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We present a new velocity-resolved survey of 2.9 $mu$m spectra of hot H$_2$O and OH gas emission from protoplanetary disks, obtained with CRIRES at the VLT ($Delta v sim$ 3 km s$^{-1}$). With the addition of archival Spitzer-IRS spectra, this is the most comprehensive spectral dataset of water vapor emission from disks ever assembled. We provide line fluxes at 2.9-33 $mu$m that probe from disk radii of $sim0.05$ au out to the region across the water snow line. With a combined dataset for 55 disks, we find a new correlation between H$_2$O line fluxes and the radius of CO gas emission as measured in velocity-resolved 4.7 $mu$m spectra (R$_{rm co}$), which probes molecular gaps in inner disks. We find that H$_2$O emission disappears from 2.9 $mu$m (hotter water) to 33 $mu$m (colder water) as R$_{rm co}$ increases and expands out to the snow line radius. These results suggest that the infrared water spectrum is a tracer of inside-out water depletion within the snow line. It also helps clarifying an unsolved discrepancy between water observations and models, by finding that disks around stars of M$_{star}>1.5$ M$_odot$ generally have inner gaps with depleted molecular gas content. We measure radial trends in H$_2$O, OH, and CO line fluxes that can be used as benchmarks for models to study the chemical composition and evolution of planet-forming disk regions at 0.05-20 au. We propose that JWST spectroscopy of molecular gas may be used as a probe of inner disk gas depletion, complementary to the larger gaps and holes detected by direct imaging and by ALMA.
Transition discs are expected to be a natural outcome of the interplay between photoevaporation (PE) and giant planet formation. Massive planets reduce the inflow of material from the outer to the inner disc, therefore triggering an earlier onset of
The planetary building blocks that formed in the terrestrial planet region were likely very dry, yet water is comparatively abundant on Earth. We review the various mechanisms proposed for the origin of water on the terrestrial planets. Various in-si
Advances in infrared and submillimeter technology have allowed for detailed observations of the molecular content of the planet-forming regions of protoplanetary disks. In particular, disks around solar-type stars now have growing molecular inventori
(Abridged) Near- to mid-IR observations of protoplanetary disks show that the inner regions (<10AU) are rich in small organic volatiles (e.g., C2H2 and HCN). Trends in the data suggest that disks around cooler stars (~3000K) are potentially more carb
We present high resolution (R = 100,000) L-band spectroscopy of 11 Herbig AeBe stars with circumstellar disks. The observations were obtained with the VLT/CRIRES to detect hot water and hydroxyl radical emission lines previously detected in disks aro