Search Publications
ALMA observations of 4U 1728-34 and 4U 1820-30: first detection of neutron star X-ray binaries at 300 GHz
Díaz Trigo, M.; Rahoui, F.; Russell, D. M. +3 more
We report on the first observations of neutron star low-mass X-ray binaries with the Atacama Large Millimeter/submillimeter Array (ALMA) at 300 GHz. Quasi-simultaneous observations of 4U 1728-34 and 4U 1820-30 were performed at radio (ATCA), infrared (VLT) and X-ray (Swift) frequencies, spanning more than eight decades in frequency coverage. Both …
Atmospheric tides in Earth-like planets
Mathis, S.; Laskar, J.; Auclair-Desrotour, P.
Context. Atmospheric tides can strongly affect the rotational dynamics of planets. In the family of Earth-like planets, which includes Venus, this physical mechanism coupled with solid tides makes the angular velocity evolve over long timescales and determines the equilibrium configurations of their spin.
Aims: Unlike the solid core, the atmo…
Impact of a cometary outburst on its ionosphere. Rosetta Plasma Consortium observations of the outburst exhibited by comet 67P/Churyumov-Gerasimenko on 19 February 2016
Altwegg, K.; Tsurutani, B. T.; Nilsson, H. +15 more
We present a detailed study of the cometary ionospheric response to a cometary brightness outburst using in situ measurements for the first time. The comet 67P/Churyumov-Gerasimenko (67P) at a heliocentric distance of 2.4 AU from the Sun, exhibited an outburst at ~1000 UT on 19 February 2016, characterized by an increase in the coma surface bright…
Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15. I. Line profiles, physical conditions, and H2O abundance
Maret, S.; van Dishoeck, E. F.; Evans, N. J. +18 more
Context. Through spectrally unresolved observations of high-J CO transitions, Herschel Photodetector Array Camera and Spectrometer (PACS) has revealed large reservoirs of warm (300 K) and hot (700 K) molecular gas around low-mass protostars. The excitation and physical origin of this gas is still not understood.
Aims: We aim to shed light on …
Cosmology with the cosmic microwave background temperature-polarization correlation
Couchot, F.; Henrot-Versillé, S.; Perdereau, O. +4 more
We demonstrate that the cosmic microwave background (CMB) temperature-polarization cross-correlation provides accurate and robust constraints on cosmological parameters. We compare them with the results from temperature or polarization and investigate the impact of foregrounds, cosmic variance, and instrumental noise. This analysis makes use of th…
First detection of hydrogen in the β Pictoris gas disk
Lecavelier des Etangs, A.; Bourrier, V.; Ferlet, R. +6 more
The young and nearby star β Pictoris (β Pic) is surrounded by a debris disk composed of dust and gas known to host a myriad evaporating exocomets, planetesimals and at least one planet. At an edge-on inclination, as seen from Earth, this system is ideal for debris disk studies providing an excellent opportunity to use absorption spectroscopy to st…
Kinematics of coronal rain in a transversely oscillating loop: Ponderomotive force and rain-excited oscillations
Kohutova, P.; Verwichte, E.; Neukirch, T. +2 more
Context. Coronal rain is composed of cool dense blobs that form in solar coronal loops and are a manifestation of catastrophic cooling linked to thermal instability. Once formed, rain falls towards the solar surface at sub-ballistic speeds, which is not well understood. Pressure forces seem to be the prime candidate to explain this. In many observ…
An eccentric companion at the edge of the brown dwarf desert orbiting the 2.4 M⊙ giant star HIP 67537
Wittenmyer, R. A.; Jones, M. I.; Drass, H. +5 more
We report the discovery of a substellar companion around the giant star HIP 67537. Based on precision radial velocity measurements from CHIRON and FEROS high-resolution spectroscopic data, we derived the following orbital elements for HIP 67537 b: mb sin I = 11.1+0.4-1.1Mjup, a =4.9+0.14-…
Gaia Data Release 1. Validation of the photometry
Jordi, C.; Evans, D. W.; Brown, A. G. A. +12 more
Aims: The photometric validation of the Gaia DR1 release of the ESA Gaia mission is described and the quality of the data shown.
Methods: This is carried out via an internal analysis of the photometry using the most constant sources. Comparisons with external photometric catalogues are also made, but are limited by the accuracies and sys…
Hard X-ray variability of V404 Cygni during the 2015 outburst
Motta, S. E.; Sánchez-Fernández, C.; Kuulkers, E. +1 more
Aims: Hard X-ray spectra of black hole binaries (BHB) are produced by Comptonization of soft seed photons by hot electrons near the black hole. The slope of the resulting energy spectra is governed by two main parameters: the electron temperature (Te) and optical depth (τ) of the emitting plasma. Given the extreme brightness of V40…