Related papers: Unlocking CO Depletion in Protoplanetary Disks I. …
MIR spectra imply considerable chemical diversity in the inner regions of protoplanetary discs: some are H2O-dominated, others by CO2. Sublimating ices from radially drifting dust grains are often invoked to explain some of this diversity,…
The Earth and other rocky bodies in the inner solar system contain significantly less carbon than the primordial materials that seeded their formation. These carbon-poor objects include the parent bodies of primitive meteorites, suggesting…
CO isotopes are able to probe the different components in protostellar clouds. These components, core, envelope and outflow have distinct physical conditions and sometimes more than one component contributes to the observed line profile. In…
Observations of CO+ suggest column densities on the order 10^12 cm^-2 that can not be reproduced by many chemical models. CO+ is more likely to be destroyed than excited in collisions with hydrogen. An anomalous excitation mechanism may…
The oxygen isotope fractionation scenario, which has been developed to explain the oxygen isotope anomaly in the solar system materials, predicts that CO gas is depleted in 18O in protoplanetary disks, where segregation between solids and…
Aims: Ices in dense star-forming cores contain the bulk of volatile molecules apart from H2 and thus represent a large fraction of dark cloud chemistry budget.To directly constrain the freeze-out profile of CO, the formation route of CO2…
The relative abundances of atomic and molecular species in planet-forming disks around young stars provide important constraints on photochemical disk models and provide a baseline for calculating disk masses from measurements of trace…
(Abridged) Exoplanet atmospheres are thought be built up from accretion of gas as well as pebbles and planetesimals in the midplanes of planet-forming disks. The chemical composition of this material is usually assumed to be unchanged…
Ices are an important constituent of protoplanetary disks. New observational facilities, notably the James Webb Space Telescope (JWST), will greatly enhance our view of disk ices by measuring their infrared spectral features. We present a…
The bulk composition of the Earth is dramatically carbon poor compared to that of the interstellar medium, and this phenomenon extends to the asteroid belt. To interpret this carbon deficit problem, the carbonaceous component in grains must…
We use the moving mesh code AREPO coupled to a time-dependent chemical network to investigate the formation and destruction of molecular gas in simulated spiral galaxies. This allows us to determine the characteristics of the gas that is…
The most usual tracer of molecular gas is line emission from CO. However, the reliability of that tracer has long been questioned in environments different from the Milky Way. We study the relationship between H2 and CO abundances using a…
Observations of protoplanetary disks suggest that the gas and dust follow significantly different radial distributions. This finding can be theoretically explained by a combination of radial drift and gas drag of intermediate-sized dust…
The chemistry of the diffuse interstellar medium is driven by the combined influences of cosmic rays, ultraviolet (UV) radiation, and turbulence. Previously detected at the outer edges of photodissociation regions (PDRs) and formed from the…
We study the relationship between molecular gas and dust in the California Molecular Cloud over an unprecedented dynamic range of cloud depth (Av = 3 - 60 magnitudes). We compare deep Herschel-based measurements of dust extinction with…
As the sample of mid-inclination disks with measured CO emission surfaces grows, a fundamental unanswered question is how these vertical profiles connect to their host properties. This project aims to relate the vertical extent of…
Accurate measurements of the physical structure of protoplanetary discs are critical inputs for planet formation models. These constraints are traditionally established via complex modelling of continuum and line observations. Instead, we…
Despite being $>10$Myr, there are $\sim$10 debris discs with as much CO gas as in protoplanetary discs. Such discs have been assumed to be "hybrid", i.e., with secondary dust but primordial gas. Here we show that both the dust and gas in…
Characterizing the dust thermal structure in protoplanetary disks is a fundamental task as the dust surface temperature can affect both the planetary formation and the chemical evolution. Since the temperature is dependent on many…
According to the current paradigm of circumstellar disk evolution, gas-rich primordial disks evolve into gas-poor debris disks compose of second-generation dust. To explore the transition between these phases, we searched for $^{12}$CO,…