Search Publications
HD 83443c: A Highly Eccentric Giant Planet on a 22 yr Orbit
Kane, Stephen R.; Butler, R. P.; Wittenmyer, Robert A. +20 more
We report the discovery of a highly eccentric long-period Jovian planet orbiting the hot-Jupiter host HD 83443. By combining radial velocity data from four instruments (AAT/UCLES, Keck/HIRES, HARPS, Minerva-Australis) spanning more than two decades, we find evidence for a planet with m sin $i={1.35}_{-0.06}^{+0.07}$ M J, moving on an or…
Investigating the most promising Yarkovsky candidates using Gaia DR2 astrometry
Oszkiewicz, Dagmara; Bartczak, Przemysław; Dziadura, Karolina
The Yarkovsky drift is a major factor driving the orbital evolution of asteroids. To date, the effect has been detected for a few hundred asteroids, mainly near-Earth objects. Before the start of the European Space Agency Gaia mission, the expectation was to recognize many other asteroids manifesting the Yarkovsky drift through the high precision …
Variations of the Plasma Environment Revealed by the Evolution of the Supra-arcade Fan in the 2017 September 10 Flare
Cai, Qiangwei; Ye, Jing; Feng, Hengqiang +1 more
Based on observations from the Interface Region Imaging Spectrograph and Hinode, we analyze the thermodynamic evolution of the supra-arcade fan (SAF) in the 2017 September 10 flare. The SAF presents discontinuous characters during the rising process, indicating a nonuniform process of magnetic reconnection in the solar eruption. The intensity peak…
Masses, bulk densities, and macroporosities of asteroids (15) Eunomia, (29) Amphitrite, (52) Europa, and (445) Edna based on Gaia astrometry
Granvik, M.; Siltala, L.
Context. Gaia Data Release 2 (DR2) includes milliarcsecond-accuracy astrometry for 14 099 asteroids. One of the main expected scientific applications of these data is asteroid mass estimation via the modeling of perturbations during asteroid-asteroid encounters.
Aims: We explore the practical impact of the Gaia astrometry of asteroids for the…
Martian CO2 Ice Observation at High Spectral Resolution With ExoMars/TGO NOMAD
Vandaele, A. C.; Daerden, F.; Thomas, I. R. +14 more
The Nadir and Occultation for MArs Discovery (NOMAD) instrument suite aboard ExoMars/Trace Gas Orbiter spacecraft is mainly conceived for the study of minor atmospheric species, but it also offers the opportunity to investigate surface composition and aerosols properties. We investigate the information content of the Limb, Nadir, and Occultation (…
A WHIM origin for the soft excess emission in the Coma cluster
Bonamente, Massimiliano; Lieu, Richard; Mirakhor, Mohammad +1 more
This paper provides a new analysis of ROSAT observations of the Coma cluster, to determine the amount of soft X-ray radiation in excess of the contribution from the hot intracluster medium (ICM). The re-analysis is made possible by a high-resolution study of the hot ICM with the XMM-Newton and Planck telescopes out to the cluster's virial radius. …
Accurate Modeling of Lyα Profiles and Their Impact on Photolysis of Terrestrial Planet Atmospheres
Loyd, R. O. Parke; Peacock, Sarah; Schwieterman, Edward W. +4 more
Accurately measuring and modeling the Lyα (Lyα; λ1215.67 Å) emission line from low-mass stars is vital for our ability to build predictive high energy stellar spectra, yet interstellar medium (ISM) absorption of this line typically prevents model-measurement comparisons. Lyα also controls the photodissociation of important molecules, like water an…
A Near-infrared Look at AGN Feedback in Bulgeless Galaxies
Bohn, Thomas; Canalizo, Gabriela; Satyapal, Shobita +1 more
While it is generally believed that supermassive black holes (SMBHs) lie in most galaxies with bulges, few SMBHs have been confirmed in bulgeless galaxies. Identifying such a population could provide important insights to the BH seed population and secular BH growth. To this end, we obtained near-infrared (NIR) spectroscopic observations of a samp…
Linking high- and low-mass star formation. Observation-based continuum modelling and physical conditions
Kristensen, L. E.; Jørgensen, J. K.; Pitts, R. L. +1 more
Context. Astronomers have yet to establish whether high-mass protostars form from high-mass prestellar cores, similar to their lower-mass counterparts, or from lower-mass fragments at the heart of a pre-protostellar cluster undergoing large-scale collapse. Part of the uncertainty is due to a shortage of envelope structure data on protostars of a f…
Changes in the Na D1 Absorption Components of η Carinae Provide Clues on the Location of the Dissipating Central Occulter
Moffat, Anthony F. J.; Hillier, D. John; Gull, Theodore R. +9 more
The Na D absorption doublet in the spectrum of η Carinae is complex, with multiple absorption features associated with the Great Eruption (1840s), the Lesser Eruption (1890s), and the interstellar clouds. The velocity profile is further complicated by the P Cygni profile originating in the system's stellar winds and blending with the He I λ5876 pr…