Search Publications
The detection of radio emission from known X-ray flaring star EXO 040830-7134.7
Woudt, P. A.; Williams, D. R. A.; Fender, R. P. +4 more
We report the detection of radio emission from the known X-ray flaring star EXO 040830-7134.7 during Karoo Array Telescope (MeerKAT) observations of the nearby cataclysmic variable VW Hydri. We have three epochs of MeerKAT observations, where the star is not detected in the first epoch, is detected in the second epoch, and is marginally detected i…
Relic jet activity in 'Hanny's Voorwerp' revealed by the LOFAR two metre sky survey
Hardcastle, M. J.; Smith, D. J. B.; Drake, A. B. +1 more
We report new observations of 'Hanny's Voorwerp' (hereafter HV) taken from the second data release of the LOFAR Two-metre Sky Survey (LoTSS). HV is a highly-ionized region in the environs of the galaxy IC2497, first discovered by the Galaxy Zoo project. The new 150 MHz observations are considered in the context of existing multi frequency radio da…
SoUthern Cluster sCale Extended Source Survey (SUCCESS): a GMRT and Meerkat study of nine massive galaxy clusters
Kale, R.; Venturi, T.; Joshi, D. C. +7 more
We aim to carry out a radio study of the SoUthern Cluster sCale Extended Source Survey (SUCCESS) sample consisting of 20 massive (M500 > 5 × 1014 M⊙), nearby (redshift <0.3) and southern (-50° < δ < -30°) galaxy clusters detected by the Planck satellite and the South Pole Telescope. Here, we report targ…
A new method to detect globular clusters with the S-PLUS survey
Cortesi, Arianna; Chies-Santos, Ana L.; Forbes, Duncan A. +17 more
In this paper, we describe a new method to select globular cluster (GC) candidates, including galaxy subtraction with unsharp masking, template fitting techniques, and the inclusion of Gaia's proper motions. We report the use of the 12-band photometric system used by S-PLUS to determine radial velocities and stellar populations of GCs around nearb…
On the use of field RR Lyrae as galactic probes - VI. Mixed mode RR Lyrae variables in Fornax and in nearby dwarf galaxies
Di Criscienzo, M.; Marinoni, S.; Marrese, P. M. +11 more
We investigate the properties of the mixed-mode (RRd) RR Lyrae (RRL) variables in the Fornax dwarf spheroidal (dSph) galaxy by using B- and V-band time series collected over 24 yr. We compare the properties of the RRds in Fornax with those in the Magellanic Clouds and in nearby dSphs, with special focus on Sculptor. We found that the ratio of RRds…
Spectral-timing of AGN ionized outflows with Athena
Costantini, E.; Uttley, P.; Juráňová, A.
Spectral-timing techniques have proven valuable in studying the interplay between the X-ray corona and the accretion disc in variable active galactic nuclei (AGNs). Under certain conditions, photoionized outflows emerging from central AGN regions also play a role in the observable spectral-timing properties of the nuclear components. The variable …
Helium line emissivities for nebular astrophysics
Del Zanna, G.; Storey, P. J.
We present the results of several collisional-radiative models describing optically thin emissivities of the main lines in neutral helium formed by recombination, for a grid of electron temperatures and densities, typical of H II regions and planetary nebulae. Accurate emissivities are required for example to measure the helium abundance in nebula…
Transit timings variations in the three-planet system: TOI-270
Gorjian, Varoujan; Mikal-Evans, Thomas; Triaud, Amaury H. M. J. +69 more
We present ground- and space-based photometric observations of TOI-270 (L231-32), a system of three transiting planets consisting of one super-Earth and two sub-Neptunes discovered by TESS around a bright (K-mag = 8.25) M3V dwarf. The planets orbit near low-order mean-motion resonances (5:3 and 2:1) and are thus expected to exhibit large transit t…
Period-change rates in Large Magellanic Cloud Cepheids revisited
Catelan, M.; Orquera-Rojas, C.; Torres, P. +10 more
The period-change rate (PCR) of pulsating variable stars is a useful probe of changes in their interior structure, and thus of their evolutionary stages. So far, the PCRs of classical Cepheids in the Large Magellanic Cloud (LMC) have been explored in a limited sample of the total population of these variables. Here, we use a template-based method …
The VMC survey - XLVII. Turbulence-controlled hierarchical star formation in the Large Magellanic Cloud
Sun, Ning-Chen; de Grijs, Richard; Marconi, Marcella +9 more
We perform a statistical clustering analysis of upper main-sequence stars in the Large Magellanic Cloud (LMC) using data from the Visible and Infrared Survey Telescope for Astronomy survey of the Magellanic Clouds. We map over 2500 young stellar structures at 15 significance levels across ~120 square degrees centred on the LMC. The structures have…