Search Publications
Evidence for magnetic activity at starbirth: a powerful X-ray flare from the Class 0 protostar HOPS 383
Hamaguchi, Kenji; Kastner, Joel H.; Principe, David A. +1 more
Context. Class 0 protostars represent the earliest evolutionary stage of solar-type stars, during which the majority of the system mass resides in an infalling envelope of gas and dust and is not yet in the central, nascent star. Although X-rays are a key signature of magnetic activity in more evolved protostars and young stars, whether such magne…
Lyman continuum leakage in faint star-forming galaxies at redshift z = 3-3.5 probed by gamma-ray bursts
Covino, S.; Campana, S.; Salvaterra, R. +23 more
Context. The identification of the sources that reionized the Universe and their specific contribution to this process are key missing pieces of our knowledge of the early Universe. Faint star-forming galaxies may be the main contributors to the ionizing photon budget during the epoch of reionization, but their escaping photons cannot be detected …
The chemical composition of impact craters on Titan. I. Implications for exogenic processing
Drossart, P.; Witasse, O.; Altobelli, N. +12 more
We investigate the spectral behavior of nine Titan impact craters in order to constrain their composition. Past studies that have examined the chemical composition of impact craters on Titan have either used qualitative comparisons between craters or combined all craters into a single unit, rather than separating them by geographic location and/or…
CO-driven activity constrains the origin of comets
Blum, J.; Fulle, M.; Rotundi, A.
Context. An open question in the study of comets is the so-called cohesion bottleneck, that is, how dust particles detach from the nucleus.
Aims: We test whether the CO pressure buildup inside the pebbles of which cometary nuclei consist can overcome this cohesion bottleneck.
Methods: A recently developed pebble-diffusion model was appli…
Galaxy classification: deep learning on the OTELO and COSMOS databases
Bland-Hawthorn, Joss; Gallego, Jesús; Sánchez-Portal, Miguel +19 more
Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution.
Aims: Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared pho…
New ultracool dwarf neighbours within 20 pc from Gaia DR2
Scholz, R. -D.
Aims: The Gaia data release 2 (DR2) contains > 6000 objects with parallaxes (Plx + 3 × e_Plx) > 50 mas, placing them within 20 pc from the Sun. Because the expected numbers based on extrapolating the well-known 10 pc census are much lower, nearby Gaia stars need a quality assessment. The 20 pc sample of white dwarfs (WDs) has been verif…
A hyper luminous starburst at z = 4.72 magnified by a lensing galaxy pair at z = 1.48
Daddi, E.; Elbaz, D.; Ilbert, O. +23 more
We serendipitously discovered in the Herschel Reference Survey an extremely bright infrared source with S500 ∼ 120 mJy in the line of sight of the Virgo cluster which we name Red Virgo 4 (RV4). Based on IRAM/EMIR and IRAM/NOEMA detections of the CO(5-4), CO(4-3), and [CI] lines, RV4 is located at a redshift of 4.724, yielding a total ob…
Updated X-ray view of the Hyades cluster
Schmitt, J. H. M. M.; Robrade, J.; Schneider, P. C. +1 more
Aims: We revisit the X-ray properties of the main sequence Hyades members and the relation between X-ray emission and stellar rotation.
Methods: As an input catalog for Hyades members, we combined three recent Hyades membership lists derived from Gaia DR2 data that include the Hyades core and its tidal tails. We searched for X-ray detect…
Polarisation and source structure of solar stationary type IV radio bursts
Klein, Karl-Ludwig; Salas-Matamoros, Carolina
The reconfiguration of the magnetic field during and after a coronal mass ejection (CME) may be accompanied by radio emission from non-thermal electrons. In particular, stationary type IV bursts (also called storm continua) are emitted by electrons in closed magnetic configurations usually located in the wake of the outward-travelling CME. Althoug…
Geometry of the X-ray source 1H 0707-495
Done, Chris; Mizumoto, Misaki; Szanecki, Michał +3 more
Aims: We investigate the constraints on the size and location of the X-ray source in 1H 0707-495 determined from the shape of the relativistically smeared reflection from the accretion disc.
Methods: We developed a new code to model an extended X-ray source and we applied this code to all archival XMM observations of 1H 0707-495.
Re…