Search Publications
Spatial variations in the Milky Way disc metallicity-age relation
Feuillet, Diane K.; Lind, Karin; García-Hernández, D. A. +5 more
Stellar ages are a crucial component to studying the evolution of the Milky Way. Using Gaia DR2 distance estimates, it is now possible to estimate stellar ages for a larger volume of evolved stars through isochrone matching. This work presents [M/H]-age and [α/M]-age relations derived for different spatial locations in the Milky Way disc. These re…
Feedback from massive stars at low metallicities: MUSE observations of N44 and N180 in the Large Magellanic Cloud
Testi, L.; Evans, C. J.; Kruijssen, J. M. D. +5 more
We present MUSE integral field data of two H II region complexes in the Large Magellanic Cloud: N44 and N180. Both regions consist of a main superbubble and a number of smaller, more compact H II regions that formed on the edge of the superbubble. For a total of 11 H II regions, we systematically analyse the radiative and mechanical feedback from …
A new RASS galaxy cluster catalogue with low contamination extending to z ∼ 1 in the DES overlap region
Smith, M.; D'Andrea, C. B.; Abbott, T. M. C. +63 more
We present the MARD-Y3 catalogue of between 1086 and 2171 galaxy clusters (52 per cent and 65 per cent new) produced using multicomponent matched filter (MCMF) follow-up in 5000 deg2 of DES-Y3 optical data of the ∼20 000 overlapping ROSAT All-Sky Survey source catalogue (2RXS) X-ray sources. Optical counterparts are identified as peaks …
The lowest detected stellar Fe abundance: the halo star SMSS J160540.18-144323.1
Schmidt, B. P.; Da Costa, G. S.; Marino, A. F. +12 more
We report the discovery of SMSS J160540.18-144323.1, a new ultra metal-poor halo star discovered with the SkyMapper telescope. We measure [{Fe}/{H}]= -6.2 ± 0.2 (1D LTE), the lowest ever detected abundance of iron in a star. The star is strongly carbon-enhanced, [{C}/{Fe}] = 3.9 ± 0.2, while other abundances are compatible with an α-enhanced solar…
Multiphase circumgalactic medium probed with MUSE and ALMA
Pettini, Max; York, Donald G.; Hamanowicz, Aleksandra +9 more
Galaxy haloes appear to be missing a large fraction of their baryons, most probably hiding in the circumgalactic medium (CGM), a diffuse component within the dark matter halo that extends far from the inner regions of the galaxies. A powerful tool to study the CGM gas is offered by absorption lines in the spectra of background quasars. Here, we pr…
Common origin for Hercules-Aquila and Virgo Clouds in Gaia DR2
Belokurov, Vasily; Koposov, Sergey E.; Simion, Iulia T.
We use a sample of ∼350 RR Lyrae stars with radial velocities and Gaia Data Release 2 proper motions to study orbital properties of the Hercules-Aquila Cloud (HAC) and Virgo Over-density (VOD). We demonstrate that both structures are dominated by stars on highly eccentric orbits, with pericentres around ∼1 kpc and apocentres at 15-25 kpc from the …
The period-luminosity relation for δ Scuti stars using Gaia DR2 parallaxes
Bedding, Timothy R.; Murphy, Simon J.; Hey, Daniel R. +2 more
We have examined the period-luminosity (P-L) relation for δ Scuti stars using Gaia DR2 parallaxes. We included 228 stars from the catalogue of Rodríguez et al., as well as 1124 stars observed in the 4-yr Kepler mission. For each star, we considered the dominant pulsation period, and used DR2 parallaxes and extinction corrections to determine absol…
NGTS-4b: A sub-Neptune transiting in the desert
Jackman, James A. G.; Wheatley, Peter J.; Bayliss, Daniel +48 more
We report the discovery of NGTS-4b, a sub-Neptune-sized planet transiting a 13th magnitude K-dwarf in a 1.34 d orbit. NGTS-4b has a mass M = 20.6 ± 3.0 M⊕ and radius R = 3.18 ± 0.26 R⊕, which places it well within the so-called `Neptunian Desert'. The mean density of the planet (3.45 ± 0.95 g cm-3) is consistent wi…
Cosmological constraints on an exponential interaction in the dark sector
Yang, Weiqiang; Pan, Supriya; Paliathanasis, Andronikos
Cosmological models where dark matter (DM) and dark energy (DE) interact with each other are the general scenarios in compared to the non-interacting models. The interaction is usually motivated from the phenomenological ground and thus there is no such rule to prefer a particular interaction between DM and DE. Being motivated, in this work, allow…
A contribution of star-forming clumps and accreting satellites to the mass assembly of z ∼ 2 galaxies
Daddi, E.; Le Floc'h, E.; Bournaud, F. +14 more
We investigate the contribution of clumps and satellites to the galaxy mass assembly. We analysed spatially resolved HubbleSpace Telescope observations (imaging and slitless spectroscopy) of 53 star-forming galaxies at z ∼ 1-3. We created continuum and emission line maps and pinpointed residual `blobs' detected after subtracting the galaxy disc. T…