Related papers: Limits on the Gas Disk Content of Two "Evolved" T …

We report results of a sensitive search for cold dust and molecular gas in the disks around 8 T Tauri stars in the high-latitude cloud MBM 12. Interferometric observations of 3 mm continuum emission in 5 fields containing 6 of the objects,…

We have carried out a sensitive search for gas emission lines at infrared and millimeter wavelengths for a sample of 15 young sun-like stars selected from our dust disk survey with the Spitzer Space Telescope. We have used mid-infrared…

Residual gas in disks around young stars can spin down stars, circularize the orbits of terrestrial planets, and whisk away the dusty debris that is expected to serve as a signpost of terrestrial planet formation. We have carried out a…

We report the detection of quiescent H_2 emission in the v=1-0 S(1) line at 2.12183 um in the circumstellar environment of two classical T Tauri stars, GG Tau A and LkCa 15, in high-resolution (R 60,000) spectra, bringing to four, including…

We report infrared spectroscopic observations of HD 105, a nearby ($\sim 40$ pc) and relatively young ($\sim 30$ Myr) G0 star with excess infrared continuum emission, which has been modeled as arising from an optically thin circumstellar…

We present a survey of mid-infrared gas-phase lines toward a sample of 76 circumstellar disks around low mass pre-main sequence stars from the Spitzer "Cores to Disks" legacy program. We report the first detections of [Ne II] and [Fe I]…

AIMS : To characterize the molecular environment of classical T Tauri stars in Lupus observed with the Spitzer Space Telescope and to search for gas-rich disks toward these sources. METHODS : Submillimeter observations of 12CO, 13CO and…

We present new X-ray and Far Ultraviolet (FUV) observations of T Tauri stars covering the age range 1 to 10 Myr. Our goals are to observationally constrain the intensity of radiation fields responsible for evaporating gas from the…

The interplay between T Tauri stars and their circumstellar disks, and how this impacts the onset of planet formation has yet to be established. We studied a seemingly old T Tauri star, PDS 111, and its disk. We analyzed optical, infrared,…

Astronomers have established that for a few million years newborn stars possess disks of orbiting gas and dust. Such disks, which are likely sites of planet formation, appear to disappear once these stars reach ages of 5-10 times 10^6 yr;…

Context. Edge-on disks offer a unique opportunity to directly examine their vertical structure, providing valuable insights into planet formation processes. We investigate the dust properties, as well as the CO and HCO$^+$ gas properties,…

We present submillimeter (CSO 350um) and millimeter (SEST 1.2 mm, OVRO 3 mm) photometry for 125 solar-type stars from the FEPS Spitzer Legacy program that have masses between ~0.5 and 2.0 Msun and ages from 3 Myr to 3 Gyr. Continuum…

We present Herschel PACS spectroscopy of the [OI] 63 micron gas-line for three circumstellar disk systems showing signs of significant disk evolution and/or planet formation: HR 8799, HD 377 and RX J1852.3-3700. [OI] is undetected toward HR…

We seek to establish the presence and properties of gas in the circumstellar disk orbiting T Cha, a nearby (d~110 pc), relatively evolved (age ~5-7 Myr) yet actively accreting 1.5 Msun T Tauri star. We used the APEX 12 m radiotelescope to…

We have detected circumstellar molecular gas around a small sample of T Tauri stars through aperture synthesis imaging of CO(2-1) emission at ~2-3'' resolution. RY Tauri, DL Tauri, DO Tauri, and AS 209 show resolved and elongated gaseous…

We investigate the evolution of circumstellar discs around T Tauri stars that are ejected from small stellar clusters within molecular clouds. In particular, we study how the interaction that leads to ejection may hasten the transition…

We present near-infrared spectra of the excess continuum emission from the innermost regions of classical T Tauri disks. In almost all cases, the shape of the excess is consistent with that of a single-temperature blackbody with T ~ 1400 K,…

We present ISO-SWS observations of H2 pure-rotational line emission from the disks around low and intermediate mass pre-main-sequence stars as well as from young stars thought to be surrounded by debris disks. We detect `warm' (T ~ 100-200…

Using the Spitzer Space Telescope, we have observed 90 weak-line and classical T Tauri stars in the vicinity of the Ophiuchus, Lupus, Chamaeleon, and Taurus star-forming regions as part of the Cores to Disks (c2d) Spitzer Legacy project. In…

We study the distribution and physical properties of molecular gas in the disc around the T Tauri star IM Lup on scales close to 200 AU. We investigate how well the gas and dust distributions compare and work towards a unified disc model…