Search Publications
Subsurface Sediment Mobilization in the Southern Chryse Planitia on Mars
Hauber, E.; Michael, G.; Brož, P. +2 more
The southern part of the smooth plain of Chryse Planitia on Mars hosts a large population of kilometer-sized (from 0.2 to 20 km) landforms spread over a wide area. Based on the investigation of a small part of this area, Komatsu et al. (2016, https://doi.org/10.1016/j.icarus.2015.12.032) p…
Discovery of an X-Ray Quasar Wind Driving the Cold Gas Outflow in the Ultraluminous Infrared Galaxy IRAS F05189-2524
Veilleux, Sylvain; Tombesi, Francesco; Lohfink, Anne M. +2 more
We present new XMM-Newton and NuSTAR observations of the galaxy merger IRAS F05189-2524, which is classified as an ultraluminous infrared galaxy and optical Seyfert 2 at z = 0.0426. We test a variety of spectral models that yield a best fit consisting of an absorbed power law with emission and absorption features in the Fe K band. Remarkably, we f…
Statistical detection of a tidal stream associated with the globular cluster M68 using Gaia data
Miralda-Escudé, Jordi; Palau, Carles G.
A method to search for tidal streams and to fit their orbits based on maximum likelihood is presented and applied to the Gaia data. Tests of the method are performed showing how a simulated stream produced by tidal stripping of a star cluster is recovered when added to a simulation of the Gaia catalogue. The method can be applied to search for str…
Modeling Mg II During Solar Flares. I. Partial Frequency Redistribution, Opacity, and Coronal Irradiation
Kerr, Graham S.; Carlsson, Mats; Allred, Joel C.
The Interface Region Imaging Spectrograph has routinely observed the flaring Mg II near-ultraviolet (NUV) spectrum, offering excellent diagnostic potential and a window into the location of energy deposition. A number of studies have forward-modeled both the general properties of these lines and specific flare observations. Generally these have fo…
Characteristics of the Two Sequences Seen in the High-velocity Hertzsprung-Russell Diagram in Gaia DR2
Casagrande, Luca; Feltzing, Sofia; Sahlholdt, Christian L.
In this study we use a sample of about 9 million SkyMapper stars with metallicities to investigate the properties of the two stellar populations seen in the high-velocity (V T > 200 km s-1) Gaia DR2 Hertzsprung-Russell diagram. Based on 10,000 red giant branch (RGB) stars (out of 75,000 with high velocity), we find that th…
The W-subtype active contact binary PZ UMa with a possible more massive tertiary component
Soonthornthum, Boonrucksar; Zhou, Xiao
Two sets of multiple-color (B, V, RC, IC) light curves of PZ UMa were observed independently with the 2.4 m telescope at the Thai National Observatory and the 1 m telescope at Yunnan Observatories. The light curves were analyzed with the Wilson-Devinney program and the two sets of light curves produced consistent results, whi…
Observations of the chemical and thermal response of 'ring rain' on Saturn's ionosphere
Baines, Kevin H.; O'Donoghue, James; Moore, Luke +4 more
In this study we performed a new analysis of ground-based observations that were taken on 17 April 2011 using the 10-metre Keck telescope on Mauna Kea, Hawaii. Emissions from H3+, a major ion in Saturn's ionosphere, were previously analyzed from these observations, indicating that peaks in emission at specific latitudes were …
A Comparative Study of 2017 July and 2012 July Complex Eruptions: Are Solar Superstorms “Perfect Storms” in Nature?
Vourlidas, Angelos; Liu, Ying D.; Hu, Huidong +2 more
It is paramount from both scientific and societal perspectives to understand the generation of extreme space weather. We discuss the formation of solar superstorms based on a comparative study of the 2012 July 23 and 2017 July 23 eruptions. The first one is Carrington-class, and the second could rival the 1989 March event that caused the most inte…
XMMSL2 J144605.0+685735: a slow tidal disruption event
Read, A. M.; Berger, E.; Komossa, S. +6 more
Aims: We investigate the evolution of X-ray selected tidal disruption events.
Methods: New events are found in near real-time data from XMM-Newton slews, and are monitored by multi-wavelength facilities.
Results: In August 2016, X-ray emission was detected from the galaxy XMMSL2 J144605.0+685735 (also known as 2MASX 14460522+6857311…
Are Slope Streaks Indicative of Global-Scale Aqueous Processes on Contemporary Mars?
Zorzano, María-Paz; Bhardwaj, Anshuman; Sam, Lydia +1 more
Slope streaks are prevalent and intriguing dark albedo surface features on contemporary Mars. Slope streaks are readily observed in the equatorial and subequatorial dusty regolith regions with low thermal inertia. They gradually fade over decadal timescales. The proposed mechanisms for their formation vary widely based on several physicochemical a…