Search Publications
Cosmological parameters, shear maps and power spectra from CFHTLenS using Bayesian hierarchical inference
Jaffe, Andrew H.; Heavens, Alan; Alsing, Justin
We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the Canada-France-Hawaii Telescope (CFHTLenS) weak lensing survey - the first application of this method to data. In the first approach, we sample the joint posterior distribution of the shear maps and power spectra by Gib…
H0LiCOW - II. Spectroscopic survey and galaxy-group identification of the strong gravitational lens system HE 0435-1223
Treu, T.; Auger, M. W.; Koopmans, L. V. E. +15 more
Galaxies located in the environment or along the line of sight towards gravitational lenses can significantly affect lensing observables, and can lead to systematic errors on the measurement of H0 from the time-delay technique. We present the results of a systematic spectroscopic identification of the galaxies in the field of view of th…
Probing the intra-group medium of a z = 0.28 galaxy group
Tejos, N.; Morris, S. L.; Cantalupo, S. +4 more
We present new MUSE observations of a galaxy group probed by a background quasar. The quasar sightline passes between multiple z = 0.28 galaxies, whilst showing at the same redshift low-ionized metal line species, including Ca II, Mg I, Mg II and Fe II. Based on the galaxy redshifts measured from the MUSE data, we estimate the galaxies to be part …
Major mergers are not significant drivers of star formation or morphological transformation around the epoch of peak cosmic star formation
Conselice, C. J.; Hartley, W.; Mortlock, A. +2 more
We investigate the contribution of major mergers (mass ratios >1: 5) to stellar mass growth and morphological transformations around the epoch of peak cosmic star formation (z ∼ 2). We visually classify a complete sample of massive (M > 1010M⊙) galaxies at this epoch, drawn from the Cosmic Assembly Near-infrared Deep Ex…
VoIgt profile Parameter Estimation Routine (viper): H I photoionization rate at z < 0.5
Khaire, Vikram; Srianand, Raghunathan; Choudhury, Tirthankar Roy +1 more
We have developed a parallel code called the VoIgt profile Parameter Estimation Routine (viper) for automatically fitting the H I Lyα forest seen in the spectra of quasi-stellar objects (QSOs). We obtained the H I column density distribution function (CDDF) and linewidth (b) parameter distribution for z < 0.45 using spectra of 82 QSOs obtained …
On the progenitor of the Type IIb supernova 2016gkg
Treu, Tommaso; Kilpatrick, Charles D.; Foley, Ryan J. +7 more
We present a detection in pre-explosion Hubble Space Telescope (HST) imaging of a point source consistent with being the progenitor star of the Type IIb supernova (SN IIb) 2016gkg. Post-explosion imaging from the Keck adaptive optics system was used to perform relative astrometry between the Keck and HST imaging. We identify a single point source …
Evidence that the AGN dominates the radio emission in z ∼ 1 radio-quiet quasars
Jarvis, Matt J.; Kalfountzou, Eleni; White, Sarah V. +4 more
In order to understand the role of radio-quiet quasars (RQQs) in galaxy evolution, we must determine the relative levels of accretion and star-formation activity within these objects. Previous work at low radio flux densities has shown that accretion makes a significant contribution to the total radio emission, in contrast with other quasar studie…
Diamagnetic region(s): structure of the unmagnetized plasma around Comet 67P/CG
Glassmeier, K. -H.; Nilsson, H.; Carr, C. +14 more
The ESA's comet chaser Rosetta has monitored the evolution of the ionized atmosphere of comet 67P/Churyumov-Gerasimenko (67P/CG) and its interaction with the solar wind, during more than 2 yr. Around perihelion, while the cometary outgassing rate was highest, Rosetta crossed hundreds of unmagnetized regions, but did not seem to have crossed a larg…
HICOSMO - cosmology with a complete sample of galaxy clusters - I. Data analysis, sample selection and luminosity-mass scaling relation
Reiprich, T. H.; Schellenberger, G.
The X-ray regime, where the most massive visible component of galaxy clusters, the intracluster medium, is visible, offers directly measured quantities, like the luminosity, and derived quantities, like the total mass, to characterize these objects. The aim of this project is to analyse a complete sample of galaxy clusters in detail and constrain …
Evidence of sub-surface energy storage in comet 67P from the outburst of 2016 July 03
Langevin, Y.; Jorda, L.; Lamy, P. L. +67 more
On 2016 July 03, several instruments onboard ESA's Rosetta spacecraft detected signs of an outburst event on comet 67P, at a heliocentric distance of 3.32 au from the Sun, outbound from perihelion. We here report on the inferred properties of the ejected dust and the surface change at the site of the outburst. The activity coincided with the local…