Search Publications
Signatures of the resonances of a large Galactic bar in local velocity space
Monari, G.; Siebert, A.; Famaey, B. +2 more
The second data release of the Gaia mission has revealed a very rich structure in local velocity space. In terms of in-plane motions, this rich structure is also seen as multiple ridges in the actions of the axisymmetric background potential of the Galaxy. These ridges are probably related to a combination of effects from ongoing phase-mixing and …
ALMA Unveils Widespread Molecular Gas Clumps in the Ram Pressure Stripped Tail of the Norma Jellyfish Galaxy
Fumagalli, Michele; Brinks, Elias; Combes, Françoise +8 more
We present the first high-resolution map of the cold molecular gas distribution as traced by CO(2-1) emission with ALMA in a long ram pressure stripped tail. The Norma cluster galaxy ESO 137-001 is undergoing a strong interaction with the surrounding intracluster medium and is one of the nearest jellyfish galaxies with a long multiphase and multic…
The Herschel Dwarf Galaxy Survey. II. Physical conditions, origin of [C II] emission, and porosity of the multiphase low-metallicity ISM
Lebouteiller, V.; Madden, S. C.; Galliano, F. +7 more
The sensitive infrared telescopes, Spitzer and Herschel, have been used to target low-metallicity star-forming galaxies, allowing us to investigate the properties of their interstellar medium (ISM) in unprecedented detail. Interpretation of the observations in physical terms relies on careful modeling of those properties. We have employed a multip…
Using Gaia DR2 to constrain local dark matter density and thin dark disk
Buch, Jatan; Leung, John Shing Chau; Fan, JiJi
We use stellar kinematics from the latest Gaia data release (DR2) to measure the local dark matter (DM) density ρDM in a heliocentric cylinder of radius R= 150 pc and half-height z= 200 pc. We also explore the prospect of using our analysis to estimate the DM density in local substructure by setting constraints on the surface density an…
BAT AGN Spectroscopic Survey. XI. The Covering Factor of Dust and Gas in Swift/BAT Active Galactic Nuclei
Ueda, Yoshihiro; Kawamuro, Taiki; Ricci, Claudio +10 more
We quantify the luminosity contribution of active galactic nuclei (AGNs) to the 12 µm, mid-infrared (MIR; 5-38 µm), and total IR (5-1000 µm) emission in the local AGNs detected in the all-sky 70 month Swift/Burst Alert Telescope (BAT) ultrahard X-ray survey. We decompose the IR spectral energy distributions (SEDs) of 587 objects …
A rapidly changing jet orientation in the stellar-mass black-hole system V404 Cygni
Soria, Roberto; Sarazin, Craig L.; Jonker, Peter G. +18 more
Powerful relativistic jets are one of the main ways in which accreting black holes provide kinetic feedback to their surroundings. Jets launched from or redirected by the accretion flow that powers them are expected to be affected by the dynamics of the flow, which for accreting stellar-mass black holes has shown evidence for precession1
The ultra-diffuse galaxy NGC 1052-DF2 with MUSE. I. Kinematics of the stellar body
Emsellem, Eric; Müller, Oliver; Lelli, Federico +14 more
The so-called ultra-diffuse galaxy NGC 1052-DF2 was announced to be a galaxy lacking dark matter based on a spectroscopic study of its constituent globular clusters. Here we present the first spectroscopic analysis of the stellar body of this galaxy using the MUSE integral-field spectrograph at the (ESO) Very Large Telescope. The MUSE datacube sim…
The gravitational force field of the Galaxy measured from the kinematics of RR Lyrae in Gaia
Gerhard, Ortwin; Wegg, Christopher; Bieth, Marie
From a sample of 15651 RR Lyrae with accurate proper motions in Gaia DR2, we measure the azimuthally averaged kinematics of the inner stellar halo between 1.5 and 20 kpc from the Galactic centre. We find that their kinematics are strongly radially anisotropic, and their velocity ellipsoid nearly spherically aligned over this volume. Only in the in…
The Optical Afterglow of GW170817: An Off-axis Structured Jet and Deep Constraints on a Globular Cluster Origin
Berger, E.; Chornock, R.; Laskar, T. +25 more
We present a revised and complete optical afterglow light curve of the binary neutron star merger GW170817, enabled by deep Hubble Space Telescope (HST) F606W observations at ≈584 days post-merger, which provide a robust optical template. The light curve spans ≈110-362 days, and is fully consistent with emission from a relativistic structured jet …
The halo's ancient metal-rich progenitor revealed with BHB stars
Belokurov, Vasily; Evans, N. Wyn; Koposov, Sergey E. +2 more
Using the data from the Sloan Digital Sky Survey and the Gaia satellite, we assemble a pure sample of ∼3000 blue horizontal branch (BHB) stars with 7D information, including positions, velocities, and metallicities. We demonstrate that, as traced with BHBs, the Milky Way's stellar halo is largely unmixed and cannot be well represented with a conve…