Search Publications
H0LiCOW VII: cosmic evolution of the correlation between black hole mass and host galaxy luminosity
Treu, Tommaso; Auger, Matthew W.; Morishita, Takahiro +8 more
Strongly lensed active galactic nuclei (AGN) provide a unique opportunity to make progress in the study of the evolution of the correlation between the mass of supermassive black holes (M_BH) and their host galaxy luminosity (Lhost). We demonstrate the power of lensing by analysing two systems for which state-of-the-art lens modelling t…
Gravitationally lensed quasars in Gaia: I. Resolving small-separation lenses
McMahon, Richard G.; Auger, Matthew W.; Koposov, Sergey E. +1 more
Gaia's exceptional resolution (FWHM ∼ 0.1 arcsec) allows identification and cataloguing of the multiple images of gravitationally lensed quasars. We investigate a sample of 49 known lensed quasars in the Sloan Digital Sky Survey (SDSS) footprint, with image separations less than 2 arcsec, and find that eight are detected with multiple components i…
Thermal modelling of water activity on comet 67P/Churyumov-Gerasimenko with global dust mantle and plural dust-to-ice ratio
Jorda, L.; Lamy, P. L.; Lara, L. M. +51 more
We perform a thermo-physical analysis on water activity of comet 67P/Churyumov-Gerasimenko (67P). The sublimation of water is assumed to occur from beneath a global, desiccated dust mantle over the irregular-shaped nucleus. The concept of two thermal models, the recipe of model formulation and the strategy of application to comet 67P are described…
An infrared view of AGN feedback in a type-2 quasar: the case of the Teacup galaxy
Villar-Martín, M.; Ramos Almeida, C.; Piqueras López, J. +1 more
We present near-infrared integral field spectroscopy data obtained with Very Large Telescope/Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) of 'the Teacup galaxy'. The nuclear K-band (1.95-2.45 µm) spectrum of this radio-quiet type-2 quasar reveals a blueshifted broad component of FWHM ∼ 1600-1800 km s-1
Constraining the dark energy equation of state using Bayes theorem and the Kullback-Leibler divergence
Hobson, M. P.; Lasenby, A. N.; Hee, S. +2 more
Data-driven model-independent reconstructions of the dark energy equation of state w(z) are presented using Planck 2015 era cosmic microwave background, baryonic acoustic oscillations (BAO), Type Ia supernova (SNIa) and Lyman α (Lyα) data. These reconstructions identify the w(z) behaviour supported by the data and show a bifurcation of the equatio…
Precise surface gravities of δ Scuti stars from asteroseismology
Reese, D. R.; Garrido, R.; Martín-Ruiz, S. +8 more
The work reported here demonstrates that it is possible to accurately determine surface gravities of δ Scuti (δ Sct) stars using the frequency content from high-precision photometry and a measurement of the parallax. Using a sample of 10 eclipsing binary systems with a δ Sct component and the unique δ Sct star discovered with a transiting planet, …
Reconstructing the high-energy irradiation of the evaporating hot Jupiter HD 209458b
Wheatley, Peter J.; Louden, Tom; Briggs, Kevin
The atmosphere of the exoplanet HD 209458b is undergoing sustained mass loss, believed to be caused by X-ray and extreme-ultraviolet (XUV) irradiation from its star. The majority of this flux is not directly observable due to interstellar absorption, but is required in order to correctly model the photoevaporation of the planet and photoionization…
Revealing structure and evolution within the corona of the Seyfert galaxy I Zw 1
Brandt, W. N.; Kriss, G. A.; Costantini, E. +3 more
X-ray spectral timing analysis is presented of XMM-Newton observations of the narrow-line Seyfert 1 galaxy I Zwicky 1 taken in 2015 January. After exploring the effect of background flaring on timing analyses, X-ray time lags between the reflection-dominated 0.3-1.0 keV energy and continuum-dominated 1.0-4.0 keV band are measured, indicative of re…
Staying away from the bar: the local dynamical signature of slow and fast bars in the Milky Way
Siebert, Arnaud; Famaey, Benoit; Bienaymé, Olivier +3 more
Both the three-dimensional density of red clump giants and the gas kinematics in the inner Galaxy indicate that the pattern speed of the Galactic bar could be much lower than previously estimated. Here, we show that such slow bar models are unable to reproduce the bimodality observed in local stellar velocity space. We do so by computing the respo…
Powerful outflows in the central parsecs of the low-luminosity active galactic nucleus NGC 1386
Prieto, M. A.; Luque, R.; Müller-Sánchez, F. +3 more
Low-luminosity active galactic nuclei, I.e. L_{bol}/Ledd ∼ 10-6-10-3, constitute the bulk population of active galactic nuclei (AGNs). Powerful jets, common in these objects, are a crucial source of feedback energy-driving mass outflows into the host galaxy and the intergalactic medium. This paper reports the first…