Search Publications
The scattering phase function of comet 67P/Churyumov-Gerasimenko coma as seen from the Rosetta/OSIRIS instrument
Jorda, L.; Lara, L. M.; Bertaux, J. -L. +52 more
The study of dust, the most abundant material in cometary nuclei, is pivotal in understanding the original materials forming the Solar system. Measuring the coma phase function provides a tool to investigate the nature of cometary dust. Rosetta/OSIRIS sampled the coma phase function of comet 67P/Churyumov-Gerasimenko, covering a large phase angle …
Dust mass distribution around comet 67P/Churyumov-Gerasimenko determined via parallax measurements using Rosetta's OSIRIS cameras
Jorda, L.; Lara, L. M.; Bertaux, J. -L. +50 more
The OSIRIS (optical, spectroscopic and infrared remote imaging system) instrument on board the ESA Rosetta spacecraft collected data of 67P/Churyumov-Gerasimenko for over 2 yr. OSIRIS consists of two cameras, a Narrow Angle Camera and a Wide Angle Camera. For specific imaging sequences related to the observation of dust aggregates in 67P's coma, t…
Probing the geometry and motion of AGN coronae through accretion disc emissivity profiles
Gallo, L. C.; Wilkins, D. R.; Gonzalez, A. G.
To gain a better understanding of the inner disc region that comprises active galactic nuclei, it is necessary to understand the pattern in which the disc is illuminated (the emissivity profile) by X-rays emitted from the continuum source above the black hole (corona). The differences in the emissivity profiles produced by various corona geometrie…
The resolved stellar populations around 12 Type IIP supernovae
Maund, Justyn R.
Core-collapse supernovae (SNe) are found in regions associated with recent massive star formation. The stellar population observed around the location of a SN can be used as a probe of the origins of the progenitor star. We apply a Bayesian mixture model to fit isochrones to the massive star population around 12 Type IIP SNe, for which constraints…
Spatially resolved variations of the IMF mass normalization in early-type galaxies as probed by molecular gas kinematics
Davis, Timothy A.; McDermid, Richard M.
We here present the first spatially resolved study of the initial mass function (IMF) in external galaxies derived using a dynamical tracer of the mass-to-light ratio (M/L). We use the kinematics of relaxed molecular gas discs in seven early-type galaxies (ETGs) selected from the ATLAS3D survey to dynamically determine M/L gradients. Th…
Joint constraints on the Galactic dark matter halo and Galactic Centre from hypervelocity stars
Sari, R.; Marchetti, T.; Rossi, Elena M. +2 more
The mass assembly history of the Milky Way can inform both theory of galaxy formation and the underlying cosmological model. Thus, observational constraints on the properties of both its baryonic and dark matter contents are sought. Here, we show that hypervelocity stars (HVSs) can in principle provide such constraints. We model the observed veloc…
Halogens as tracers of protosolar nebula material in comet 67P/Churyumov-Gerasimenko
Neefs, Eddy; Mall, Urs; De Keyser, Johan +26 more
We report the first in situ detection of halogens in a cometary coma, that of 67P/Churyumov-Gerasimenko. Neutral gas mass spectra collected by the European Space Agency's Rosetta spacecraft during four periods of interest from the first comet encounter up to perihelion indicate that the main halogen-bearing compounds are HF, HCl and HBr. The bulk …
Witnessing galaxy assembly in an extended z≈3 structure
Prochaska, J. Xavier; Rafelski, Marc; Fumagalli, Michele +9 more
We present new observations acquired with the Multi Unit Spectroscopic Explorer instrument on the Very Large Telescope in a quasar field that hosts a high column density damped Lyα absorber (DLA) at z ≈ 3.25. We detect Lyα emission from a nebula at the redshift of the DLA with line luminosity (27 ± 1) × 1041 erg s- 1, which e…
The relationship between star formation activity and galaxy structural properties in CANDELS and a semi-analytic model
Barro, Guillermo; Bell, Eric F.; Ferguson, Henry C. +13 more
We study the correlation of galaxy structural properties with their location relative to the SFR-M* correlation, also known as the star formation `star-forming main sequence' (SFMS), in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and Galaxy and Mass Assembly Survey and in a semi-analytic model (SAM) of galaxy form…
CoMaLit - V. Mass forecasting with proxies: method and application to weak lensing calibrated samples
Sereno, Mauro; Ettori, Stefano
Mass measurements of astronomical objects are most wanted but still elusive. We need them to trace the formation and evolution of cosmic structure but we can get direct measurements only for a minority. This lack can be circumvented with a proxy and a scaling relation. The twofold goal of estimating the unbiased relation and finding the right prox…