Search Publications
Flashlights: an off-caustic lensed star at redshift z = 1.26 in Abell 370
Broadhurst, Tom; Filippenko, Alexei V.; Kelly, Patrick L. +11 more
We report the discovery of a transient seen in a strongly lensed arc at redshift zs = 1.2567 in Hubble Space Telescope imaging of the Abell 370 galaxy cluster. The transient is detected at 29.51 ± 0.14 AB mag in a WFC3/UVIS F200LP difference image made using observations from two different epochs, obtained in the framework of the Flashl…
TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf
Barclay, Thomas; Hellier, Coel; Triaud, Amaury H. M. J. +137 more
We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (~200 mas yr-1), low metallicity ([Fe/H]≈-0.28) K-dwarf with a mass of 0.68 ± 0.05 M⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometri…
RASS-MCMF: a full-sky X-ray selected galaxy cluster catalogue
Klein, Matthias; Hernández-Lang, Daniel; Mohr, Joseph J. +2 more
We present the RASS-MCMF catalogue of 8449 X-ray selected galaxy clusters over 25 000 deg2 of extragalactic sky. The accumulation of deep multiband optical imaging data, the development of the Multi-Component Matched Filter (MCMF) cluster confirmation algorithm, and the release of the DESI Legacy Survey DR10 catalogue makes it possible …
The disappearances of six supernova progenitors
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Kelly, Patrick L. +8 more
As part of a larger completed Hubble Space Telescope (HST) Snapshot program, we observed the sites of six nearby core-collapse supernovae (SNe) at high spatial resolution: SN 2012A, SN 2013ej, SN 2016gkg, SN 2017eaw, SN 2018zd, and SN 2018aoq. These observations were all conducted at sufficiently late times in each SN's evolution to demonstrate th…
GRB 160410A: The first chemical study of the interstellar medium of a short GRB
D'Avanzo, P.; Campana, S.; Melandri, A. +27 more
Short gamma-ray bursts (SGRBs) are produced by the coalescence of compact binary systems which are remnants of massive stars. GRB 160410A is classified as a short-duration GRB with extended emission and is currently the farthest SGRB with a redshift determined from an afterglow spectrum and also one of the brightest SGRBs to date. The fast reactio…
A twisted and precessing Cepheid warp in the outer Milky Way disc
Schönrich, Ralph; Dehnen, Walter; Semczuk, Marcin
We examine the Galactic warp in a sample of all classical Cepheids with Gaia Data Release 3 radial velocity. In each radial bin, we determine (1) the inclined plane normal to the mean orbital angular momentum of the stars and (2) that best fitting their positions. We find no warping inside $R\approx 11\,$kpc; for larger R, the disc is increasingly…
Modelling of the post-asymptotic giant branch phase as a tool to understand asymptotic giant branch evolution and nucleosynthesis
Dell'Agli, F.; Ventura, P.; Van Winckel, H. +3 more
We study a sample of single Galactic post-asymptotic giant branch (post-AGB) stars with known surface chemical composition. Gaia EDR3 and Gaia DR3 parallaxes have enabled accurate determinations of the luminosities of these objects, thus making it possible to characterize them in terms of their initial masses, chemical compositions, and progenitor…
A sample of fast radio bursts discovered and localized with MeerTRAP at the MeerKAT telescope
Prochaska, J. Xavier; Kramer, M.; Wu, J. +14 more
We present a sample of well-localized fast radio bursts (FRBs) discovered by the MeerTRAP project at the MeerKAT telescope in South Africa. We discovered the three FRBs in single coherent tied-array beams and localized them to an area of ~1 arcmin2. We investigate their burst properties, scattering, repetition rates, and localizations i…
Improving Star Cluster Age Estimates in PHANGS-HST Galaxies and the Impact on Cluster Demographics in NGC 628
Kruijssen, J. M. Diederik; Klessen, Ralf S.; Schinnerer, Eva +29 more
A long-standing problem when deriving the physical properties of stellar populations is the degeneracy between age, reddening, and metallicity. When a single metallicity is used for all the star clusters in a galaxy, this degeneracy can result in 'catastrophic' errors for old globular clusters. Typically, approximately 10-20 per cent of all cluste…
Empirical constraints on the turbulence in QSO host nebulae from velocity structure function measurements
Johnson, Sean D.; Zahedy, Fakhri S.; Chen, Hsiao-Wen +9 more
We present the first empirical constraints on the turbulent velocity field of the diffuse circumgalactic medium around four luminous quasi-stellar objects (QSOs) at z ≈ 0.5-1.1. Spatially extended nebulae of ≈50-100 physical kpc in diameter centred on the QSOs are revealed in [O II] $\lambda \lambda \, 3727,3729$ and/or [O III] $\lambda \, 5008$ e…