Search Publications
Jupiter's ammonia distribution derived from VLA maps at 3-37 GHz
de Pater, Imke; Sault, R. J.; Wong, Michael H. +3 more
We observed Jupiter four times over a full rotation (10 h) with the upgraded Karl G. Jansky Very Large Array (VLA) between December 2013 and December 2014. Preliminary results at 4-17 GHz were presented in de Pater et al. (2016); in the present paper we present the full data set at frequencies between 3 and 37 GHz. Major findings are:
i) The …Multiplicity of Galactic Cepheids and RR Lyrae stars from Gaia DR2. II. Resolved common proper motion pairs
Mérand, Antoine; Evans, Nancy Remage; Gieren, Wolfgang +6 more
Context. The multiplicity of classical Cepheids (CCs) and RR Lyrae stars (RRLs) is still imperfectly known, particularly for RRLs.
Aims: In order to complement the close-in short orbital period systems presented in Paper I, our aim is to detect the wide, spatially resolved companions of the targets of our reference samples of Galactic CCs and…
The age of the Galactic stellar halo from Gaia white dwarfs
Hambly, N. C.; Rowell, N.; Bergeron, P. +3 more
We use 156 044 white dwarf candidates with ≥5σ significant parallax measurements from the Gaia mission to measure the velocity dispersion of the Galactic disc; (σU, σV, σW) = (30.8, 23.9, 20.0) km s-1. We identify 142 objects that are inconsistent with disc membership at the >5σ level. This is the lar…
The role of molecular filaments in the origin of the prestellar core mass function and stellar initial mass function
André, Ph.; Arzoumanian, D.; Könyves, V. +2 more
Context. The origin of the stellar initial mass function (IMF) is one of the most debated issues in astrophysics.
Aims: Here we explore the possible link between the quasi-universal filamentary structure of star-forming molecular clouds and the origin of the IMF.
Methods: Based on our recent comprehensive study of filament properties fro…
The Evolution of the He II-ionizing Background at Redshifts 2.3 < z < 3.8 Inferred from a Statistical Sample of 24 HST/COS He II Lyα Absorption Spectra
Hennawi, Joseph F.; Worseck, Gábor; Prochaska, J. Xavier +1 more
We present measurements of the large-scale (≈40 comoving Mpc) effective optical depth of He II Lyα absorption, {τ }eff}, at 2.54 < z < 3.86 toward 16 He II-transparent quasars observed with the Cosmic Origins Spectrograph on the Hubble Space Telescope, to characterize the ionization state of helium in the intergalactic medium (IGM…
Kinematics with Gaia DR2: the force of a dwarf
Anders, F.; Chiappini, C.; Santiago, B. X. +10 more
We use Gaia DR2 astrometric and line-of-sight velocity information combined with two sets of distances obtained with a Bayesian inference method to study the 3D velocity distribution in the Milky Way disc. We search for variations in all Galactocentric cylindrical velocity components (Vϕ, VR, and Vz) with Galactic …
New Constraints on the Nuclear Equation of State from the Thermal Emission of Neutron Stars in Quiescent Low-mass X-Ray Binaries
Guillot, Sebastien; Webb, Natalie; Reisenegger, Andreas +3 more
This paper presents a new analysis of the thermal emission from the neutron star (NS) surface to constrain the dense matter equation of state. We employ an empirical parameterization of the equation of state with a Markov Chain Monte Carlo approach to consistently fit the spectra of quiescent low-mass X-ray binaries in globular clusters with well-…
On the Mass Accretion Rate and Infrared Excess in Herbig Ae/Be Stars
Arun, R.; Mathew, Blesson; Manoj, P. +5 more
The present study makes use of the unprecedented capability of the Gaia mission to obtain the stellar parameters such as distance, age, and mass of HAeBe stars. The accuracy of Gaia DR2 astrometry is demonstrated from the comparison of the Gaia DR2 distances of 131 HAeBe stars with the previously estimated values from the literature. This is one o…
Universality of Lower Hybrid Waves at Earth's Magnetopause
Lavraud, B.; Génot, V.; André, M. +15 more
Waves around the lower hybrid frequency are frequently observed at Earth's magnetopause and readily reach very large amplitudes. Determining the properties of lower hybrid waves is crucial because they are thought to contribute to electron and ion heating, cross-field particle diffusion, anomalous resistivity, and energy transfer between electrons…
Gaia GraL: Gaia DR2 Gravitational Lens Systems. III. A systematic blind search for new lensed systems
Djorgovski, S. G.; Stern, D.; Surdej, J. +13 more
Aims: In this work, we aim to provide a reliable list of gravitational lens candidates based on a search performed over the entire Gaia Data Release 2 (Gaia DR2). We also aim to show that the astrometric and photometric information coming from the Gaia satellite yield sufficient insights for supervised learning methods to automatically identi…