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Concept

Rayon de Schwarzschild

Publications associées (21)

Stellar Metallicities and Gradients in the Isolated, Quenched Low-mass Galaxy Tucana

Nicolas Lawrence Etienne Longeard

We measure the metallicities of 374 red giant branch (RGB) stars in the isolated, quenched dwarf galaxy Tucana using Hubble Space Telescope (HST) narrow-band (F395N) Calcium H & K (CaHK) imaging. Our sample is a factor of similar to 7 similar to 7 larger t ...

Iop Publishing Ltd2024

A model for the infrared-radio correlation of main sequence galaxies at gigahertz frequencies and its variation with redshift and stellar mass

Salim Bennouna, Mark Thomas Sargent

Context. The infrared-radio correlation (IRRC) of star-forming galaxies can be used to estimate their star formation rate (SFR) based on the radio continuum luminosity at MHz-GHz frequencies. For its practical application in future deep radio surveys, it i ...

Edp Sciences S A2023

LensWatch. I. Resolved HST Observations and Constraints on the Strongly Lensed Type Ia Supernova 2022qmx ("SN Zwicky")

Frédéric Courbin

Supernovae (SNe) that have been multiply imaged by gravitational lensing are rare and powerful probes for cosmology. Each detection is an opportunity to develop the critical tools and methodologies needed as the sample of lensed SNe increases by orders of ...

IOP Publishing Ltd2023

Uncovering a population of gravitational lens galaxies with magnified standard candle SN Zwicky

Cameron Alexander Campbell Lemon, Johannes Richard Cornelis Geerit Kruis, Rémy Elie Joseph

Detecting gravitationally lensed supernovae is among the biggest challenges in astronomy. It involves a combination of two very rare phenomena: catching the transient signal of a stellar explosion in a distant galaxy and observing it through a nearly perfe ...

NATURE PORTFOLIO2023

The ellipticity parameterization for an NFW profile: An overlooked angular structure in strong lens modeling

Frédéric Courbin

Galaxy-scale gravitational lenses are often modeled with two-component mass profiles where one component represents the stellar mass and the second is a Navarro Frenk White (NFW) profile representing the dark matter. Outside of the spherical case, the NFW ...

Edp Sciences S A2023

Strong gravitational lensing by AGNs as a probe of the quasar-host relations in the distant Universe

Frédéric Courbin, Malte Tewes, Martin Raoul Robert Millon, Aymeric Alexandre Galan

A rare case of a quasar acting as a gravitational lens allows a precise determination of the mass of the quasar's host galaxy and offers a new path to studying the connections between supermassive black holes and their host galaxies. ...

NATURE PORTFOLIO2023

Non-perturbative probability distribution function for cosmological counts in cells

Sergey Sibiryakov, Mikhail Ivanov

We present a non-perturbative calculation of the 1-point probability distribution function (PDF) for the spherically-averaged matter density field. The PDF is represented as a path integral and is evaluated using the saddle-point method. It factorizes into ...

IOP PUBLISHING LTD2019

The Sloan Digital Sky Survey Reverberation Mapping Project: Initial CIV Lag Results from Four Years of Data

Jean-Paul Richard Kneib, Feng Li

We present reverberation-mapping (RM) lags and black hole mass measurements using the C IV lambda 1549 broad emission line from a sample of 348 quasars monitored as a part of the Sloan Digital Sky Survey RM Project. Our data span four years of spectroscopi ...

IOP PUBLISHING LTD2019

Precision theoretical methods for large-scale structure of the Universe

Mikhail Ivanov

We develop new analytic methods to accurately describe the formation of cosmic large-scale structure. These methods are based on the path integral formalism and allows one to efficiently address a number of long-standing problems in the field. We describe ...

EPFL2019

Survey of gravitationally-lensed objects in HSC imaging (SuGOHI) III. Statistical strong lensing constraints on the stellar IMF of CMASS galaxies

Hung-Hsu Chan

Context. The determination of the stellar initial mass function (IMF) of massive galaxies is one of the open problems in cosmology. Strong gravitational lensing is one of the few methods that allow us to constrain the IMF outside of the Local Group. Aims. ...

