or are ejected embryos. We study the presence of disks around BDs in the Taurus cloud, and discuss implications for substellar formation models. Methods : We use…

Using the Spitzer Infrared Spectrograph, we have performed mid-infrared spectroscopy on the young binary brown dwarf 2MASS J04414489+2301513 (15 AU) in the Taurus star-forming region. The spectrum exhibits excess continuum emission that…

Earth and Planetary Astrophysics · Physics 2015-05-20 Lucia Adame , Nuria Calvet , K. L. Luhman , Paola D'Alessio , Elise Furlan , M. K. McClure , Lee Hartmann , William J. Forrest , Dan M. Watson

We present new results on how the presence of stellar companions affects disk evolution based on a study of the 5-11 Myr old Upper Scorpius OB Association. Of the 50 G0-M3 Upper Sco members with disks in our sample, only seven host a…

The Atacama Large Millimeter/submillimeter Array (ALMA) large program AGE-PRO explores protoplanetary disk evolution by studying gas and dust across various ages. This work focuses on ten evolved disks in Upper Scorpius, observed in dust…

The study of the properties of disks around young brown dwarfs can provide important clues on the formation of these very low-mass objects and on the possibility of forming planetary systems around them. The presence of warm dusty disks…

Solar and Stellar Astrophysics · Physics 2016-10-05 L. Testi , A. Natta , A. Scholz , M. Tazzari , L. Ricci , I. de Gregorio Monsalvo

Disks around brown dwarfs (BDs) are excellent laboratories to study the first steps of planet formation in cold and low-mass disk conditions. The radial-drift velocities of dust particles in BD disks are higher than in disks around more…

Earth and Planetary Astrophysics · Physics 2017-09-13 P. Pinilla , L. H. Quiroga-Nuñez , M. Benisty , A. Natta , L. Ricci , Th. Henning , G. van der Plas , T. Birnstiel , L. Testi , K. Ward-Duong

We present detailed modeling of the spatial distributions of gas and dust in 57 circumstellar disks in the Upper Scorpius OB Association observed with ALMA at sub-millimeter wavelengths. We fit power-law models to the dust surface density…

Solar and Stellar Astrophysics · Physics 2017-12-27 Scott A. Barenfeld , John M. Carpenter , Anneila I. Sargent , Andrea Isella , Luca Ricci

Aims. The brown dwarf (BD) formation process has not yet been completely understood. To shed more light on the differences and similarities between star and BD formation processes, we study and compare the disk fraction among both kinds of…

We present MIPS 24um and 70um photometry for 205 members of the Upper Scorpius OB Association. These data are combined with published MIPS photometry for 15 additional association members to assess the frequency of circumstellar disks…

Solar and Stellar Astrophysics · Physics 2014-11-20 John M. Carpenter , Eric E. Mamajek , Lynne A. Hillenbrand , Michael R. Meyer

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

Recent surveys have identified sub-stellar objects down to planetary masses in nearby star-forming regions. Reliable determination of the disk frequency in young brown dwarfs is of paramount importance to understanding their origin. Here we…

Astrophysics · Physics 2016-08-30 Ray Jayawardhana , David R. Ardila , Beate Stelzer , Karl E. Haisch

We present accurate mid-infrared observations of the disk around the young, bona-fide brown dwarf CFHT-BD-Tau 4. We report GEMINI/T-ReCS measurements in the 7.9, 10.4 and 12.3 micron filters, from which we infer the presence of a prominent,…

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)…

We report Spitzer Space Telescope IRAC 3.6, 4.5, 5.8 and 8 um and MIPS 24 and 70 um observations of the 32 Ori Group, a recently discovered nearby stellar association situated towards northern Orion. The proximity of the group (~93 pc) has…

Solar and Stellar Astrophysics · Physics 2016-12-22 Alexander J. Shvonski , Eric E. Mamajek , Jinyoung Serena Kim , Michael R. Meyer , Mark J. Pecaut

We present new 890 $\mu m$ continuum ALMA observations of 5 brown dwarfs (BDs) with infrared excess in Lupus I and III -- which, in combination with 4 BDs previously observed, allowed us to study the mm properties of the full known BD disk…

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…