Search Publications
Tidal disruption events from massive black hole binaries: predictions for ongoing and future surveys
Sesana, Alberto; Thorp, Stephen; Chadwick, Eli
We compute the expected cosmic rates of tidal disruption events (TDEs) induced by individual massive black holes (MBHs) and by MBH binaries (MBHBs) - with a specific focus on the latter class - to explore the potential of TDEs to probe the cosmic population of sub-pc MBHBs. Rates are computed by combining MBH and MBHB population models derived fro…
The complex evolution of the X-ray binary transient MAXI J1807+132 along the decay of its discovery outburst
Russell, D. M.; Armas Padilla, M.; Jiménez-Ibarra, F. +6 more
MAXI J1807+132 is an X-ray transient discovered during the decay of an outburst in 2017. We present optical and X-ray monitoring of the source over more than 125 d, from outburst to quiescence. The outburst decay is characterized by the presence of several reflares with a quasi-periodic recurrence time of ∼6.5 d. We detect broad H and He emission …
Quantifying the thermal Sunyaev-Zel'dovich effect and excess millimetre emission in quasar environments
Hilton, Matt; Sifón, Cristóbal; Battaglia, Nicholas +23 more
In this paper, we probe the hot, post-shock gas component of quasar-driven winds through the thermal Sunyaev-Zel'dovich (tSZ) effect. Combining data sets from the Atacama Cosmology Telescope, the Herschel Space Observatory, and the Very Large Array, we measure average spectral energy distributions of 109 829 optically selected, radio quiet quasars…
The effect of tides on the Sculptor dwarf spheroidal galaxy
Iorio, G.; Battaglia, G.; Sollima, A. +1 more
Dwarf spheroidal galaxies (dSphs) appear to be some of the most dark matter (DM)-dominated objects in the Universe. Their dynamical masses are commonly derived using the kinematics of stars under the assumption of equilibrium. However, these objects are satellites of massive galaxies (e.g. the Milky Way) and thus can be influenced by their tidal f…
The behaviour of chemical elements in 62 Am star candidates
Giarrusso, M.; Leone, F.; Busà, I. +3 more
In this paper, we present the results of a spectroscopic campaign devoted to ascertain the actual nature of a sample of 155 objects reported as uncertain peculiar stars in the General catalogue of Ap, Am, and HgMn stars. Spectroscopic observations have been obtained with Catania Astrophysical Observatory Spectropolarimeter. We derive for all the o…
Cooling in the X-ray halo of the rotating, massive early-type galaxy NGC 7049
Simionescu, A.; Gaspari, M.; Sun, M. +9 more
The relative importance of the physical processes shaping the thermodynamics of the hot gas permeating rotating, massive early-type galaxies is expected to be different from that in non-rotating systems. Here, we report the results of the analysis of XMM-Newton data for the massive, lenticular galaxy NGC 7049. The galaxy harbours a dusty disc of c…
The course of the Orphan Stream in the Northern Galactic hemisphere traced with Gaia DR2
van der Marel, Roeland P.; Fardal, Mark A.; Sohn, Sangmo Tony +1 more
The Orphan Stream is one of the most prominent tidal streams in the Galactic halo. Using data on red giants, RR Lyrae, and horizontal branch stars from Gaia and other surveys, we determine the proper motion of the Orphan Stream over a path of more than 90° on the sky. We also provide updated tracks for the sky position, distance, and radial veloci…
Weak lensing measurements of the APEX-SZ galaxy cluster sample
Israel, Holger; Klein, Matthias; Bertoldi, Frank +5 more
We present a weak lensing analysis for galaxy clusters from the APEX-SZ survey. For 39 massive galaxy clusters that were observed via the Sunyaev-Zel'dovich effect (SZE) with the APEX telescope, we analyse deep optical imaging data from WFI(@2.2mMPG/ESO) and Suprime-Cam(@SUBARU) in three bands. The masses obtained in this study, including an X-ray…
On the extraction of the power-law parts of probability density functions in star-forming clouds
Klessen, Ralf S.; Schneider, Nicola; Veltchev, Todor V. +5 more
We present a new approach to extract the power-law part of a density/column-density probability density function (ρ-pdf/N-pdf) in star-forming clouds. This approach is based on the mathematical method BPLFIT of Virkar & Clauset (2014, Annals of Applied Statistics, 8, 89) and it assesses the power-law part of an arbitrary distribution, without …
Powerful AGN jets and unbalanced cooling in the hot atmosphere of IC 4296
Mernier, F.; Fabian, A. C.; Sun, M. +13 more
We present new Karl G. Jansky Very Large Array (VLA, 1.5 GHz) radio data for the giant elliptical galaxy IC 4296, supported by archival radio, X-ray (Chandra, and XMM-Newton) and optical (SOAR, and HST) observations. The galaxy hosts powerful radio jets piercing through the inner hot X-ray emitting atmosphere, depositing most of the energy into th…