2019

Models of the strongly lensed quasar DES J0408-5354

Frédéric Courbin, Georges Meylan, Eduardo Sanchez, Hung-Hsu Chan, Vivien François Bonvin, Cameron Alexander Campbell Lemon

We present detailed modelling of the recently discovered, quadruply lensed quasar J0408-5354, with the aim of interpreting its remarkable configuration: besides three quasar images (A, B, D) around the main deflector (G1), a fourth image (C) is significant ...

Oxford Univ Press2017

Discovery of two gravitationally lensed quasars in the Dark Energy Survey

Yi Zhang, Frédéric Courbin, Georges Meylan, Eduardo Sanchez

We present spectroscopic confirmation of two new gravitationally lensed quasars, discovered in the Dark Energy Survey (DES) and Wide-field Infrared Survey Explorer (WISE) based on their multiband photometry and extended morphology in DES images. Images of ...

Oxford Univ Press2015

Understanding The Unique Assembly History Of Central Group Galaxies

Jean-Paul Richard Kneib

Central galaxies (CGs) in massive halos live in unique environments with formation histories closely linked to that of the host halo. In local clusters, they have larger sizes (R-e) and lower velocity dispersions (sigma) at fixed stellar mass M-*, and much ...

American Astronomical Society2014

Planck 2013 results. XXVI. Background geometry and topology of the Universe

Julien Lesgourgues, Jason Douglas McEwen

The new cosmic microwave background (CMB) temperature maps from Planck provide the highest-quality full-sky view of the surface of last scattering available to date. This allows us to detect possible departures from the standard model of a globally homogen ...

Edp Sciences S A2014

Evidence for major mergers of galaxies at 2 less than or similar to z < 4 in the VVDS and VUDS surveys

Jean-Paul Richard Kneib

Context. The mass assembly of galaxies can proceed through different physical processes. Here we report on the spectroscopic identification of close physical pairs of galaxies at redshifts 2 less than or similar to z < 4 and discuss the impact of major mer ...

EDP Sciences2014

Hole and notch sensitivity of aluminium replicated foam

Andreas Mortensen, Andreas Rossoll

The flow and failure behaviour of replicated pure aluminium foams in the presence of holes and notches is explored, varying the pore size and the notch depth or hole radius. Flat dog-bone tensile specimens containing a cylindrical hole, and cylindrical V-n ...

Elsevier2011

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

Frédéric Courbin, Georges Meylan, Yves Revaz, Malte Tewes

We present accurate time delays for the quadruply imaged quasar HE 0435-1223. The delays were measured from 575 independent photometric points obtained in the R-band between January 2004 and March 2010. With seven years of data, we clearly show that quasar ...

2011

First case of strong gravitational lensing by a QSO: SDSS J0013+1523 at z=0.120

Frédéric Courbin, Georges Meylan, Malte Tewes, François Henri Ambroise Rérat

We present the first case of strong gravitational lensing by a QSO: SDSS J0013 + 1523 at z = 0.120. The discovery is the result of a systematic search for emission lines redshifted behind QSOs, among 22 298 spectra of the SDSS data release 7. Apart from th ...

2010

The fundamental plane of EDisCS galaxies The effect of size evolution

Pascale Jablonka

We study the evolution of spectral early-type galaxies in clusters, groups, and the field up to redshift 0.9 using the ESO Distant Cluster Survey (EDisCS) dataset. We measure structural parameters (circularized half-luminosity radii R-e, surface brightness ...

2010

Black hole bound on the number of species and quantum gravity at CERN LHC

In theories with a large number N of particle species, black hole physics imposes an upper bound on the mass of the species equal to M-Planck/root N. This bound suggests a novel solution to the hierarchy problem in which there are N approximate to 10(32) g ...

American Physical Society2008