Search Publications
Dissecting bombs and bursts: non-LTE inversions of low-atmosphere reconnection in SST and IRIS observations
Carlsson, M.; Rouppe van der Voort, L. H. M.; de la Cruz Rodríguez, J. +3 more
Ellerman bombs and UV bursts are transient brightenings that are ubiquitously observed in the lower atmospheres of active and emerging flux regions. As they are believed to pinpoint sites of magnetic reconnection in reconfiguring fields, understanding their occurrence and detailed evolution may provide useful insight into the overall evolution of …
Swift UVOT near-UV transit observations of WASP-121 b
Schmitt, J. H. M. M.; Czesla, S.; Salz, M. +3 more
Close-in gas planets are subject to continuous photoevaporation that can erode their volatile envelopes. Today, ongoing mass loss has been confirmed in a few individual systems via transit observations in the ultraviolet spectral range. We demonstrate that the Ultraviolet/Optical Telescope (UVOT) onboard the Neil Gehrels Swift Observatory enables …
The EBLM Project. V. Physical properties of ten fully convective, very-low-mass stars
Smalley, Barry; Hellier, Coel; Triaud, Amaury H. M. J. +28 more
Measurements of the physical properties of stars at the lower end of the main sequence are scarce. In this context we report masses, radii and surface gravities of ten very-low-mass stars in eclipsing binary systems, with orbital periods of the order of several days. The objects probe the stellar mass-radius relation in the fully convective regime…
SPHERE view of the jet and the envelope of RY Tauri
Ménard, F.; Fantinel, D.; Podio, L. +40 more
Context. Jets are rarely associated with pre-main sequence intermediate-mass stars. This contrasts with the frequent detection of jets in lower mass or younger stars. Optical and near-IR observations of jet-driving sources are often hindered by the presence of a natal envelope.
Aims: Jets around partly embedded sources are a useful diagnostic…
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 …