Search Publications
Quantitative modelling of type Ia supernovae spectral time series: constraining the explosion physics
Maguire, K.; Ackley, K.; Magee, M. R. +2 more
Multiple explosion mechanisms have been proposed to explain type Ia supernovae (SNe Ia). Empirical modelling tools have also been developed that allow for fast, customized modelling of individual SNe and direct comparisons between observations and explosion model predictions. Such tools have provided useful insights, but the subjective nature with…
The Nature of 500 micron Risers III: a small complete sample
Pérez-Fournon, I.; Clements, D. L.; Riechers, D. +4 more
Herschel surveys have found large numbers of sources with red far-IR colours, and spectral energy distributions (SEDs) rising from 250 to 500 µm: 500 risers. The nature and role of these sources is not fully understood. We here present Submillimeter Array (SMA) interferometric imaging at 200 GHz of a complete sample of five 500 risers with F500 &g…
Exploring the case for hard-X-ray beaming in NGC 6946 X-1
Soria, Roberto; Middleton, Matthew J.; Roberts, Timothy P. +5 more
In order to understand the nature of super-Eddington accretion we must explore both the emission emerging directly from the inflow and its impact on the surroundings. In this paper, we test whether we can use the optical line emission of spatially resolved, ionized nebulae around ultraluminous X-ray sources (ULXs) as a proxy for their X-ray lumino…
The response of the cometary ionosphere to space weather forcing
Timar, Aniko; Nemeth, Zoltan; Burch, James L.
The Rosetta spacecraft observed the temporal evolution of the ion populations within the ionosphere of comet 67P/Churyumov-Gerasimenko. A striking feature of the ion spectrum is represented by the so-called medium-energy ion peaks, which recurrently emerge from the low-energy ion background with their energy levels typically reaching 50 to 1000 eV…
The TRAPUM Small Magellanic Cloud pulsar survey with MeerKAT - II. Nine new radio timing solutions and glitches from young pulsars
Liu, Y.; Haberl, F.; Venter, C. +17 more
We report new radio timing solutions from a 3-yr observing campaign conducted with the MeerKAT and Murriyang telescopes for nine Small Magellanic Cloud pulsars, increasing the number of characterized rotation-powered extragalactic pulsars by 40 per cent. We can infer from our determined parameters that the pulsars are seemingly all isolated, that …
Cometary ion drift energy and temperature at comet 67P/Churyumov-Gerasimeko
Nilsson, Hans; Stenberg Wieser, Gabriella; Moeslinger, Anja +4 more
The Ion Composition Analyzer (ICA) on the Rosetta spacecraft observed both the solar wind and the cometary ionosphere around comet 67P/Churyumov-Gerasimenko for nearly two years. However, observations of low energy cometary ions were affected by a highly negative spacecraft potential, and the ICA ion density estimates were often much lower than pl…
Search for spectroscopic binaries using rotational velocities in five open clusters observed by ESO
Kovalev, Mikhail; Asa'd, Randa; Ahmed, Mariyam
In this paper we detect double-lined spectroscopic binaries (SB2) in five open clusters: NGC 2243, NGC 2420, NGC 3532, NGC 6253, and NGC 6705 (M 11) using a method based on high values of the projected rotational velocity when they are fitted with single star spectral model. Observed spectra were obtained from the European Southern Observatory arc…
Structural properties of subgroups of stars associated with open clusters
Hetem, Annibal; Gregorio-Hetem, Jane
Recent studies have identified star clusters with multiple components based on accurate spatial distributions and/or proper motions from Gaia Data Release 3 (DR3), utilizing diverse diagnostics to gain an understanding of subgroup evolution. These findings motivated us to search for subgroups among the objects examined in our previous work, which …
The variability structure function of the highest luminosity quasars on short time-scales
Tang, Ji-Jia; Wolf, Christian; Tonry, John
The stochastic photometric variability of quasars is known to follow a random-walk phenomenology on emission time-scales of months to years. Some high-cadence rest-frame optical monitoring in the past has hinted at a suppression of variability amplitudes on shorter time-scales of a few days or weeks, opening the question of what drives the suppres…
A novel high-z submm galaxy efficient line survey in ALMA Bands 3 through 8 - an ANGELS pilot
Berta, S.; Andreani, P.; Ivison, R. J. +32 more
We use the Atacama Large sub/Millimetre Array (ALMA) to efficiently observe spectral lines across Bands 3, 4, 5, 6, 7, and 8 at high-resolution (0.5-0.1 arcsec) for 16 bright southern Herschel sources at