Search Publications
Multiple nitrogen reservoirs in a protoplanetary disk at the epoch of comet and giant planet formation
Forveille, T.; Hily-Blant, P.; Magalhaes de Souza, V. +1 more
The isotopic ratio of nitrogen measured in primitive Solar System bodies shows a broad range of values, the origin of which remains unknown. One key question is whether these isotopic reservoirs of nitrogen predate the comet formation stage or are posterior to it. Another central question is elucidating the processes that can produce the observed …
Molecular ion abundances in the diffuse ISM: CF+, HCO+, HOC+, and C3H+
Godard, B.; Roueff, E.; Gerin, M. +4 more
Aims: The transition between atomic and molecular hydrogen is associated with important changes in the structure of interstellar clouds, and marks the beginning of interstellar chemistry. Most molecular ions are rapidly formed (in ion-molecule reactions) and destroyed (by dissociative recombination) in the diffuse ISM. Because of the relative…
Rest-frame far-ultraviolet to far-infrared view of Lyman break galaxies at z = 3: Templates and dust attenuation
Ilbert, O.; Buat, V.; Burgarella, D. +2 more
Aims: This work explores, from a statistical point of view, the rest-frame far-ultraviolet (FUV) to far-infrared (FIR) emission of a population of Lyman-break galaxies (LBGs) at z ∼ 3 that cannot be individually detected from current FIR observations.
Methods: We performed a stacking analysis over a sample of ∼17 000 LBGs at redshift 2.5…
Late-time observations of the extraordinary Type II supernova iPTF14hls
Cenko, S. B.; Sollerman, J.; Gal-Yam, A. +22 more
Aims: We study iPTF14hls, a luminous and extraordinary long-lived Type II supernova, which lately has attracted much attention and disparate interpretation.
Methods: We have presented new optical photometry that extends the light curves up to more than three years past discovery. We also obtained optical spectroscopy over this period, an…
Photospheric magnetic structure of coronal holes
Temmer, Manuela; Veronig, Astrid; Hofmeister, Stefan J. +2 more
In this study, we investigate in detail the photospheric magnetic structure of 98 coronal holes using line-of-sight magnetograms of SDO/HMI, and for a subset of 42 coronal holes using HINODE/SOT G-band filtergrams. We divided the magnetic field maps into magnetic elements and quiet coronal hole regions by applying a threshold at ±25 G. We find tha…
Abundances of disk and bulge giants from high-resolution optical spectra. IV. Zr, La, Ce, Eu
Ryde, N.; Jönsson, H.; Matteucci, F. +1 more
Context. Observations of the Galactic bulge suggest that the disk formed through secular evolution rather than gas dissipation and/or mergers, as previously believed. This would imply very similar chemistry in the disk and bulge. Some elements, such as the α-elements, are well studied in the bulge, but others like the neutron-capture elements are …
Modelling depletion by re-accretion of gas from a dusty disc in post-AGB stars
Van Winckel, Hans; Nelemans, Gijs; Pols, Onno +1 more
Many disc-type post-asymptotic giant branch (post-AGB) stars are chemically peculiar, showing underabundances of refractory elements in their photospheres that correlate with condensation temperature. The aim of this paper is to investigate how accretion from a circumbinary disc can cause this phenomenon of depletion and how this impacts the evolu…
Extended stellar systems in the solar neighborhood. III. Like ships in the night: the Coma Berenices neighbor moving group
Meingast, Stefan; Alves, João; Fürnkranz, Verena
We report the discovery of a kinematically cold group of stars, located in the immediate neighborhood of the well-known star cluster Coma Berenices (Mel 111). The new group identified in tangential velocity space as measured by Gaia contains at least 177 coeval members distributed in two subgroups, and appears as a flattened structure parallel to …
The transitional gap transient AT 2018hso: new insights into the luminous red nova phenomenon
Gromadzki, M.; Mason, E.; Cappellaro, E. +20 more
Context. The absolute magnitudes of luminous red novae (LRNe) are intermediate between those of novae and supernovae (SNe), and show a relatively homogeneous spectro-photometric evolution. Although they were thought to derive from core instabilities in single stars, there is growing support for the idea that they are triggered by binary interactio…
Hot, rocky and warm, puffy super-Earths orbiting TOI-402 (HD 15337)
Latham, David W.; Ricker, George R.; Seager, Sara +30 more
Context. The Transiting Exoplanet Survey Satellite (TESS) is revolutionising the search for planets orbiting bright and nearby stars. In sectors 3 and 4, TESS observed TOI-402 (TIC-120896927), a bright V = 9.1 K1 dwarf also known as HD 15337, and found two transiting signals with periods of 4.76 and 17.18 days and radii of 1.90 and 2.21 R⊕