Search Publications
X-ray time lags in AGN: inverse-Compton scattering and spherical corona model
Chainakun, P.; Young, A. J.; Hancock, S. +1 more
We develop a physically motivated, spherical corona model to investigate the frequency-dependent time lags in active galactic nucleus (AGN). The model includes the effects of Compton up-scattering between the disc ultraviolet (UV) photons and coronal electrons, and the subsequent X-ray reverberation from the disc. The time lags are associated with…
Quasar lenses in the south: searches over the DES public footprint
Agnello, Adriano; Spiniello, Chiara
We have scanned 5000 deg2 of Southern Sky to search for strongly lensed quasars with five methods, all source oriented, but based on different assumptions and selection criteria. We present a list of high-grade candidates from each method (totalling 98 unique, new candidates), to facilitate follow-up spectroscopic campaigns, including t…
The PAU survey: star-galaxy classification with multi narrow-band data
Carretero, J.; Castander, F. J.; García-Bellido, J. +18 more
Classification of stars and galaxies is a well-known astronomical problem that has been treated using different approaches, most of them relying on morphological information. In this paper, we tackle this issue using the low-resolution spectra from narrow-band photometry, provided by the Physics of the Accelerating Universe survey. We find that, w…
Is helium the key parameter in the extended colour spread of the first generation stars in M3?
Milone, A. P.; Cordoni, G.; Marino, A. F. +4 more
The study of the `chromosome maps' of Galactic globular clusters has shown that the stars identified as `first generation' often define an extended sequence in the mF275W - mF814W colour, whose straightforward interpretation, by comparison with synthetic spectra, is that they are inhomogeneous in helium content. The cluster M…
The time delay between star formation quenching and morphological transformation of galaxies in clusters: a phase-space view of EDisCS
Moustakas, John; Aragón-Salamanca, Alfonso; Milvang-Jensen, Bo +5 more
We explore the possible effect of cluster environments on the structure and star formation histories of galaxies by analysing the projected phase-space (PPS) of intermediate-redshift clusters (0.4 ≤ z ≤ 0.8). HST I-band imaging data from the ESO Distant Cluster Survey (EDisCS) allow us to measure deviations of the galaxies' light distributions fro…
A multiwavelength analysis of a collection of short-duration GRBs observed between 2012 and 2015
Cepa, J.; Troja, E.; Lee, W. H. +71 more
We investigate the prompt emission and the afterglow properties of short-duration gamma-ray burst (sGRB) 130603B and another eight sGRB events during 2012-2015, observed by several multiwavelength facilities including the Gran Canarias Telescope 10.4 m telescope. Prompt emission high energy data of the events were obtained by INTEGRAL-SPI-ACS, Swi…
The role of multiple images and model priors in measuring H0 from supernova Refsdal in galaxy cluster MACS J1149.5+2223
Liesenborgs, Jori; Williams, Liliya L. R.
Multiple image gravitational lensing systems with measured time delays provide a promising one-step method for determining H0. MACS J1149, which lenses SN Refsdal into a quad S1-S4, and two other widely separated images, SX and SY, is a perfect candidate. If time delays are pinned down, the remaining uncertainty arises from the mass dis…
The structural properties of classical bulges and discs from z ∼ 2
Barro, Guillermo; Pérez-González, Pablo G.; Kocevski, Dale D. +19 more
We study the rest-frame optical mass-size relation of bulges and discs from z ∼ 2 to z ∼ 0 for a complete sample of massive galaxies in the CANDELS fields using two-component Sérsic models. Discs and star-forming galaxies follow similar mass-size relations. The mass-size relation of bulges is less steep than the one of quiescent galaxies (best-fit…
NOEMA maps the CO J = 2 - 1 environment of the red supergiant µ Cep
Decin, L.; Richards, A. M. S.; Royer, P. +8 more
Red supergiant stars are surrounded by a gaseous and dusty circumstellar environment created by their mass loss, which spreads heavy elements into the interstellar medium. The structure and dynamics of this envelope are crucial to understand the processes driving the red supergiant mass loss and the shaping of the pre-supernova ejecta. We have obs…
Characterizing circumgalactic gas around massive ellipticals at z ≈ 0.4 - III. The galactic environment of a chemically pristine Lyman limit absorber
Bouché, Nicolas; Johnson, Sean D.; Marino, Raffaella Anna +7 more
This paper presents a study of the galactic environment of a chemically pristine (<0.6 per cent solar metallicity) Lyman Limit system (LLS) discovered along the sightline towards QSO SDSSJ 135726.27+043541.4 (zQSO = 1.233) at projected distance d = 126 physical kpc (pkpc) from a luminous red galaxy (LRG) at z = 0.33. Combining deep H…