Search Publications
The SLUGGS survey*: exploring the globular cluster systems of the Leo II group and their global relationships
Spitler, Lee R.; Forbes, Duncan A.; Romanowsky, Aaron J. +6 more
We present an investigation of the globular cluster (GC) systems of NGC 3607 and NGC 3608 as part of the ongoing SLUGGS (SAGES Legacy Unifying Globulars and GalaxieS) survey. We use wide-field imaging data from the Subaru telescope in the g, r and I filters to analyse the radial density, colour and azimuthal distributions of both GC systems. With …
Galactic Centre hypershell model for the North Polar Spurs
Kataoka, J.; Matsui, H.; Nakashima, S. +5 more
The bipolar-hypershell (BHS) model for the North Polar Spurs (NPS-E, -W, and Loop I) and counter southern spurs (SPS-E and -W) is revisited based on numerical hydrodynamical simulations. Propagations of shock waves produced by energetic explosive events in the Galactic Centre are examined. Distributions of soft X-ray brightness on the sky at 0.25,…
Searching for intermediate-mass black holes in globular clusters with gravitational microlensing
Kains, N.; Bramich, D. M.; Sahu, K. C. +1 more
We discuss the potential of the gravitational microlensing method as a unique tool to detect unambiguous signals caused by intermediate-mass black holes in globular clusters. We select clusters near the line of sight to the Galactic bulge and the Small Magellanic Cloud, estimate the density of background stars for each of them, and carry out simul…
Relativistic Fe Kα line study in Seyfert 1 galaxies observed with Suzaku
Nandra, K.; Ponti, G.; Mantovani, G.
We present an analysis of a sample of Seyfert 1 galaxies observed with Suzaku. The aim of this work is to examine critically the evidence for a relativistic Fe Kα line in the X-ray spectra of these active galactic nuclei. The sample was compiled from those sources in which a relativistic component was missing in at least one XMM-Newton observation…
The variable spin-down rate of the transient magnetar XTE J1810-197
Pintore, Fabio; Mereghetti, Sandro; Esposito, Paolo +7 more
We have analysed XMM-Newton and Chandra observations of the transient magnetar XTE J1810-197 spanning more than 11 yr, from the initial phases of the 2003 outburst to the current quiescent level. We investigated the evolution of the pulsar spin period and we found evidence for two distinct regimes: during the outburst decay, dot{ν } was highly var…
Solo dwarfs I: survey introduction and first results for the Sagittarius dwarf irregular galaxy
Côté, P.; Battaglia, G.; Lewis, G. F. +6 more
We introduce the Solitary Local dwarfs survey (Solo), a wide-field photometric study targeting every isolated dwarf galaxy within 3 Mpc of the Milky Way. Solo is based on (u)gi multiband imaging from Canada-France-Hawaii Telescope/MegaCam for northern targets, and Magellan/Megacam for southern targets. All galaxies fainter than MV ≃ -18…
The column density distribution of hard X-ray radio galaxies
Venturi, T.; Dallacasa, D.; Ubertini, P. +6 more
In order to investigate the role of absorption in active galactic nuclei (AGN) with jets, we have studied the column density distribution of a hard X-ray selected sample of radio galaxies, derived from the INTEGRAL/Imager on Board the Integral Satellite (IBIS) and Swift/The Burst Alert Telescope (BAT) AGN catalogues (∼7-10 per cent of the total AG…
Accurate parameters for HD 209458 and its planet from HST spectrophotometry
del Burgo, C.; Allende Prieto, C.
We present updated parameters for the star HD 209458 and its transiting giant planet. The stellar angular diameter θ = 0.2254 ± 0.0017 mas is obtained from the average ratio between the absolute flux observed with the Hubble Space Telescope and that of the best-fitting Kurucz model atmosphere. This angular diameter represents an improvement in pre…
Spectral and timing evolution of the bright failed outburst of the transient black hole Swift J174510.8-262411
Sbarufatti, B.; Homan, J.; Tomsick, J. A. +13 more
We studied time variability and spectral evolution of the Galactic black hole transient Swift J174510.8-262411 during the first phase of its outburst. INTEGRAL and Swift observations collected from 2012 September 16 until October 30 have been used. The total squared fractional rms values did not drop below 5 per cent and quasi-periodic oscillation…
The X-ray dust-scattered rings of the black hole low-mass binary V404 Cyg
Vasilopoulos, G.; Petropoulou, M.
We report on the first detection of X-ray dust-scattered rings from the Galactic low-mass X-ray binary V404 Cyg. The observation of the system with Swift/XRT on 2015 June 30 revealed the presence of five concentric ring-like structures centred at the position of V404 Cyg. Follow-up Swift/XRT observations allowed a time-dependent study of the X-ray…