Search Publications
The white dwarf binary pathways survey - VI. Two close post-common envelope binaries with TESS light curves
Gänsicke, B. T.; Rebassa-Mansergas, A.; Raddi, R. +9 more
Establishing a large sample of post-common-envelope binaries (PCEBs) that consist of a white dwarf plus an intermediate mass companion star of spectral type AFGK, offers the potential to provide new constraints on theoretical models of white dwarf binary formation and evolution. Here, we present a detailed analysis of two new systems, TYC 110-755-…
Asteroseismology of RR Lyrae stars with non-radial modes
Smolec, Radosław; Netzel, Henryka
The additional signals observed in the frequency spectra of the first-overtone RR Lyrae stars, which form a period ratio around 0.61 with the period of the first overtone, are a common phenomenon for RRc and RRd stars, as well as for first-overtone classical Cepheids. The recently proposed model explains these signals as harmonics of non-radial mo…
The Mantis Network II: examining the 3D high-resolution observable properties of the UHJs WASP-121b and WASP-189b through GCM modelling
Lee, Elspeth K. H.; Heng, Kevin; Tsai, Shang-Min +4 more
The atmospheres of ultra hot Jupiters (UHJs) are prime targets for the detection of molecules and atoms at both low and high spectral resolution. We study the atmospheres of the UHJs WASP-121b and WASP-189b by performing 3D general circulation models (GCMs) of these planets using high temperature correlated-k opacity schemes with ultra-violet (UV)…
A new method for finding nearby white dwarfs exoplanets and detecting biosignatures
Vanderburg, Andrew; Lustig-Yaeger, Jacob; Stevenson, Kevin B. +5 more
We demonstrate that the James Webb Space Telescope (JWST) can detect infrared (IR) excess from the blended light spectral energy distribution of spatially unresolved terrestrial exoplanets orbiting nearby white dwarfs. We find that JWST is capable of detecting warm (habitable-zone; Teq = 287 K) Earths or super-Earths and hot (400-1000 K…
The impact of a massive Sagittarius dSph on GD-1-like streams
Price-Whelan, Adrian M.; Belokurov, Vasily; Evans, N. Wyn +1 more
We investigate the effects of a massive ($\gtrsim 4\times 10^{10}\, \mathrm{M}_\odot$) Sagittarius dwarf spheroidal galaxy (Sgr) on stellar streams using test particle simulations in a realistic Milky Way potential. We find that Sgr can easily disrupt streams formed more than ~3 Gyr ago, while stars stripped more recently are generally unaffected.…
The RapidXMM upper limit server: X-ray aperture photometry of the XMM-Newton archival observations
Georgakakis, A.; Georgantopoulos, I.; Kretschmar, P. +4 more
This paper presents the construction of the RapidXMM database that is available through the XMM-Newton Science Archive and offers access to upper limits and aperture photometry across the field of view of the XMM-Newton Pointed and Slew Survey observations. The feature of RapidXMM is speed. It enables the fast retrieval of X-ray upper limits and p…
21 new long-term variables in the GX 339-4 field: two years of MeerKAT monitoring
Heywood, I.; Wijers, R. A. M. J.; Woudt, P. A. +14 more
We present 21 new long-term variable radio sources found commensally in 2 yr of weekly MeerKAT monitoring of the low-mass X-ray binary GX 339-4. The new sources are vary on time-scales of weeks to months and have a variety of light-curve shapes and spectral index properties. Three of the new variable sources are coincident with multiwavelength cou…
Stellar mass segregation as separating classifier between globular clusters and ultrafaint dwarf galaxies
Hilker, M.; Baumgardt, H.; Faller, J. +2 more
We have determined the amount of stellar mass segregation in over 50 globular clusters and ultrafaint dwarf galaxy candidates based on deep HST- and ground-based photometry. We find that the amount of mass segregation in globular clusters is strongly correlated with their relaxation time and that all clusters with relaxation times of the order of …
Identifying blue large amplitude pulsators from Gaia DR2 and ZTF DR3
Lam, Marco C.; McWhirter, Paul Ross
Blue large amplitude pulsators (BLAPs) are hot, subluminous stars undergoing rapid variability with periods of under 60 min. They have been linked with the early stages of pre-white dwarfs and hot subdwarfs. They are a rare class of variable star due to their evolutionary history within interacting binary systems and the short time-scales relative…
Blanco DECam Bulge Survey (BDBS) IV: Metallicity distributions and bulge structure from 2.6 million red clump stars
Clarkson, William I.; Rich, R. Michael; Kunder, Andrea +12 more
We present photometric metallicity measurements for a sample of 2.6 million bulge red clump stars extracted from the Blanco DECam Bulge Survey (BDBS). Similar to previous studies, we find that the bulge exhibits a strong vertical metallicity gradient, and that at least two peaks in the metallicity distribution functions appear at b < -5°. We ca…