Search Publications
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…
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…
Interplay between pulsation, mass loss, and third dredge-up: More about Miras with and without technetium
Bernhard, K.; Cristallo, S.; McDonald, I. +2 more
Context. We follow-up on a previous finding that AGB Mira variables containing the third dredge-up indicator technetium (Tc) in their atmosphere form a different sequence of K - [22] colour as a function of pulsation period than Miras without Tc. A near- to mid-infrared colour such as K - [22] is a good probe for the dust mass-loss rate of the sta…
Learning mid-IR emission spectra of polycyclic aromatic hydrocarbon populations from observations
Joblin, C.; Berné, O.; Foschino, S.
Context. The James Webb Space Telescope (JWST) will deliver an unprecedented quantity of high-quality spectral data over the 0.6-28 µm range. It will combine sensitivity, spectral resolution, and spatial resolution. Specific tools are required to provide efficient scientific analysis of such large data sets.
Aims: Our aim is to illustra…
Mid-infrared evolution of η Carinae from 1968 to 2018
Gull, T. R.; Hillier, D. J.; Asmus, D. +6 more
η Car is one of the most luminous and massive stars in our Galaxy and is the brightest mid-IR source in the sky outside our solar system. Since the late 1990s, the central source has dramatically brightened at UV and optical wavelengths. This might be explained by a decrease in circumstellar dust extinction. We aim to establish the mid-IR flux evo…
Origin of hydrogen fluoride emission in the Orion Bar. An excellent tracer for CO-dark H2 gas clouds
Shipman, R. F.; van der Tak, F. F. S.; Tielens, A. G. G. M. +1 more
Context. The hydrogen fluoride (HF) molecule is seen in absorption in the interstellar medium (ISM) along many lines of sight. Surprisingly, it is observed in emission toward the Orion Bar, which is an interface between the ionized region around the Orion Trapezium stars and the Orion molecular cloud.
Aims: We aim to understand the origin of …
30-micron sources in galaxies with different metallicities
Szczerba, R.; Lagadec, E.; Volk, K. +2 more
Aims: We present an analysis and comparison of the 30 µm dust features seen in the Spitzer Space Telescope spectra of 207 carbon-rich asymptotic giant branch (AGB) stars, post-AGB objects, and planetary nebulae (PNe) located in the Milky Way, the Magellanic Clouds (MCs), or the Sagittarius dwarf spheroidal galaxy (Sgr dSph), which are c…
Spatially resolving the atmosphere of the non-Mira-type AGB star SW Vir in near-infrared molecular and atomic lines with VLTI/AMBER
Ohnaka, K.; Hadjara, M.; Maluenda Berna, M. Y. L.
Aims: We present a near-infrared spectro-interferometric observation of the non-Mira-type, semiregular asymptotic giant branch star SW Vir. Our aim is to probe the physical properties of the outer atmosphere with spatially resolved data in individual molecular and atomic lines.
Methods: We observed SW Vir in the spectral window between 2…