Search Publications
Critical study of the distribution of rotational velocities of Be stars. I. Deconvolution methods, effects due to gravity darkening, macroturbulence, and binarity
Cidale, L.; Frémat, Y.; Royer, F. +9 more
Context. Among intermediate-mass and massive stars, Be stars are the fastest rotators in the main sequence (MS) and, as such, these stars are a cornerstone to validate models of structure and evolution of rotating stars. Several phenomena, however, induce under- or overestimations either of their apparent Vsini, or true velocity V.
Aims: In t…
The abundance and thermal history of water ice in the disk surrounding HD 142527 from the DIGIT Herschel Key Program
Waters, L. B. F. M.; Woitke, P.; Hony, S. +9 more
Context. The presence or absence of ice in protoplanetary disks is of great importance to the formation of planets. By enhancing solid surface density and increasing sticking efficiency, ice catalyzes the rapid formation of planetesimals and decreases the timescale of giant planet core accretion.
Aims: In this paper, we analyze the compositio…
The ALMA detection of CO rotational line emission in AGB stars in the Large Magellanic Cloud
van Loon, J. Th.; Olofsson, H.; Sahai, R. +21 more
Context. Low- and intermediate-mass stars lose most of their stellar mass at the end of their lives on the asymptotic giant branch (AGB). Determining gas and dust mass-loss rates (MLRs) is important in quantifying the contribution of evolved stars to the enrichment of the interstellar medium.
Aims: This study attempts to spectrally resolve CO…
The long-wavelength thermal emission of the Pluto-Charon system from Herschel observations. Evidence for emissivity effects
Fornasier, S.; Lellouch, E.; Panuzzo, P. +9 more
Thermal observations of the Pluto-Charon system acquired by the Herschel Space Observatory in February 2012 are presented. They consist of photometric measurements with the PACS and SPIRE instruments (nine visits to the Pluto system each), covering six wavelengths from 70 to 500 µm altogether. The thermal light curve of Pluto-Charon is obser…
Constraints on the H2O formation mechanism in the wind of carbon-rich AGB stars
Blommaert, J. A. D. L.; De Ridder, J.; de Koter, A. +13 more
Context. The recent detection of warm H2O vapor emission from the outflows of carbon-rich asymptotic giant branch (AGB) stars challenges the current understanding of circumstellar chemistry. Two mechanisms have been invoked to explain warm H2O vapor formation. In the first, periodic shocks passing through the medium immediate…
Herschel/HIFI observations of the circumstellar ammonia lines in IRC+10216
Menten, K. M.; Olofsson, H.; Marston, A. P. +14 more
Context. A discrepancy exists between the abundance of ammonia (NH3) derived previously for the circumstellar envelope (CSE) of
Aims: To address the discrepancy described above…
DR Tauri: Temporal variability of the brightness distribution in the potential planet-forming region
Wolf, S.; Ratzka, Th.; Brunngräber, R. +1 more
Aims: We investigate the variability of the brightness distribution and the changing density structure of the protoplanetary disk around DR Tau, a classical T Tauri star. DR Tau is known for its peculiar variations from the ultraviolet (UV) to the mid-infrared (MIR). Our goal is to constrain the temporal variation of the disk structure based …
A low-luminosity type-1 QSO sample . IV. Molecular gas contents and conditions of star formation in three nearby Seyfert galaxies
Eckart, Andreas; Moser, Lydia; Krips, Melanie +8 more
We present a pilot study of ~3'' resolution observations of low CO transitions with the Submillimeter Array in three nearby Seyfert galaxies, which are part of the low-luminosity quasi-stellar object (LLQSOs) sample consisting of 99 nearby (z = 0.06) type-1 active galactic nuclei (AGN) taken from the Hamburg/ESO quasi-stellar object (QSO) survey. …