Search Publications
Rotational modulation in A and F stars: magnetic stellar spots or convective core rotation?
García, Rafael A.; Antoci, Victoria; Murphy, Simon J. +7 more
The Kepler mission revealed a plethora of stellar variability in the light curves of many stars, some associated with magnetic activity or stellar oscillations. In this work, we analyse the periodic signal in 162 intermediate-mass stars, interpreted as Rossby modes and rotational modulation - the so-called hump and spike feature. We investigate wh…
On the evolution of the size of Lyman alpha haloes across cosmic time: no change in the circumgalactic gas distribution when probed by line emission
Blaizot, Jérémy; Garel, Thibault; Verhamme, Anne +18 more
Lyman α (Lyα) is now routinely used as a tool for studying high-redshift galaxies, and its resonant nature means it can trace neutral hydrogen around star-forming galaxies. Integral field spectrograph measurements of high-redshift Lyα emitters indicate that significant extended Lyα halo emission is ubiquitous around such objects. We present a samp…
The ubiquity of carbon dredge-up in hydrogen-deficient white dwarfs as revealed by GALEX
Blouin, Simon; Kilic, Mukremin; Tremblay, Pier-Emmanuel +1 more
The convective dredge-up of carbon from the interiors of hydrogen-deficient white dwarfs has long been invoked to explain the presence of carbon absorption features in the spectra of cool DQ stars ($T_{\rm eff} \lt 10\,000\,$K). It has been hypothesized that this transport process is not limited to DQ white dwarfs and also operates, albeit less ef…
Intracluster light in the core of z ∼ 2 galaxy proto-clusters
Matharu, J.; Mei, S.; Gonzalez, A. H. +5 more
Intracluster light is thought to originate from stars that were ripped away from their parent galaxies by gravitational tides and galaxy interactions during the build up of the cluster. The stars from such interactions will accumulate over time, so semi-analytic models suggest that the abundance of intracluster stars is negligible in young proto-c…
Photometry and astrometry with JWST - III. A NIRCam-Gaia DR3 analysis of the open cluster NGC 2506
Salaris, M.; Bedin, L. R.; Nardiello, D. +3 more
In the third paper of this series aimed at developing the tools for analysing resolved stellar populations using the cameras on board of the James Webb Space Telescope (JWST), we present a detailed multiband study of the 2 Gyr Galactic open cluster NGC 2506. We employ public calibration data sets collected in multiple filters to: (i) derive improv…
Optical/UV emission in the Tidal Disruption Event ASASSN-14li: implications of disc modelling
Wen, Sixiang; Jonker, Peter G.; Stone, Nicholas C. +2 more
We predict late-time optical/UV emission from tidal disruption events (TDEs) from our slim accretion disc model (Wen et al. 2020) and explore the impact of the black hole mass M•, black hole spin a•, and accretion disc size. We use these synthetic spectra to successfully fit the multiband Swift observations of ASASSN-14li at …
Prospects for future studies using deep imaging: analysis of individual Galactic cirrus filaments
Gontcharov, George A.; Mosenkov, Aleksandr V.; Román, Javier +6 more
The presence of Galactic cirrus is an obstacle for studying both faint objects in our Galaxy and low surface brightness extragalactic structures. With the aim of studying individual cirrus filaments in Sloan Digital Sky Survey (SDSS) Stripe 82 data, we develop techniques based on machine learning and neural networks that allow one to isolate filam…
Probing the variations in the timing of the Sun's polar magnetic field reversals through observations and surface flux transport simulations
Karak, Bidya Binay; Kumar, Pawan; Golubeva, Elena M. +2 more
The polar field reversal is a crucial process in the cyclic evolution of the large-scale magnetic field of the Sun. Various important characteristics of a solar cycle, such as its duration and strength, and also the cycle predictability, are determined by the polar field reversal time. While the regular measurements of solar magnetic field have be…
The large molecular gas fraction of post-starburst galaxies at z > 1
Zanella, A.; Valentino, F.; Magdis, G. +3 more
Post-starburst galaxies are sources that had the last major episode of star formation about 1 Gyr before the epoch of the observations and are on their way to quiescence. It is important to study such galaxies at redshift z > 1, during their main quenching phase, and estimate their molecular gas content to constrain the processes responsible fo…
Discovery and description of two young open clusters in the primordial group of NGC 6871
Casado, Juan; Hendy, Yasser
A primordial group of open clusters containing NGC 6871 is confirmed and described through Gaia DR3 data and the previous literature. It is a star-forming complex containing at least six young open clusters (OCs), including Teutsch 8, FSR 198, and Biurakan 2. Two nearby OCs (Casado 82 and Casado-Hendy 1) are newly identified and studied in detail …