Search Publications
Simultaneous optical/X-ray study of GS 1354-64 (=BW Cir) during hard outburst: evidence for optical cyclo-synchrotron emission from the hot accretion flow
Gandhi, Poshak; Altamirano, Diego; Misra, Ranjeev +3 more
We present results from simultaneous optical [South African Large Telescope (SALT)] and X-ray (Swift and INTEGRAL) observations of GS 1354-64/BW Cir during the 2015 hard state outburst. During the rising phase, optical/X-ray time series shows a strong anti-correlation with X-ray photons lagging optical. Optical and X-ray power spectra show quasi-p…
Soft extragalactic X-ray binaries at the Eddington Threshold
Roberts, Timothy P.; Earnshaw, Hannah M.
The luminosity range at and just below the 1039 erg s-1 cut-off for defining ultraluminous X-ray sources (ULXs) is a little-explored regime. It none the less hosts a large number of X-ray sources, and has great potential for improving our understanding of sources with ∼Eddington accretion rates. We select a sample of four sou…
A 3D model for carbon monoxide molecular line emission as a potential cosmic microwave background polarization contaminant
Baccigalupi, C.; Fabbian, G.; Puglisi, G.
We present a model for simulating carbon monoxide (CO) rotational line emission in molecular clouds, taking account of their 3D spatial distribution in galaxies with different geometrical properties. The model implemented is based on recent results in the literature and has been designed for performing Monte Carlo (MC) simulations of this emission…
The SAMI Galaxy Survey: kinematics of dusty early-type galaxies
Groves, B. A.; Konstantopoulos, I. S.; Cortese, L. +19 more
Recently, large samples of visually classified early-type galaxies (ETGs) containing dust have been identified using space-based infrared observations with the Herschel Space Telescope. The presence of large quantities of dust in massive ETGs is peculiar as X-ray haloes of these galaxies are expected to destroy dust in ∼107 yr (or less)…
Searching for luminous absorbed sources in the WISE AGN catalogue
Georgantopoulos, I.; Carrera, F. J.; Mountrichas, G. +6 more
Mid-infrared (IR) colour selection techniques have proved to be very efficient in finding active galactic nuclei (AGN). This is because the AGN heats the surrounding dust producing warm mid-IR colours. Using the Wide-field Infrared Survey Explorer 3.6, 4.5 and 12 µm colours, the largest sample of IR selected AGN has already been produced con…
Integrated and resolved dust attenuation in clumpy star-forming galaxies at 0.07 < z < 0.14
Glazebrook, Karl; Obreschkow, Danail; Abraham, Roberto +7 more
Dust attenuation in galaxies has been extensively studied nearby, however, there are still many unknowns regarding attenuation in distant galaxies. We contribute to this effort using observations of star-forming galaxies in the redshift range z = 0.05-0.15 from the DYnamics of Newly Assembled Massive Objects (DYNAMO) survey. Highly star-forming DY…
A minimal empirical model for the cosmic far-infrared background anisotropies
Wu, Hao-Yi; Doré, Olivier
Cosmic far-infrared background (CFIRB) probes unresolved dusty star-forming galaxies across cosmic time and is complementary to ultraviolet and optical observations of galaxy evolution. In this work, we interpret the observed CFIRB anisotropies using an empirical model based on resolved galaxies in ultraviolet and optical surveys. Our model includ…
Magnetic activity and radial velocity filtering of young Suns: the weak-line T-Tauri stars Par 1379 and Par 2244
Carmona, A.; Donati, J. -F.; Bouvier, J. +5 more
We report the results of our spectropolarimetric monitoring of the weak-line T-Tauri stars (wTTSs) Par 1379 and Par 2244, within the MaTYSSE (Magnetic Topologies of Young Stars and the Survival of close-in giant Exoplanets) programme. Both stars are of a similar mass (1.6 and 1.8 M⊙) and age (1.8 and 1.1 Myr), with Par 1379 hosting an e…
Ground-based monitoring of comet 67P/Churyumov-Gerasimenko gas activity throughout the Rosetta mission
Snodgrass, C.; Gillon, M.; Jehin, E. +5 more
Simultaneously to the ESA Rosetta mission, a world-wide ground-based campaign provided measurements of the large scale activity of comet 67P/Churyumov-Gerasimenko through measurement of optically active gas species and imaging of the overall dust coma. We present more than 2 yr of observations performed with the FORS2 low-resolution spectrograph a…
Testing multimass dynamical models of star clusters with real data: mass segregation in three Galactic globular clusters
Dalessandro, E.; Beccari, G.; Pallanca, C. +1 more
We present the results of the analysis of deep photometric data for a sample of three Galactic globular clusters (NGC5466, NGC6218 and NGC 6981) with the aim of estimating their degree of mass segregation and testing the predictions of analytic dynamical models. The adopted data set, composed of both Hubble Space Telescope and ground-based data, r…