Search Publications
SORA: Stellar occultation reduction and analysis
Sicardy, B.; Gomes-Júnior, A. R.; Braga-Ribas, F. +6 more
The stellar occultation technique provides competitive accuracy in determining the sizes, shapes, astrometry, etc., of the occulting body, comparable to in-situ observations by spacecraft. With the increase in the number of known Solar system objects expected from the LSST, the highly precise astrometric catalogs, such as Gaia, and the improvement…
Nothing to see here: failed supernovae are faint or rare
Fraser, M.; Byrne, R. A.
The absence of Type IIP core-collapse supernovae arising from progenitors above 17 solar masses suggests the existence of another evolutionary path by which massive stars end their lives. The direct collapse of a stellar core to a black hole without the production of a bright, explosive transient is expected to produce a long-lived, dim, red trans…
Gaia DR3 in 6D: the search for fast hypervelocity stars and constraints on the galactic centre environment
Marchetti, Tommaso; Evans, Fraser A.; Rossi, Elena Maria
The third data release (DR3) of the European Space Agency satellite Gaia provides coordinates, parallaxes, proper motions, and radial velocities for a sample of ~34 million stars. We use the combined 6D phase space information to search for hypervelocity stars (HVSs), unbound stars accelerated by dynamical processes happening in the Galactic Centr…
Angular clustering properties of the DESI QSO target selection using DR9 Legacy Imaging Surveys
Myers, Adam D.; Palanque-Delabrouille, Nathalie; Yèche, Christophe +12 more
The quasar target selection for the upcoming survey of the Dark Energy Spectroscopic Instrument (DESI) will be fixed for the next 5 yr. The aim of this work is to validate the quasar selection by studying the impact of imaging systematics as well as stellar and galactic contaminants, and to develop a procedure to mitigate them. Density fluctuation…
Can tides explain the low dark matter density in Fornax?
Fattahi, Azadeh; Read, Justin I.; Frenk, Carlos S. +1 more
The low dark matter density in the Fornax dwarf galaxy is often interpreted as being due to the presence of a constant density 'core', but it could also be explained by the effects of Galactic tides. The latter interpretation has been disfavoured because it is apparently inconsistent with the orbital parameters and star formation history of Fornax…
Evolution of the Sun's activity and the poleward transport of remnant magnetic flux in Cycles 21-24
Banerjee, Dipankar; Karak, Bidya Binay; Kumar, Pawan +4 more
Detailed study of the solar magnetic field is crucial to understand its generation, transport, and reversals. The timing of the reversals may have implications on space weather and thus identification of the temporal behaviour of the critical surges that lead to the polar field reversals is important. We analyse the evolution of solar activity and…
The COMBS Survey - III. The chemodynamical origins of metal-poor bulge stars
Kobayashi, Chiaki; Hawkins, Keith; Lucey, Madeline +6 more
The characteristics of the stellar populations in the Galactic bulge inform and constrain the Milky Way's formation and evolution. The metal-poor population is particularly important in light of cosmological simulations, which predict that some of the oldest stars in the Galaxy now reside in its centre. The metal-poor bulge appears to consist of m…
A census of X-ray millisecond pulsars in globular clusters
Zhao, Jiaqi; Heinke, Craig O.
We present a comprehensive census of X-ray millisecond pulsars (MSPs) in 29 Galactic globular clusters (GCs), including 68 MSPs with confirmed X-ray luminosities and 107 MSPs with X-ray upper limits. We compile previous X-ray studies of GC MSPs, and add new analyses of six MSPs (PSRs J1326-4728A, J1326-4728B, J1518+0204C, J1717+4308A, J1737-0314A,…
The complex stellar system M 22: confirming abundance variations with high precision differential measurements
Milone, A. P.; Marino, A. F.; Legnardi, M. V. +8 more
M 22 (NGC 6656) is a chemically complex globular cluster-like system reported to harbour heavy element abundance variations. However, the extent of these variations and the origin of this cluster is still debated. In this work, we investigate the chemical in-homogeneity of M 22 using differential line-by-line analysis of high-quality (R = 110 000,…
A Gaia EDR3 search for tidal tails in disintegrating open clusters
Vaidya, Kaushar; Rao, Khushboo K.; Agarwal, Manan +2 more
We carry out a search for tidal tails in a sample of open clusters with known relatively elongated morphology. We identify the member stars of these clusters from the precise astrometric and deep photometric data from Gaia Early Data Release 3 using the robust membership determination algorithm, ML-MOC. We identify 46 open clusters having a stella…