Search Publications
The Double Dust Envelopes of R Coronae Borealis Stars
Evans, A.; Clayton, Geoffrey C.; Matsuura, M. +5 more
The study of extended, cold dust envelopes surrounding R Coronae Borealis (RCB) stars began with their discovery by the Infrared Astronomical Satellite. RCB stars are carbon-rich supergiants characterized by their extreme hydrogen deficiency and their irregular and spectacular declines in brightness (up to 9 mag). We have analyzed new and archival…
Discovery of a 23.8 h QPO in the Swift light curve of XMMU J134736.6+173403
Jin, C.; Carpano, S.
XMMU J134736.6+173403 is an X-ray source discovered serendipitously by XMM-Newton, which was found to be spatially coincident with a pair of galaxies, including a Seyfert 2 galaxy, but presented in 2003 a very sharp persistent flux drop of a factor of 6.5 within 1 h. From the analysis of a set of 29 Swift observations conducted from 2008 February …
PSFGAN: a generative adversarial network system for separating quasar point sources and host galaxy light
Stark, Dominic; Launet, Barthelemy; Schawinski, Kevin +7 more
The study of unobscured active galactic nuclei (AGN) and quasars depends on the reliable decomposition of the light from the AGN point source and the extended host galaxy light. The problem is typically approached using parametric fitting routines using separate models for the host galaxy and the point spread function (PSF). We present a new appro…
An outflow in the Seyfert ESO 362-G18 revealed by Gemini-GMOS/IFU observations
Robinson, Andrew; Fischer, Travis C.; Schnorr-Müller, Allan +14 more
We present two-dimensional stellar and gaseous kinematics of the inner 0.7 × 1.2 kpc2 of the Seyfert 1.5 galaxy ESO 362-G18, derived from optical (4092-7338 Å) spectra obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of ≈170 pc and spectral resolution of 36 km s-1. ESO 3…
Seasonal evolution of C2N2, C3H4, and C4H2 abundances in Titan's lower stratosphere
Irwin, P. G. J.; Teanby, N. A.; Lebonnois, S. +2 more
Aims: We study the seasonal evolution of Titan's lower stratosphere (around 15 mbar) in order to better understand the atmospheric dynamics and chemistry in this part of the atmosphere.
Methods: We analysed Cassini/CIRS far-IR observations from 2006 to 2016 in order to measure the seasonal variations of three photochemical by-products: C…
Neutral Helium Triplet Spectroscopy of Quiescent Coronal Rain with Sensitivity Estimates for Spectropolarimetric Magnetic Field Diagnostics
Schad, Thomas A.
On account of its polarizability and magnetic field sensitivity, as well as the role of neutral helium in partially ionized solar environments, the neutral helium triplet (orthohelium) system provides important, yet underutilized, diagnostics of solar coronal rain. This work describes off-limb observations of coronal rain in NOAA Active Region 124…
The Origin of High-velocity Stars from Gaia and LAMOST
Shi, Jianrong; Chen, Yuqin; Ma, Jun +4 more
Based on the second Gaia data release and spectroscopy from the Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) Data Release 5, we define the high-velocity (HiVel) stars sample as those stars with v gc > 0.85v esc, and derived the final sample of 24 HiVel stars with stellar astrometric parameters and rad…
Jets, arcs, and shocks: NGC 5195 at radio wavelengths
Muxlow, T. W. B.; Argo, M. K.; Williams, D. R. A. +10 more
We studied the nearby, interacting galaxy NGC 5195 (M 51b) in the radio, optical and X-ray bands. We mapped the extended, low-surface-brightness features of its radio-continuum emission; determined the energy content of its complex structure of shock-ionized gas; constrained the current activity level of its supermassive nuclear black hole. In par…
The origin of the LMC stellar bar: clues from the SFH of the bar and inner disc
Stetson, P. B.; Monelli, M.; Gallart, C. +2 more
We discuss the origin of the Large Magellanic Cloud (LMC) stellar bar by comparing the star formation histories (SFHs) obtained from deep colour-magnitude diagrams (CMDs) in the bar and in a number of fields in different directions within the inner disc. The CMDs, reaching the oldest main-sequence turn-offs in these very crowded fields, have been …
UV Dayglow Variability on Mars: Simulation With a Global Climate Model and Comparison With SPICAM/MEx Data
Forget, F.; Montmessin, F.; Chaufray, J. -Y. +4 more
A model able to simulate the CO Cameron bands and the CO2+ UV doublet, two of the most prominent UV emissions in the Martian dayside, has been incorporated into a Mars global climate model. The model self-consistently quantifies the effects of atmospheric variability on the simulated dayglow for the first time. Comparison of …