Search Publications
Seasonal evolution of C2N2, C3H4, and C4H2 abundances in Titan's lower stratosphere
Irwin, P. G. J.; Teanby, N. A.; Lebonnois, S. +2 more
Aims: We study the seasonal evolution of Titan's lower stratosphere (around 15 mbar) in order to better understand the atmospheric dynamics and chemistry in this part of the atmosphere.
Methods: We analysed Cassini/CIRS far-IR observations from 2006 to 2016 in order to measure the seasonal variations of three photochemical by-products: C…
Deep XMM-Newton observations of the northern disc of M 31. I. Source catalogue
Williams, Benjamin F.; Sasaki, Manami; Haberl, Frank +12 more
Context. We carried out new observations of two fields in the star-forming northern ring of M 31 with XMM-Newton with each one of them consisting of two exposures of about 100 ks each. A previous XMM-Newton survey of the entire M 31 galaxy revealed extended diffuse X-ray emission in these regions.
Aims: We study the population of X-ray source…
ATHOS: On-the-fly stellar parameter determination of FGK stars based on flux ratios from optical spectra
Grebel, Eva K.; Hanke, Michael; Koch, Andreas +1 more
The rapidly increasing number of stellar spectra obtained by existing and future large-scale spectroscopic surveys feeds a demand for fast and efficient tools for the spectroscopic determination of fundamental stellar parameters. Such tools should not only comprise customized solutions for one particular survey or instrument, but, in order to enab…
Twenty years of photometric microlensing events predicted by Gaia DR2. Potential planet-hosting lenses within 100 pc
Lindegren, Lennart; Mustill, Alexander J.; Davies, Melvyn B.
Context. Gaia Data Release 2 (DR2) offers unparalleled precision on stars' parallaxes and proper motions. This allows the prediction of microlensing events for which the lens stars (and any planets they possess) are nearby and may be well studied and characterised.
Aims: We identify a number of potential microlensing events that will occur be…
Color gradients reflect an inside-out growth in early-type galaxies of the cluster MACS J1206.2-0847
Ziegler, B.; Verdugo, M.; Kuchner, U. +1 more
Aims: Color gradients of galaxies are a powerful tool for resolving the variations of stellar populations within galaxies. We use this approach to explore the evolution of early-type galaxies in the core of the massive galaxy cluster MACS J1206.2-0847 at z = 0.44.
Methods: We used imaging data in 12 filters (covering a wavelength range f…
Spectral evolution of the supergiant HMXB IGR J16320-4751 along its orbit using XMM-Newton
García, Federico; Fogantini, Federico A.; Chaty, Sylvain +1 more
Context. The INTEGRAL satellite has revealed a previously hidden population of absorbed high-mass X-ray binaries (HMXBs) hosting supergiant stars. Among them, IGR J16320-4751 is a classical system intrinsically obscured by its environment, with a column density of ∼1023 cm-2, more than an order of magnitude higher than the in…
Generalised model-independent characterisation of strong gravitational lenses. III. Perturbed axisymmetric lenses
Wagner, J.
In galaxy-galaxy strong gravitational lensing, Einstein rings are generated when the lensing galaxy has an axisymmetric lensing potential and the source galaxy is aligned with its symmetry centre along the line of sight. Using a Taylor expansion around the Einstein radius and eliminating the unknown source, I derive a set of analytic equations tha…
Diffuse interstellar bands in the H II region M17. Insights into their relation with the total-to-selective visual extinction RV
Kaper, L.; de Koter, A.; Cox, N. L. J. +1 more
Context. Diffuse interstellar bands (DIBs) are broad absorption features measured in sightlines probing the diffuse interstellar medium. Although large carbon-bearing molecules have been proposed as the carriers producing DIBs, their identity remains unknown. DIBs make an important contribution to the extinction curve; the sightline to the young m…
Circumstellar ammonia in oxygen-rich evolved stars
Menten, K. M.; Greathouse, T. K.; Wyrowski, F. +3 more
Context. The circumstellar ammonia (NH3) chemistry in evolved stars is poorly understood. Previous observations and modelling showed that NH3 abundance in oxygen-rich stars is several orders of magnitude above that predicted by equilibrium chemistry.
Aims: We would like to characterise the spatial distribution and excita…
SPHERE view of Wolf-Rayet 104. Direct detection of the Pinwheel and the link with the nearby star
Avenhaus, H.; Matter, A.; Lopez, B. +16 more
Context. WR104 is an emblematic dusty Wolf-Rayet star and the prototypical member of a sub-group hosting spirals that are mainly observable with high-angular resolution techniques. Previous aperture masking observations showed that WR104 is likely to be an interacting binary star at the end of its life. However, several aspects of the system are s…