Search Publications
Testing quasar unification: radiative transfer in clumpy winds
Knigge, C.; Long, K. S.; Sim, S. A. +3 more
Various unification schemes interpret the complex phenomenology of quasars and luminous active galactic nuclei (AGN) in terms of a simple picture involving a central black hole, an accretion disc and an associated outflow. Here, we continue our tests of this paradigm by comparing quasar spectra to synthetic spectra of biconical disc wind models, p…
SPIDERS: the spectroscopic follow-up of X-ray selected clusters of galaxies in SDSS-IV
Zhang, Y. -Y.; Finoguenov, A.; Kneib, J. -P. +17 more
SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a programme dedicated to the homogeneous and complete spectroscopic follow-up of X-ray active galactic nuclei and galaxy clusters over a large area (∼7500 deg2) of the extragalactic sky. SPIDERS is part of the Sloan Digital Sky Survey (SDSS)-IV project, together with the E…
Short-term X-ray spectral variability of the quasar PDS 456 observed in a low-flux state
Tombesi, F.; Reeves, J. N.; Braito, V. +4 more
We present a detailed analysis of a recent, 2013 Suzaku campaign on the nearby (z = 0.184) luminous (Lbol ∼ 1047 erg s-1) quasar PDS 456. This consisted of three observations, covering a total duration of ∼1 Ms and a net exposure of 455 ks. During these observations, the X-ray flux was unusually low, suppressed by …
SHARP - II. Mass structure in strong lenses is not necessarily dark matter substructure: a flux ratio anomaly from an edge-on disc in B1555+375
Vegetti, S.; McKean, J. P.; Auger, M. W. +5 more
Gravitational lens flux-ratio anomalies provide a powerful technique for measuring dark matter substructure in distant galaxies. However, before using these flux-ratio anomalies to test galaxy formation models, it is imperative to ascertain that the given anomalies are indeed due to the presence of dark matter substructure and not due to some othe…
Probing the cool interstellar and circumgalactic gas of three massive lensing galaxies at z = 0.4-0.7
Zahedy, Fakhri S.; Chen, Hsiao-Wen; Rauch, Michael +2 more
We present multisightline absorption spectroscopy of cool gas around three lensing galaxies at z = 0.4-0.7. These lenses have half-light radii re = 2.6-8 kpc and stellar masses of log M*/M⊙ = 10.9-11.4, and therefore resemble nearby passive elliptical galaxies. The lensed QSO sightlines presented here occur at proj…
Acceleration of individual, decimetre-sized aggregates in the lower coma of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P. L.; Lara, L. M. +41 more
We present observations of decimetre-sized, likely ice-containing aggregates ejected from a confined region on the surface of comet 67P/Churyumov-Gerasimenko. The images were obtained with the narrow angle camera of the Optical, Spectroscopic, and Infrared Remote Imaging System on board the Rosetta spacecraft in 2016 January when the comet was at …
The SCUBA-2 Cosmology Legacy Survey: galaxies in the deep 850 µm survey, and the star-forming `main sequence'
Bowler, R. A. A.; McLure, R. J.; Dunlop, J. S. +14 more
We investigate the properties of the galaxies selected from the deepest 850-µm survey undertaken to date with (Submillimetre Common-User Bolometer Array 2) SCUBA-2 on the James Clerk Maxwell Telescope as part of the SCUBA-2 Cosmology Legacy Survey. A total of 106 sources (>5σ) were uncovered at 850 µm from an area of ≃150 arcmin
A robust measurement of the mass outflow rate of the galactic outflow from NGC 6090
Chisholm, John; Leitherer, Claus; Tremonti Christy, A. +1 more
To evaluate the impact of stellar feedback, it is critical to estimate the mass outflow rates of galaxies. Past estimates have been plagued by uncertain assumptions about the outflow geometry, metallicity, and ionization fraction. Here we use Hubble Space Telescope ultraviolet spectroscopic observations of the nearby starburst NGC 6090 to demonstr…
Cosmochemical implications of CONSERT permittivity characterization of 67P/CG
Lasue, J.; Quirico, E.; Kofman, W. +7 more
Analysis of the propagation of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) signal throughout the small lobe of the 67P/CG nucleus has permitted us to deduce the real part of the permittivity, at a value of 1.27 ± 0.05. The first interpretation of this value, using the dielectric properties of mixtures of ices (H2…
A PSF-based approach to Kepler/K2 data - I. Variability within the K2 Campaign 0 star clusters M 35 and NGC 2158
Bedin, L. R.; Piotto, G.; Nardiello, D. +1 more
Kepler and K2 data analysis reported in the literature is mostly based on aperture photometry. Because of Kepler's large, undersampled pixels and the presence of nearby sources, aperture photometry is not always the ideal way to obtain high-precision photometry, and, because of this, the data set has not been fully exploited so far. We present a n…