Search Publications
Magnesium in the atmosphere of the planet HD 209458 b: observations of the thermosphere-exosphere transition region
Ehrenreich, D.; Lecavelier des Etangs, A.; Bourrier, V. +8 more
The planet HD 209458 b is one of the most well studied hot-Jupiter exoplanets. The upper atmosphere of this planet has been observed through ultraviolet/optical transit observations with H i observation of the exosphere revealing atmospheric escape. At lower altitudes just below the thermosphere, detailed observations of the Na i absorption line h…
Constraining turbulence and conduction in the hot ICM through density perturbations
Churazov, E.; Gaspari, M.
Turbulence and conduction can dramatically affect the evolution of baryons in the universe; current constraints are however rare and uncertain. Using 3D high-resolution hydrodynamic simulations, tracking both electrons and ions, we study the effects of turbulence and conduction in the hot intracluster medium. We show how the power spectrum of the …
Comparison of Kepler Photometric Variability with the Sun on Different Timescales
Basri, Gibor; Walkowicz, Lucianne M.; Reiners, Ansgar
We utilize Kepler data to study the precision differential photometric variability of solar-type and cooler stars at different timescales, ranging from half an hour to three months. We define a diagnostic that characterizes the median differential intensity change between data bins of a given timescale. We apply the same diagnostics to Solar and H…
Limits on intermediate-mass black holes in six Galactic globular clusters with integral-field spectroscopy
Kissler-Patig, M.; de Zeeuw, P. T.; Neumayer, N. +6 more
Context. The formation of supermassive black holes at high redshift still remains a puzzle to astronomers. No accretion mechanism can explain the fast growth from a stellar mass black hole to several billion solar masses in less than one Gyr. The growth of supermassive black holes becomes reasonable only when starting from a massive seed black hol…
The Size of the Narrow-line-emitting Region in the Seyfert 1 Galaxy NGC 5548 from Emission-line Variability
Kochanek, C. S.; Vestergaard, M.; Peterson, B. M. +8 more
The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n e ~ 105 cm-3) than previously supposed. The [O III] line width is consis…
One-dimensional delayed-detonation models of Type Ia supernovae: confrontation to observations at bolometric maximum
Hillier, D. John; Dessart, Luc; Blondin, Stéphane +1 more
The delayed-detonation explosion mechanism applied to a Chandrasekhar-mass white dwarf offers a very attractive model to explain the inferred characteristics of Type Ia supernovae (SNe Ia). The resulting ejecta are chemically stratified, have the same mass and roughly the same asymptotic kinetic energy, but exhibit a range in 56Ni mass.…
Distance priors from Planck and dark energy constraints from current data
Wang, Yun; Wang, Shuang
We derive distance priors from Planck first data release, and examine their impact on dark energy constraints from current observational data. We give the mean values and covariance matrix of {R,la,Ωbh2,ns}, which give an efficient summary of Planck data. The cosmic microwave background shift parameters …
Cosmology with massive neutrinos III: the halo mass function and an application to galaxy clusters
Viel, Matteo; Xia, Jun-Qing; Costanzi, Matteo +4 more
We use a suite of N-body simulations that incorporate massive neutrinos as an extra-set of particles to investigate their effect on the halo mass function. We show that for cosmologies with massive neutrinos the mass function of dark matter haloes selected using the spherical overdensity (SO) criterion is well reproduced by the fitting formula of …
The SL2S Galaxy-scale Lens Sample. III. Lens Models, Surface Photometry, and Stellar Masses for the Final Sample
Treu, Tommaso; Gavazzi, Raphaël; Marshall, Philip J. +2 more
We present Hubble Space Telescope (HST) imaging data and Canada-France-Hawaii Telescope (CFHT) near-infrared ground-based images for the final sample of 56 candidate galaxy-scale lenses uncovered in the CFHT Legacy Survey as part of the Strong Lensing in the Legacy Survey project. The new images are used to perform lens modeling, measure surface p…
HerMES: The Contribution to the Cosmic Infrared Background from Galaxies Selected by Mass and Redshift
Ivison, R. J.; Yun, M. S.; Scott, D. +28 more
We quantify the fraction of the cosmic infrared background (CIB) that originates from galaxies identified in the UV/optical/near-infrared by stacking 81,250 (~35.7 arcmin-2) K-selected sources (K AB < 24.0) split according to their rest-frame U - V versus V - J colors into 72,216 star-forming and 9034 quiescent galaxies, o…