Related papers: Evidence for a T Tauri Phase in Young Brown Dwarfs

We have carried out sensitive 1.3 mm observations of 20 young brown dwarfs in the Taurus star-forming region, representing the largest sample of young substellar objects targeted in a deep millimeter continuum survey to date. Under standard…

We compare accretion shock models with optical and ultraviolet spectra of pre-main sequence stars to (1) make the first determinations of accretion rates in intermediate mass T Tauri stars from continuum emission, and (2) derive improved…

Classical T Tauri Stars (CTTSs) are highly variable stars that possess gas- and dust-rich disks from which planets form. Much of their variability is driven by mass accretion from the surrounding disk, a process that is still not entirely…

With Herschel/PACS 134 low mass members of the Taurus star-forming region spanning the M4-L0 spectral type range and covering the transition from low mass stars to brown dwarfs were observed. Combining the new Herschel results with other…

Classical T Tauri stars are low-mass objects, which are still accreting material from the surrounding circumstellar disk. The accretion process is essential in the formation of Sun-like stars and in setting the properties of the disk at the…

Studies of disks around young brown dwarfs are of paramount importance to our understanding of the origin, diversity and early evolution of sub-stellar objects. Here we present first results from a systematic search for disk emission in a…

Condensate clouds are a salient feature of L dwarf atmospheres, but have been assumed to play little role in shaping the spectra of the coldest T-type brown dwarfs. Here we report evidence of condensate opacity in the near-infrared spectrum…

We report the discovery of five T Tauri star systems, two of which are resolved binaries, in the vicinity of the nearest known region of recent star formation, the TW Hydrae Association. The newly discovered systems display the same…

We present the results of a deep, optical/IR wide field imaging survey of selected fields in the nearby (d ~ 140 pc) Taurus star-forming region. We report the discovery of 9 new members with spectral types M5.75-M9.5. We derive an Initial…

We present moderate-resolution ($R$$\sim$4000-5000) near-infrared integral field spectroscopy of the young (1-5 Myr) 6-14 $M_\mathrm{Jup}$ companions ROXs 42B b and FW Tau b obtained with Keck/OSIRIS and Gemini-North/NIFS. The spectrum of…

The C IV doublet in the UV has long been associated with accretion in T Tauri stars. However, it is still unclear where and how the lines are formed. Here, we present a new C IV line model based on the currently available accretion shock…

Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time of the mass accretion rate onto TW Hya, the nearest…

We present a high dispersion optical spectrum of St 34 and identify the system as a spectroscopic binary with components of similar luminosity and temperature (both M3+/-0.5). Based on kinematics, signatures of accretion, and location on an…

(Abridged) Optical spectra of classical T Tauri stars (cTTS) are rich in emission lines of low-excitation species that are composed of narrow and broad components, related to two regions with different kinematics, densities, and…

We have combined new I, J, H, and Ks imaging of portions of the Chamaeleon II, Lupus I, and Ophiuchus star-forming clouds with 3.6 to 24 micron imaging from the Spitzer Legacy Program, "From Molecular Clouds to Planet Forming Disks", to…

We investigate ongoing accretion activity in young stars in the TW Hydrae association (TWA, ~8-10 Myr), an ideal target to probe the final stages of disk accretion down to brown dwarf masses. Our sample comprises eleven TWA members with…

A total of 81 DA white dwarfs have been observed with the Cosmic Origins Spectrograph on the Hubble Space Telescope in a snapshot program. The targets were selected to be in the $T_{\rm eff}$ range from 17000 - 25000 K, where optical metal…

We describe the results of a very deep imaging survey of the Trapezium Cluster in the IJH bands, using the UKIRT high resolution camera UFTI. Approximately 32% of the 515 point sources detected are brown dwarf candidates, including several…

Forty new low mass members with spectral types ranging from M4-M9 have been confirmed in the Orion Molecular Cloud 2/3 region. Through deep, I, z', J, H, K photometry of a 20' x 20' field in OMC 2/3, we selected brown dwarf candidates for…

Aims: We want to detect and quantify observables related to accretion processes occurring locally in circumstellar disks, which could be attributed to young forming planets. We focus on objects known to host protoplanet candidates and/or…