Search Publications
Resolving the mid-infrared cores of local Seyferts
Vignali, C.; Gilli, R.; Comastri, A. +5 more
We present new photometry of 16 local Seyferts including 6 Compton-thick sources in N-band filters around 12-µm, obtained with the VISIR instrument on the 8-m Very Large Telescope. The near-diffraction-limited imaging provides the least-contaminated core fluxes for these sources to date. Augmenting these with our previous observations and wi…
The dust condensation sequence in red supergiant stars
Eriksson, K.; Hony, S.; Decin, L. +3 more
Context: Red supergiant (RSG) stars exhibit significant mass loss by means of a slow, dense wind. They are often considered to be the more massive counterparts of Asymptotic Giant Branch (AGB) stars. While AGB mass loss is related to their strong pulsations, the RSG are often only weakly variable. This raises the question of whether their wind-dri…
Strong [CII] emission at high redshift
Maiolino, R.; Meneghetti, M.; De Breuck, C. +3 more
We report the detection of the [Cii]157.74 µm fine-structure line in the lensed galaxy BRI 0952-0115 at z=4.43, using the APEX telescope. This is the first detection of the [Cii] line in a source with L_FIR < 1013~L_⊙ at high redshift. The line is much stronger than previous [Cii] detections at high-z (a factor of 5-8 higher in…
A possible architecture of the planetary system HR 8799
Krivov, A. V.; Löhne, T.; Neuhäuser, R. +4 more
HR 8799 is a nearby A-type star with a debris disk and three planetary candidates, which have been imaged directly. We undertake a coherent analysis of various observational data for all known components of the system, including the central star, imaged companions, and dust. Our goal is to elucidate the architecture and evolutionary status of the …
A self-consistent stellar and 3D nebular model of planetary nebula IC 418
Morisset, C.; Georgiev, L.
Aims: We present a coherent stellar and nebular model that reproduces observations of the planetary nebula IC 418. We aim to test whether a stellar model found to provide an optimal description of the stellar observations is able to satisfactory ionize the nebula and reproduce the nebular observations, a finding that is by no mean evident. This al…
Resolved 24.5 micron emission from massive young stellar objects
Onaka, T.; Kataza, H.; Hoare, M. G. +8 more
Context: Massive young stellar objects (MYSO) are surrounded by massive dusty envelopes, whose physical structure and geometry are determined by the star formation process.
Aims: Our principal aim is to establish the density structure of MYSO envelopes on scales of ~1000 AU. This constitutes an increase of a factor ~10 in angular resolution co…
Spatially resolved mid-infrared observations of the triple system T Tauri
Wolf, S.; Ábrahám, P.; Henning, Th. +6 more
Aims: The aim of this study is to enhance our knowledge of the characteristics and distribution of the circumstellar dust associated with the individual components of the young hierarchical triple system T Tau.
Methods: To reach this goal, observations in the N-band (8-13 µm) with the two-telescope interferometric instrument MIDI at the …
A binary engine fuelling HD 87643's complex circumstellar environment. Determined using AMBER/VLTI imaging
Waters, L. B. F. M.; Weigelt, G.; Hofmann, K. -H. +19 more
Context: The star HD 87643, exhibiting the “B[e] phenomenon”, has one of the most extreme infrared excesses for this object class. It harbours a large amount of both hot and cold dust, and is surrounded by an extended reflection nebula.
Aims: One of our major goals was to investigate the presence of a companion in HD87643. In addition, the pre…
EX Lupi in quiescence
Ábrahám, P.; Kóspál, Á.; Kun, M. +5 more
Aims: EX Lupi is the prototype of EXors, a subclass of low-mass pre-main sequence stars whose episodic eruptions are attributed to temporarily increased accretion. In quiescence the optical and near-infrared properties of EX Lup cannot be distinguished from those of normal T Tau stars. Here we investigate whether it is the circumstellar disk struc…
Properties of M31 . I. Dust. Basic properties and a discussion about age-dependent dust heating
Montalto, M.; Seitz, S.; Lee, C. -H. +3 more
Aims: Observations acquired by the Spitzer Space Telescope and improvements to theoretical modeling of dust emission properties are used to discuss the distribution of dust and its characteristics in the closest neighbor spiral galaxy