Related papers: The Ionization Fraction in the DM Tau Protoplaneta…
Context: Investigating the vertical distribution of molecular content in protoplanetary disks remains difficult in most disks mildly inclined along the line of sight. In contrast, edge-on disks provide a direct (tomographic) view of the 2D…
The distributions of deuterated molecules in protoplanetary disks are expected to depend on the molecular formation pathways. We use observations of spatially resolved DCN emission from the disk around TW Hya, acquired during ALMA Science…
We study the content in S-bearing molecules of protoplanetary disks around low-mass stars. We used the new IRAM 30-m receiver EMIR to perform simultaneous observations of the $1_{10}-1_{01}$ line of H$_2$S at 168.8 GHz and $2_{23}-1_{12}$…
The overall properties of disks surrounding intermediate PMS stars (HAe) are not yet well constrained by current observations. The disk inclination, which significantly affect SED modeling, is often unknown. We attempted to resolve the…
We present an analysis of high-resolution spectroscopy of several bright T Tauri stars using the VLT/CRIRES and Keck/NIRSPEC spectrographs, revealing the first detections of emission from HCN and C2H2 in circumstellar disks at near-infrared…
Many planets orbit within an AU of their stars, raising questions about their origins. Particularly puzzling are the planets found near the silicate sublimation front. We investigate conditions near the front in the protostellar disk around…
We present a new SMA survey of 47 Class II sources in the Taurus-Auriga region. Our observations made 12 independent samples of flux densities over the 200-400 GHz frequency range. We tightly constrained the spectral indices of most sources…
We present an observational and theoretical study of the ionization fraction in several massive cores located in regions that are currently forming stellar clusters. Maps of the emission from the J = 1-> O transitions of C18O, DCO+, N2H+,…
Mid-infrared imaging traces the sub-micron and micron sized dust grains in protoplanetary disks and it offers constraints on the geometrical properties of the disks and potential companions, particularly if those companions have…
We investigate the chemistry of ion molecules in protoplanetary disks, motivated by the detection of N$_2$H$^+$ ring around TW Hya. While the ring inner radius coincides with the CO snow line, it is not apparent why N$_2$H$^+$ is abundant…
The thermal instability of accretion disks is widely used to explain the activity of cataclysmic variables, but its development in protoplanetary disks has been studied in less detail. We present a semi-analytical stationary model for…
Theoretical models and observations suggest that the abundances of molecular ions in protoplanetary disks should be highly sensitive to the variable ionization conditions set by the young central star. We present a search for temporal flux…
Physical processes that redistribute or remove angular momentum from protoplanetary disks can drive mass accretion onto the star and affect the outcome of planet formation. Despite ubiquitous evidence that protoplanetary disks are engaged…
We present the most sensitive 3 mm-survey to date of protoplanetary disks carried in the Taurus-Auriga star forming region (average rms of about 0.3 mJy), using the IRAM PdBI. With our high detection rate of 17/19, we provide the first…
Ionized interstellar gas is an important component of the interstellar medium and its lifecycle. The recent evidence for a widely distributed highly ionized warm interstellar gas with a density intermediate between the warm ionized medium…
We present spectrally resolved Herschel/HIFI observations of the young multiple system T Tau in atomic and molecular lines. While CO, H2O, [C II], and SO lines trace the envelope and the outflowing gas up to velocities of 33 km/s with…
DR Tau has been noted for its unusually high variability in comparison with other T Tauri stars. Although it is one of the most extensively studied pre-main sequence stars, observations with millimeter interferometry have so far been…
We report the detection of quiescent H2 emission in a spatially resolved ring-like structure within 100 AU of T Tau N. We present evidence to show that the emission most likely arises from shocks in the atmosphere of a nearly face-on disk…
The gas temperature structure of protoplanetary disks is a key ingredient for interpreting various disk observations and for quantifying the subsequent evolution of these systems. The comparison of low- and mid-$J$ CO rotational lines is a…
We present deep spectroscopic observations of the classical T Tauri stars DF Tau and V4046 Sgr in order to better characterize two important sources of far-ultraviolet continuum emission in protoplanetary disks. These new Hubble Space…