Search Publications
Evolution of the ion environment of comet 67P during the Rosetta mission as seen by RPC-ICA
Henri, Pierre; Alho, Markku; Simon Wedlund, Cyril +10 more
Rosetta has followed comet 67P from low activity at more than 3.6 au heliocentric distance to high activity at perihelion (1.24 au) and then out again. We provide a general overview of the evolution of the dynamic ion environment using data from the RPC-ICA ion spectrometer. We discuss where Rosetta was located within the evolving comet magnetosph…
Hot gas around SN 1998bw: Inferring the progenitor from its environment
Galbany, L.; Schady, P.; Krühler, T. +3 more
Spatially resolved spectroscopy of the environments of explosive transients carries detailed information about the physical properties of the stellar population that gave rise to the explosion, and thus the progenitor itself. Here, we present new observations of ESO184-G82, the galaxy hosting the archetype of the γ-ray burst/supernova connection, …
CMB constraints on the inflaton couplings and reheating temperature in α-attractor inflation
Drewes, Marco; Kang, Jin U.; Mun, Ui Ri
We study reheating in α-attractor models of inflation in which the inflaton couples to other scalars or fermions. We show that the parameter space contains viable regions in which the inflaton couplings to radiation can be determined from the properties of CMB temperature fluctuations, in particular the spectral index. This may be the only way to …
Lessons from the Auriga discs: the hunt for the Milky Way's ex situ disc is not yet over
Monachesi, Antonela; Springel, Volker; Grand, Robert J. J. +7 more
We characterize the contribution from accreted material to the galactic discs of the Auriga Project, a set of high-resolution magnetohydrodynamic cosmological simulations of late-type galaxies performed with the moving-mesh code AREPO. Our goal is to explore whether a significant accreted (or ex situ) stellar component in the Milky Way disc could …
2WHSP: A multi-frequency selected catalogue of high energy and very high energy γ-ray blazars and blazar candidates
Giommi, P.; Padovani, P.; Chang, Y. -L. +1 more
Aims: High synchrotron peaked blazars (HSPs) dominate the γ-ray sky at energies higher than a few GeV; however, only a few hundred blazars of this type have been cataloged so far. In this paper we present the 2WHSP sample, the largest and most complete list of HSP blazars available to date, which is an expansion of the 1WHSP catalogue of γ-ra…
VLT/FORS2 comparative transmission spectroscopy II: Confirmation of a cloud deck and Rayleigh scattering in WASP-31b, but no potassium?
Nikolov, Nikolay; Gibson, Neale P.; Sing, David K. +4 more
We present transmission spectroscopy of the hot-Jupiter WASP-31b using the FOcal Reducer and low dispersion Spectrograph 2 (FORS2) on the Very Large Telescope during two primary transits. The observations cover a wavelength range of ≈400-840 nm. The light curves are corrupted by significant systematics, but these were to first-order invariant with…
Microflare Heating of a Solar Active Region Observed with NuSTAR, Hinode/XRT, and SDO/AIA
Krucker, Säm; White, Stephen M.; Grefenstette, Brian W. +7 more
NuSTAR is a highly sensitive focusing hard X-ray (HXR) telescope and has observed several small microflares in its initial solar pointings. In this paper, we present the first joint observation of a microflare with NuSTAR and Hinode/XRT on 2015 April 29 at ∼11:29 UT. This microflare shows the heating of material to several million Kelvin, observed…
Solar Active Region Coronal Jets. II. Triggering and Evolution of Violent Jets
Panesar, Navdeep K.; Moore, Ronald L.; Sterling, Alphonse C. +2 more
We study a series of X-ray-bright, rapidly evolving active region coronal jets outside the leading sunspot of AR 12259, using Hinode/X-ray telescope, Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI), and Interface Region Imaging Spectrograph (IRIS) data. The detailed evolution of such r…
GRB 161219B/SN 2016jca: A low-redshift gamma-ray burst supernova powered by radioactive heating
Covino, S.; Sánchez-Ramírez, R.; D'Elia, V. +22 more
Since the first discovery of a broad-lined type Ic supernova (SN) with a long-duration gamma-ray burst (GRB) in 1998, fewer than fifty GRB-supernovae (SNe) have been discovered. The intermediate-luminosity Swift GRB 161219B and its associated supernova SN 2016jca, which occurred at a redshift of z = 0.1475, represents only the seventh GRB-SN to ha…
First evidence of external disc photoevaporation in a low mass star forming region: the case of IM Lup
Cleeves, L. Ilsedore; Facchini, Stefano; Clarke, Cathie J. +1 more
We model the radiatively driven flow from IM Lup - a large protoplanetary disc expected to be irradiated by only a weak external radiation field (at least 104 times lower than the ultraviolet field irradiating the Orion Nebula Cluster proplyds). We find that material at large radii (>400 au) in this disc is sufficiently weakly gravit…