Search Publications
Efficient kinetic Lattice Boltzmann simulation of three-dimensional Hall-MHD turbulence
Telloni, Daniele; Marino, Raffaele; Foldes, Raffaello +4 more
Simulating plasmas in the Hall-magnetohydrodynamics (Hall-MHD) regime represents a valuable approach for the investigation of complex nonlinear dynamics developing in astrophysical frameworks and fusion machines. The Hall electric field is computationally very challenging as it involves the integration of an additional term, proportional to \nabla…
NY Bootes: An Active Deep and Low-mass-ratio Contact Binary with a Cool Companion in a Hierarchical Triple System
Meng, Fangbin; Zhu, Liying; Qian, Shengbang +3 more
The first detailed photometric and spectroscopic study of G-type short-period binary NY Boo is presented. The radial velocity curve was obtained by the cross-correlation function (CCF) method based on LAMOST and SDSS spectra, which derived its mass ratio as q = 0.139(1/7.2). The CCF profiles of the SDSS spectra clearly show the existence of a cool…
XMM-Newton Detection of X-Ray Emission from the Metal-polluted White Dwarf G 29-38
Chu, Y. -H.; Estrada-Dorado, S.; Guerrero, M. A. +3 more
A recent analysis of Chandra X-ray data of the metal-polluted white dwarf G 29-38 has revealed X-ray emission that can be attributed to the accretion of debris from a planetary body. In the light of this detection we revisit here archival XMM-Newton observations of G 29-38 from which only an upper limit was derived in the past due to the presence …
Newly Discovered Wolf-Rayet Stars in M31
Massey, Philip; Neugent, Kathryn F.
The evolved massive star populations of the Local Group galaxies are generally thought to be well understood. However, recent work has suggested that the Wolf-Rayet (WR) content of M31 may have been underestimated. We therefore began a pilot project to search for new WRs in M31 and to reexamine the completeness of our previous WR survey, finished …
An inner warp discovered in the disk around HD 110058 using VLT/SPHERE and HST/STIS
Ménard, F.; Milli, J.; Boccaletti, A. +16 more
Context. An edge-on debris disk was detected in 2015 around the young, nearby A0V star HD 110058. The disk showed features resembling those seen in the disk of β Pictoris that could indicate the presence of a perturbing planetary-mass companion in the system.
Aims: We investigated new and archival scattered light images of the disk in order t…
Detecting planetary mass companions near the water frost-line using JWST interferometry
Carter, Aarynn L.; Hinkley, Sasha; Sallum, Steph +4 more
JWST promises to be the most versatile infrared observatory for the next two decades. The Near Infrared and Slitless Spectrograph (NIRISS) instrument, when used in the Aperture Masking Interferometry (AMI) mode, will provide an unparalleled combination of angular resolution and sensitivity compared to any existing observatory at mid-infrared wavel…
Determining satellite infall times using machine learning
Cautun, Marius; Barmentloo, Stan
A key unknown of the Milky Way (MW) satellites is their orbital history, and, in particular, the time they were accreted onto the MW system since it marks the point where they experience a multitude of environmental processes. We present a new methodology for determining infall times, namely using a neural network (NN) algorithm. The NN is trained…
Sulfur abundances in three Galactic clusters: Ruprecht 106, Trumpler 5, and Trumpler 20
Bonifacio, P.; Caffau, E.; Monaco, L. +4 more
Context. Sulfur (S) is one of the lesser-studied α-elements. Published investigations of its behavior have so far focused on local stars, and only a few clusters of the Milky Way have been considered to study this topic. We aim to study the S content of the globular cluster Ruprecht 106 - which has never before been studied for this purpose, but i…
Spectra of V1405 Cas at the Very Beginning Indicate a Low-mass ONeMg White Dwarf Progenitor
Maehara, Hiroyuki; Nogami, Daisaku; Yamanaka, Masayuki +9 more
The lowest possible mass of ONeMg white dwarfs (WDs) has not been clarified despite its importance in the formation and evolution of WDs. We tackle this issue by studying the properties of V1405 Cas (Nova Cassiopeiae 2021), which is an outlier given a combination of its very slow light-curve evolution and the recently reported neon-nova identifica…
The blue supergiant Sher 25 revisited in the Gaia era
Butler, K.; Weßmayer, D.; Przybilla, N. +2 more
Aims: The evolutionary status of the blue supergiant Sher 25 and its membership to the massive cluster NGC 3603 are investigated.
Methods: A hybrid non-local thermodynamic equilibrium (non-LTE) spectrum synthesis approach is employed to analyse a high-resolution optical spectrum of Sher 25 and five similar early B-type comparison stars i…