Search Publications
Consistent Dust and Gas Models for Protoplanetary Disks. III. Models for Selected Objects from the FP7 DIANA Project
Waters, L. B. F. M.; Pinte, C.; Woitke, P. +17 more
The European FP7 project DIANA has performed a coherent analysis of a large set of observational data of protoplanetary disks by means of thermo-chemical disk models. The collected data include extinction-corrected stellar UV and X-ray input spectra (as seen by the disk), photometric fluxes, low and high resolution spectra, interferometric data, e…
New evidence for the ubiquity of prominent polar dust emission in AGN on tens of parsec scales
Asmus, D.
The key ingredient of active galactic nuclei (AGN) unification, the dusty obscuring torus was so far held responsible for the observed mid-infrared (MIR) emission of AGN. However, the best studied objects with Very Large Telescope Interferometer (VLTI)/MID-infrared Interferometric instrument (MIDI) show that instead a polar dusty wind is dominatin…
Probable detection of hydrogen sulphide (H2S) in Neptune's atmosphere
Fletcher, Leigh N.; Bézard, Bruno; Irwin, Patrick G. J. +4 more
Recent analysis of Gemini-North/NIFS H-band (1.45-1.8 µm) observations of Uranus, recorded in 2010, with recently updated line data has revealed the spectral signature of hydrogen sulphide (H2S) in Uranus's atmosphere (Irwin et al., 2018). Here, we extend this analysis to Gemini-North/NIFS observations of Neptune recorded in 2009 …
The spectral energy distributions of active galactic nuclei
Salvato, M.; Ricci, C.; Brown, M. J. I. +5 more
We present spectral energy distributions (SEDs) of 41 active galactic nuclei, derived from multiwavelength photometry and archival spectroscopy. All of the SEDs span at least 0.09 to 30 µm, but in some instances wavelength coverage extends into the X-ray, far-infrared, and radio. For some active galactic nuclei (AGNs) we have fitted the meas…
Study of CS, SiO, and SiS abundances in carbon star envelopes: assessing their role as gas-phase precursors of dust
Cernicharo, J.; Agúndez, M.; Massalkhi, S.
Aims: We aim to determine the abundances of CS, SiO, and SiS in a large sample of carbon star envelopes covering a wide range of mass loss rates to investigate the potential role that these molecules could play in the formation of dust in the surroundings of the central AGB star.
Methods: We surveyed a sample of 25 carbon-rich AGB stars …
Consistent dust and gas models for protoplanetary disks. IV. A panchromatic view of protoplanetary disks
Waters, L. B. F. M.; Pinte, C.; Ménard, F. +17 more
Context. Consistent modeling of protoplanetary disks requires the simultaneous solution of both continuum and line radiative transfer, heating and cooling balance between dust and gas and, of course, chemistry. Such models depend on panchromatic observations that can provide a complete description of the physical and chemical properties and energy…
Probing ISM Structure in Trumpler 14 and Carina I Using the Stratospheric Terahertz Observatory 2
van der Tak, Floris F. S.; Tolls, Volker; Horiuchi, Shinji +26 more
We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2. The Trumpler 14/Carina I region is in the western part of the Carina Nebula Complex (CNC), which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 µm transition of…
Examining the Class B to A Shift of the 7.7 µm PAH Band with the NASA Ames PAH IR Spectroscopic Database
Boersma, Christiaan; Shannon, Matthew J.
We present insights into the behavior of the astronomical 7.7 µm polycyclic aromatic hydrocarbon (PAH) emission complex as gleaned from analyzing synthesized spectra, utilizing the data and tools from the NASA Ames PAH IR Spectroscopic Database. We specifically study the influence of PAH size, charge, aliphatic content, and nitrogen substitu…
HD 101584: circumstellar characteristics and evolutionary status
Lindqvist, M.; Olofsson, H.; Bergman, P. +8 more
Context. There is growing evidence that red giant evolution is often affected by an interplay with a nearby companion, in some cases taking the form of a common-envelope evolution.
Aims: We have performed a study of the characteristics of the circumstellar environment of the binary object HD 101584, that provides information on a likely evolu…
Exploring the innermost dust formation region of the oxygen-rich AGB star IK Tauri with VLT/SPHERE-ZIMPOL and VLTI/AMBER
Ohnaka, K.; Adam, C.
Context. Low- and intermediate-mass stars on the asymptotic giant branch (AGB) are known to be prevalent dust providers to galaxies, replenishing the surrounding medium with molecules and dust grains. However, the mechanisms responsible for the formation and acceleration of dust in the cool extended atmospheres of AGB stars are still open to debat…