Search Publications
Constraints on warm dark matter from UV luminosity functions of high-z galaxies with Bayesian model comparison
Rudakovskyi, Anton; Mesinger, Andrei; Savchenko, Denys +1 more
The number density of small dark matter (DM) haloes hosting faint high-redshift galaxies is sensitive to the DM free-streaming properties. However, constraining these DM properties is complicated by degeneracies with the uncertain baryonic physics governing star formation. In this work, we use a flexible astrophysical model and a Bayesian inferenc…
A new lepto-hadronic model applied to the first simultaneous multiwavelength data set for Cygnus X-1
Bremer, M.; Wilms, J.; Uttley, P. +10 more
Cygnus X-1 is the first Galactic source confirmed to host an accreting black hole. It has been detected across the entire electromagnetic spectrum from radio to GeV gamma-rays. The source's radio through mid-infrared radiation is thought to originate from the relativistic jets. The observed high degree of linear polarization in the MeV X-rays sugg…
A high-contrast search for variability in HR 8799bc with VLT-SPHERE
Wagner, Kevin; Apai, Dániel; Zurlo, Alice +11 more
The planets HR8799bc display nearly identical colours and spectra as variable young exoplanet analogs such as VHS 1256-1257ABb and PSO J318.5-22, and are likely to be similarly variable. Here we present results from a 5-epoch SPHERE IRDIS broadband-H search for variability in these two planets. HR 8799b aperture photometry and HR 8799bc negative s…
The effects of rotation on the lithium depletion of G- and K-dwarfs in Messier 35
Jeffries, R. D.; Deliyannis, Constantine P.; Sun, Qinghui +1 more
New fibre spectroscopy and radial velocities from the WIYN telescope are used to measure photospheric lithium in 242 high-probability, zero-age main-sequence F- to K-type members of the rich cluster M35. Combining these with published rotation periods, the connection between lithium depletion and rotation is studied in unprecedented detail. At T
Stars and gas in the most metal-poor galaxies - I. COS and MUSE observations of SBS 0335-052E
Feltre, Anna; Charlot, Stéphane; Chevallard, Jacopo +5 more
Among the nearest most metal-poor starburst-dwarf galaxies known, SBS 0335-052E is the most luminous in integrated nebular He II λ4686 emission. This makes it a unique target to test spectral synthesis models and spectral interpretation tools of the kind that will be used to interpret future rest-frame UV observations of primeval galaxies. Previou…
3D MHD astrospheres: applications to IRC-10414 and Betelgeuse
Meyer, D. M. -A.; Mignone, A.; Petrov, M. +3 more
A significative fraction of all massive stars in the Milky Way move supersonically through their local interstellar medium (ISM), producing bow shock nebulae by wind-ISM interaction. The stability of these observed astrospheres around cool massive stars challenges precedent 2D (magneto-)hydrodynamical (MHD) simulations of their surroundings. We pr…
The White Dwarf Binary Pathways Survey - IV. Three close white dwarf binaries with G-type secondary stars
Gänsicke, B. T.; Rebassa-Mansergas, A.; Raddi, R. +12 more
Constraints from surveys of post-common envelope binaries (PCEBs) consisting of a white dwarf plus an M-dwarf companion have led to significant progress in our understanding of the formation of close white dwarf binary stars with low-mass companions. The white dwarf binary pathways project aims at extending these previous surveys to larger seconda…
Stellar substructures in the periphery of the Magellanic Clouds with the VISTA hemisphere survey from the red clump and other tracers
Sun, Ning-Chen; de Grijs, Richard; Ripepi, Vincenzo +11 more
We study the morphology of the stellar periphery of the Magellanic Clouds in search of substructure using near-infrared imaging data from the Visible and Infrared Survey Telescope for Astronomy Hemisphere Survey. Based on the selection of different stellar populations using the (J - Ks, Ks) colour-magnitude diagram, we confir…
The impact of mixing treatments on cloud modelling in 3D simulations of hot Jupiters
Sing, D. K.; Parmentier, V.; Mikal-Evans, T. +7 more
We present results of 3D hydrodynamical simulations of HD209458b including a coupled, radiatively active cloud model (EDDYSED). We investigate the role of the mixing by replacing the default convective treatment used in previous works with a more physically relevant mixing treatment (Kzz) based on global circulation. We find that uncert…
TESS cycle 1 observations of roAp stars with 2-min cadence data
Derekas, A.; Niemczura, E.; Handberg, R. +41 more
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp stars. Amongst these stars we discover the roAp star with the longest pulsation period, another with the shorte…