Related papers: A deep search for H2D+ in protoplanetary disks
The molecular composition inside the dust sublimation zones of protoplanetary disks is mostly unknown but important to understanding terrestrial planet formation. A few molecules have been observed from this region, specifically CO, H2O, OH…
[Abridged] Protoplanetary disks have been studied extensively, both physically and chemically, to understand the environment in which planets form. However, the first steps of planet formation are likely to occur already when the protostar…
The thermal structure of protoplanetary disks is a fundamental characteristic of the system that has wide reaching effects on disk evolution and planet formation. In this study, we constrain the 2D thermal structure of the protoplanetary…
The results of single-dish observations of low- and high-J transitions of selected molecules from protoplanetary disks around two TTauri stars (LkCa15 and TWHya) and two HerbigAe stars (HD163296 and MWC480) are reported. Simple molecules…
The high spatial and line sensitivity of ALMA opens the possibility of resolving emission from molecules in circumstellar disks. With an understanding of physical conditions under which molecules have high abundance, they can be used as…
Carbon monoxide (CO) is the most commonly used tracer of molecular gas in the inner regions of protoplanetary disks. CO can be used to constrain the excitation and structure of the circumstellar environment. Absorption line spectroscopy…
We present a survey of the ortho-H2D+(1_{1,0}-1_{1,1}) line toward a sample of 10 starless cores and 6 protostellar cores, carried out at the Caltech Submillimeter Observatory. The high diagnostic power of this line is revealed for the…
Studying molecular species in protoplanetary disks is very useful to characterize the properties of these objects, which are the site of planet formation. We attempt to constrain the chemistry of S-bearing molecules in the cold parts of…
Prestellar cores represent the initial conditions of star formation, but heavy molecules such as CO are strongly depleted in their cold, dense interiors, limiting the ability to probe core centers. Deuterated molecular ions therefore emerge…
%Context: {Previous studies have indicated that the 372.4 GHz ground transition of ortho-H$_2$D$^+$ might be a powerful probe of Proto-Planetary Disks. The line could be especially suited for study of the disk mid-plane, where the bulk of…
In this Letter we model the chemistry of DCO$^{+}$ in protoplanetary disks. We find that the overall distribution of the DCO$^{+}$ abundance is qualitatively similar to that of CO but is dominated by thin layer located at the inner disk…
We investigate deuterium chemistry coupled with the nuclear spin-state chemistry of H$_2$ and H$_3^+$ in protoplanetary disks. Multiple paths of deuterium fractionation are found; exchange reactions with D atoms, such as HCO$^+$ + D, are…
We predict how protoplanetary disks around low-mass young stars would appear in molecular lines observed with the ALMA interferometer. Our goal is to identify those molecules and transitions that can be used to probe and distinguish between…
Context: In the last years, the H2D+ and D2H+ molecules have gained great attention as probes of cold and depleted dense molecular cloud cores. These ions are at the basis of molecular deuterium fractionation, a common characteristic…
This paper introduces a new disk code, called ProDiMo, to calculate the thermo-chemical structure of protoplanetary disks and to interpret gas emission lines from UV to sub-mm. We combine frequency-dependent 2D dust continuum radiative…
We present Submillimeter Array observations of H2CO and N2H+ emission in the disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296 at 2"-6" resolution and discuss the distribution of these species with respect to CO…
The total gas mass of a protoplanetary disk is a fundamental, but poorly determined, quantity. A new technique \citep{bergin+13} has been demonstrated to assess directly the bulk molecular gas reservoir of molecular hydrogen using the HD…
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…
Observations of submillimeter lines of CO (up to J=6-5), HCO+, HCN (up to J=4-3) and their isotopes from circumstellar disks around low mass pre-main sequence stars are presented. The different line ratios and optical depths indicate that…
We report the first detection of DCO+ in a circumstellar disk. The DCO+ J=5-4 line at 360.169 GHz is observed with the 15m James Clerk Maxwell Telescope in the disk around the pre-main sequence star TW Hya. Together with measurements of the…