Search Publications
Catalogues of active galactic nuclei from Gaia and unWISE data
McMahon, Richard G.; Belokurov, Vasily; Auger, Matthew W. +4 more
We present two catalogues of active galactic nucleus (AGN) candidates selected from the latest data of two all-sky surveys - Data Release 2 of the Gaia mission and the unWISE catalogue of the Wide-field Infrared Survey Explorer (WISE). We train a random forest classifier to predict the probability of each source in the Gaia-unWISE joint sample bei…
Automated distant galaxy merger classifications from Space Telescope images using the Illustris simulation
Torrey, Paul; Rodriguez-Gomez, Vicente; Vogelsberger, Mark +5 more
We present image-based evolution of galaxy mergers from the Illustris cosmological simulation at 12 time-steps over 0.5 < z < 5. To do so, we created approximately one million synthetic deep Hubble Space Telescope and James Webb Space Telescope images and measured common morphological indicators. Using the merger tree, we assess methods to o…
Gaia Data Release 2 catalogue of extremely low-mass white dwarf candidates
Pelisoli, Ingrid; Vos, Joris
Extremely low-mass white dwarf stars (ELMs) are M < 0.3 M⊙ helium-core white dwarfs born either as a result of a common-envelope phase or after a stable Roche lobe overflow episode in a multiple system. The Universe is not old enough for ELMs to have formed through single-star evolution channels. As remnants of binary evolution, ELMs…
The MUSE Ultra Deep Field (MUDF). II. Survey design and the gaseous properties of galaxy groups at 0.5 < z < 1.5
Smail, I.; Cristiani, S.; D'Odorico, V. +12 more
We present the goals, design, and first results of the MUSE Ultra Deep Field (MUDF) survey, a large programme using the Multi Unit Spectroscopic Explorer (MUSE) instrument at the ESO Very Large Telescope. The MUDF survey is collecting ≈150 h on-source of integral field optical spectroscopy in a 1.5 × 1.2 arcmin2 region which hosts sever…
The AGN fuelling/feedback cycle in nearby radio galaxies I. ALMA observations and early results
Davis, Timothy A.; Bureau, Martin; Mignano, Arturo +7 more
This is the first paper of a series exploring the multifrequency properties of a sample of 11 nearby low-excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars, warm and cold gas, radio jets) with the aim of improving our understanding of the active galactic nucleus (AGN) f…
Standard Galactic field RR Lyrae II: a Gaia DR2 calibration of the period-Wesenheit-metallicity relation
Madore, Barry F.; Freedman, Wendy L.; Sarajedini, Ata +9 more
RR Lyrae stars have long been popular standard candles, but significant advances in methodology and technology have been made in recent years to increase their precision as distance indicators. We present multiwavelength (optical UBVRcIc and Gaia G, BP, RP; near-infrared JHKs; mid-infrared [3.6], [4.5]) period-lumi…
Evident black hole-bulge coevolution in the distant universe
Alexander, D. M.; Brandt, W. N.; Yang, G. +4 more
Observations in the local universe show a tight correlation between the masses of supermassive black holes (SMBHs; MBH) and host-galaxy bulges (Mbulge), suggesting a strong connection between SMBH and bulge growth. However, direct evidence for such a connection in the distant universe remains elusive. We have studied sample-a…
Binary asteroseismic modelling: isochrone-cloud methodology and application to Kepler gravity mode pulsators
Aerts, C.; Pápics, P. I.; Bowman, D. M. +5 more
The simultaneous presence of variability due to both pulsations and binarity is no rare phenomenon. Unfortunately, the complexities of dealing with even one of these sources of variability individually means that the other signal is often treated as a nuisance and discarded. However, both types of variability offer means to probe fundamental stell…
H α morphologies of star clusters: a LEGUS study of H II region evolution time-scales and stochasticity in low-mass clusters
Herrero, A.; Cignoni, M.; Calzetti, D. +25 more
The morphology of H II regions around young star clusters provides insight into the time-scales and physical processes that clear a cluster's natal gas. We study ∼700 young clusters (≤10 Myr) in three nearby spiral galaxies (NGC 7793, NGC 4395, and NGC 1313) using Hubble Space Telescope (HST) imaging from LEGUS (Legacy ExtraGalactic Ultraviolet Su…
Quasar and galaxy classification in Gaia Data Release 2
Fouesneau, Morgan; Bailer-Jones, Coryn A. L.; Andrae, Rene
We construct a supervised classifier based on Gaussian Mixture Models to probabilistically classify objects in Gaia data release 2 (GDR2) using only photometric and astrometric data in that release. The model is trained empirically to classify objects into three classes - star, quasar, galaxy - for G ≥ 14.5 mag down to the Gaia magnitude limit of …