Search Publications
The high-energy gamma-ray detection of G73.9+0.9, a supernova remnant interacting with a molecular cloud
Mikołajewska, Joanna; Chernyakova, Maria; Zdziarski, Andrzej A. +6 more
We have analysed the Fermi Large Area Telescope (LAT) data on the SNR G73.9+0.9. We have confirmed a previous detection of high-energy γ-rays from this source at a high significance of ≃12σ. The observed spectrum shows a significant curvature, peaking in EFE at ∼1 GeV. We have also calculated the flux upper limits in the mm-wavelength a…
Atomic data and density diagnostics for S IV
Del Zanna, G.; Badnell, N. R.
We present a new large-scale R-matrix scattering calculation for S IV. We used the intermediate-coupling frame transformation method and applied term energy corrections. Our calculation has a much larger configuration-interaction and close-coupling expansion than previous calculations. Despite that, we find good agreement in the predicted intensit…
Clues to cometary circular polarization from studying the magnetic field in the vicinity of the nucleus of comet 67P/Churyumov-Gerasimenko
Kolokolova, Ludmilla; Hoang, Thiem; Goetz, Charlotte +4 more
Circular polarization in cometary continuum bands has been observed for more than 30 years. Recently, imaging data on circular polarization have been obtained for more than 10 comets using the 6-m Big Telescope Alt-azimuthal (BTA) telescope (Russia). However, despite the accumulation of significant amounts of data, the mechanisms that form circula…
Spectral variation in the supergiant fast X-ray transient SAX J1818.6-1703 observed by XMM-Newton and INTEGRAL
Hill, A. B.; Sidoli, L.; Bird, A. J. +6 more
We present the results of a 30 ks XMM-Newton observation of the supergiant fast X-ray transient (SFXT) SAX J1818.6-1703 - the first in-depth soft X-ray study of this source around periastron. INTEGRAL observations shortly before and after the XMM-Newton observation show the source to be in an atypically active state. Over the course of the XMM-New…
Constraining SN feedback: a tug of war between reionization and the Milky Way satellites
Lacey, Cedric G.; Hou, Jun; Frenk, Carlos. S. +1 more
Theoretical models of galaxy formation based on the cold dark matter cosmogony typically require strong feedback from supernova (SN) explosions in order to reproduce the Milky Way satellite galaxy luminosity function and the faint end of the field galaxy luminosity function. However, too strong a SN feedback also leads to the universe reionizing t…
High-angular-resolution stellar imaging with occultations from the Cassini spacecraft - III. Mira
Nicholson, Philip D.; Hedman, Matthew M.; Stewart, Paul N. +1 more
We present an analysis of spectral and spatial data of Mira obtained by the Cassini spacecraft, which not only observed the star's spectra over a broad range of near-infrared wavelengths, but was also able to obtain high-resolution spatial information by watching the star pass behind Saturn's rings. The observed spectral range of 1-5 microns revea…
Nuclear discs as clocks for the assembly history of early-type galaxies: the case of NGC 4458
Morelli, L.; Maraston, C.; Corsini, E. M. +6 more
Approximately 20 per cent of early-type galaxies host small nuclear stellar discs that are tens to a few hundred parsecs in size. Such discs are expected to be easily disrupted during major galactic encounters, hence their age serve to constrain their assembly history. We use VIsible MultiObject Spectrograph integral-field spectroscopic observatio…
Analysis of the dust jet imaged by Rosetta VIRTIS-M in the coma of comet 67P/Churyumov-Gerasimenko on 2015 April 12
Bieler, A.; Capaccioni, F.; Combi, M. R. +10 more
This work is a part of a more global effort aimed at understanding and interpreting in situ and remote sensing data acquired by instruments on board Rosetta. This study aims at deriving the dust mass source rate and the location of the dust jet source observed by Rosetta VIRTIS-M on 2015 April 12. The analysis is performed by means of the coupled …
Can we distinguish early dark energy from a cosmological constant?
Shi, Difu; Baugh, Carlton M.
Early dark energy (EDE) models are a class of quintessence dark energy with a dynamically evolving scalar field which display a small but non-negligible amount of dark energy at the epoch of matter-radiation equality. Compared with a cosmological constant, the presence of dark energy at early times changes the cosmic expansion history and conseque…
Diagnosing shock temperature with NH3 and H2O profiles
Codella, C.; Bachiller, R.; Fuente, A. +9 more
In a previous study of the L1157 B1 shocked cavity, a comparison between NH3(10-00) and H2O(110-101) transitions showed a striking difference in the profiles, with H2O emitting at definitely higher velocities. This behaviour was explained as a result of the high-temperatu…