Search Publications
The emission-line regions in the nucleus of NGC 1313 probed with GMOS-IFU: a supergiant/hypergiant candidate and a kinematically cold nucleus
Steiner, J. E.; Menezes, R. B.
NGC 1313 is a bulgeless nearby galaxy, classified as SB(s)d. Its proximity allows high spatial resolution observations. We performed the first detailed analysis of the emission-line properties in the nuclear region of NGC 1313, using an optical data cube obtained with the Gemini Multi-object Spectrograph. We detected four main emitting areas, thre…
Testing models of quasar hosts with strong gravitational lensing by quasar hosts
Cen, Renyue; Safarzadeh, Mohammadtaher
We perform a statistical analysis of strong gravitational lensing by quasar hosts of background galaxies, in the two competing models of dark matter haloes of quasars, halo occupation distribution (HOD) and Cen and Safarzadeh (CS) models. Utilizing the BolshoiP simulation, we demonstrate that strong gravitational lensing provides a potentially ver…
SXP 7.92: a recently rediscovered Be/X-ray binary in the Small Magellanic Cloud, viewed edge on
D'Elia, V.; Udalski, A.; Esposito, P. +4 more
We present a detailed optical and X-ray study of the 2013 outburst of the Small Magellanic Cloud Be/X-ray binary SXP 7.92, as well as an overview of the last 18 years of observations from OGLE (Optical Gravitational Lensing Experiment), RXTE, Chandra and XMM-Newton. We revise the position of this source to RA(J2000) = 00:57:58.4, Dec(J2000) = -72:…
ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies
Ivison, R. J.; Cooray, A.; Ibar, E. +9 more
Observations using the 7-mm receiver system on the Australia Telescope Compact Array have revealed large reservoirs of molecular gas in two high-redshift radio galaxies: HATLAS J090426.9+015448 (z = 2.37) and HATLAS J140930.4+003803 (z = 2.04). Optically, the targets are very faint, and spectroscopy classifies them as narrow-line radio galaxies. I…
Characterization of the warm-hot intergalactic medium near the Coma cluster through high-resolution spectroscopy of X Comae
Bonamente, M.; Morandi, A.; Tempel, E. +2 more
We have analysed all available archival XMM-Newton observations of X Comae, a bright X-ray quasar behind the Coma cluster, to study the properties of the warm-hot intergalactic medium (WHIM) in the vicinity of the nearest massive galaxy cluster. The reflection grating spectrometer observations confirm the possible presence of a Ne ix K α absorptio…
Cosmic microwave background science at commercial airline altitudes
Peiris, Hiranya V.; Verde, Licia; Feeney, Stephen M. +2 more
Obtaining high-sensitivity measurements of degree-scale cosmic microwave background (CMB) polarization is the most direct path to detecting primordial gravitational waves. Robustly recovering any primordial signal from the dominant foreground emission will require high-fidelity observations at multiple frequencies, with excellent control of system…
Evidence for coherent spicule oscillations from correcting Hinode/SOT Ca II H in the south-east limb of the Sun
Ahangarzadeh Maralani, A. R.; Tavabi, E.; Ajabshirizadeh, A.
Wave theories of heating of the chromosphere, corona and solar wind due to photospheric fluctuations are strengthened by the existence of the wave coherency observed up to the transition region. The coherency of intensity oscillations of solar spicules was explored using the Solar Optical Telescope (SOT) on the Hinode spacecraft with increasing he…
Estimating the chromospheric magnetic field from a revised NLTE modelling: the case of HR 7428
Giarrusso, M.; Leone, F.; Frasca, A. +6 more
In this work, we use the semi-empirical atmospheric modelling method to obtain the chromospheric temperature, pressure, density and magnetic field distribution versus height in the K2 primary component of the RS CVn binary system HR 7428. While temperature, pressure and density are the standard output of the semi-empirical modelling technique, the…
High-resolution spectral analysis of unevenly spaced data using a regularization approach
Seghouani, N.
The problem of estimating the power spectrum of unevenly spaced time series is considered. Indeed, this problem is quite common in ground-based astronomy, and the use of classical methods leads to aliased frequency detection. Moreover, the spectral resolution is limited by the observation time (Shannon-Nyquist law). We propose a regularized method…
Compton thick absorber in type 1 quasar 3C 345 revealed by Suzaku and Swift/BAT
Eguchi, Satoshi
The archival data of 3C 345, a type 1 quasar at z = 0.5928, obtained with Suzaku and Swift/BAT are analysed. Though previous studies of this source applied only a simple broken power-law model, a heavily obscuring material is found to be required by considering Akaike information criteria. The application of the numerical torus model by Murphy &am…