Search Publications
Far-ultraviolet Variable Sources in M31
Leahy, Denis; Buick, Megan; Postma, Joseph +1 more
The Ultraviolet Imaging Telescope (UVIT) on board the AstroSat observatory has imaged the Andromeda galaxy (M31) from 2017 to 2019 in the far- and near-UV (FUV and NUV) with the high spatial resolution of ≃1″. The survey covered the large sky area of M31 with a set of observations (Fields), each 28' in diameter. Field 1 was observed in two epochs …
A Spectroscopic Study of Supernova Remnants with the Infrared Space Observatory
Rho, Jeonghee; Ravi, Aravind P.; Park, Sangwook +1 more
We present far-infrared (FIR) spectroscopy of supernova remnants (SNRs) based on the archival data of the Infrared Space Observatory taken with the Long Wavelength Spectrometer (LWS). Our sample includes previously unpublished profiles of line and continuum spectra for 20 SNRs in the Galaxy and Magellanic Clouds. In several SNRs including G21.5-0.…
Data reduction and calibration accuracy of the imaging Fourier transform spectrometer SITELLE
Prunet, S.; Drissen, L.; Martin, T.
SITELLE, an imaging Fourier Transform Spectrometer, is part of the Canada-France-Hawaii instrument suite. It delivers spectral cubes covering an 11 arcmin × 11 arcmin field of view with a seeing-limited spatial resolution and a tunable spectral resolution (R ~ 1-10 000) in selected bands of the visible range (350-900 nm). We present a complete pic…
Dynamically produced moving groups in interacting simulations
Craig, Peter; Chakrabarti, Sukanya; Quillen, Alice +1 more
We show that smoothed particle hydrodynamics (SPH) simulations of dwarf galaxies interacting with a Milky Way-like disc produce moving groups in the simulated stellar disc. We analyse three different simulations: one that includes dwarf galaxies that mimic the Large Magellanic Cloud, Small Magellanic Cloud, and the Sagittarius dwarf spheroidal; an…
Kronoseismology V: A panoply of waves in Saturn's C ring driven by high-order internal planetary oscillations
Nicholson, Philip D.; French, Richard G.; Hedman, Matthew M. +3 more
Saturn's rings act as a system of innumerable test particles that are remarkably sensitive to periodic disturbances in the planet's gravitational field. We identify 15 additional density and bending waves in Saturn's C ring driven by the planet's internal normal mode oscillations. The collective response of the rings to Saturn's oscillations resul…
Application of a new X-ray reflection model to V1223 Sagittarii
Ishida, Manabu; Hayashi, Takayuki; Kitaguchi, Takao
In intermediate polars (IPs), the intrinsic thermal emissions from white dwarfs (WDs) have typically been studied. Few reports have analysed X-ray reflections from WDs. We recently developed an elaborate IP-reflection spectral model. Herein, we report the first application of a reflection model with an IP thermal model to the spectra of the bright…
Updated values of solar gravitational moments J2n using HMI helioseismic inference of internal rotation
Meftah, M.; Mecheri, R.
The solar gravitational moments J2n are important astronomical quantities whose precise determination is relevant for solar physics, gravitational theory and high precision astrometry, and celestial mechanics. Accordingly, we propose in the present work to calculate new values of J2n (for n = 1, 2, 3, 4, and 5) using recent t…
Solar Orbiter's first Venus flyby. MAG observations of structures and waves associated with the induced Venusian magnetosphere
Maksimovic, M.; Bale, S. D.; Horbury, T. S. +18 more
Context. The induced magnetosphere of Venus is caused by the interaction of the solar wind and embedded interplanetary magnetic field with the exosphere and ionosphere of Venus. Solar Orbiter entered Venus's magnetotail far downstream, > 70 Venus radii, of the planet and exited the magnetosphere over the north pole. This offered a unique view o…
Nonlinear Magnetic Gradients and Complete Magnetic Geometry From Multispacecraft Measurements
Russell, C. T.; Rong, Zhaojin; Shen, Chao +8 more
Topological configurations of the magnetic field play key roles in the dynamics of space plasmas. This study presents a novel algorithm that can estimate the quadratic magnetic gradient as well as the complete geometrical features of magnetic field lines, based on magnetic field and current density measurements by a multiple spacecraft constellati…
BAT99-9 - a WC4 Wolf-Rayet star with nitrogen emission: evidence for binary evolution?
Aadland, Erin; Massey, Philip; Hillier, D. John +1 more
An analysis of the Large Magellanic Cloud (LMC) WC4 star BAT99-9 (HD 32125, FD 4, Brey 7, WS 3) shows that the star still contains photospheric nitrogen. Three N emission features (N V λλ1238, 1242, N IV λ1719, and N IV λλ3479-3485) are unambiguously identified in the spectrum. CMFGEN models of the star yield an N/C ratio of 0.004 ± 0.002 (by numb…