Search Publications
On the ultra-compact nature of the neutron star system 1RXS J170854.4-321857: insights from X-ray spectroscopy
Armas Padilla, M.; López-Navas, E.
The relatively small family of ultra-compact X-ray binary systems is of great interest for many areas of astrophysics. We report on a detailed X-ray spectral study of the persistent neutron star low-mass X-ray binary 1RXS J170854.4-321857. We analysed two XMM-Newton observations obtained in late 2004 and early 2005 when, in agreement with previous…
Searching for correlations in Gaia DR2 unbound star trajectories
García-Bellido, J.; Barrado, D.; Montanari, F.
Scattering events with compact objects are expected in the primordial black hole (PBH) cold dark matter (CDM) scenario, due to close encounters between stars and PBHs in the dense environments of dwarf spheroidals. We develop a Bayesian framework to search for correlations among Milky Way stellar trajectories and those of globular clusters and dwa…
Analysis of the origin of water, carbon monoxide, and carbon dioxide in the Uranus atmosphere
Lampón, M.; Lara, L. M.; Rodrigo, R. +1 more
Context. We present here an analysis of the potential sources of oxygen species in the Uranus atmosphere.
Aims: Our aim is to explain the current measurements of H2O, CO, and CO2 in the Uranus atmosphere, which would allow us to constrain the influx of oxygen-bearing species and its origin in this planet.
Methods: W…
How non-stationary are moderately supercritical shocks?
Gedalin, Michael
Ion motion in a collisionless shock front is affected by macroscopic large-scale weakly varying and microscopic small-scale fast varying magnetic and electric fields. With the increase of the Mach number the role of the microscopic field is expected to become progressively more important. Using a combination of hybrid simulations and test particle…
A GALEX Far-ultraviolet Study of Dwarf Stars in Moving Groups
Smith, Graeme H.; Cochrane, Kevin M.
Far-ultraviolet (FUV) GALEX photometry of main-sequence stars in moving groups is used to verify that there is a relationship between age and FUV broadband magnitude among such stars. Samples of dwarf stars were compiled for twelve moving groups and a search made for both GALEX FUV magnitudes on the AB system and Johnson BV photometry. These data …
Magnetic flux participation in solar surface magnetism during solar cycle 24
Wang, Jing-Xiu; Jin, Chun-Lan
This study aims at investigating surface magnetic flux participation among different types of magnetic features during solar cycle 24. State-of-the-art observations from SDO/HMI and Hinode/SOT are combined to form a unique database in the interval from April 2010 to October 2015. Unlike previous studies, the statistics presented in this paper are …
Generation of photoclinometric DTMs for application to transient changes on the surface of comet 67P/Churyumov-Gerasimenko
Vincent, J. -B.; Hayes, A. G.; Tang, Y. +4 more
Context. The wide spatial and temporal coverage of 67P/Churyumov-Gerasimenko (67P) by the Rosetta mission has revealed a surface created by scattered large-scale changes and numerous small-scale changes. The many small-scale changes are of particular interest because they are unexpected and ubiquitous. As their topographic relief is often smaller …
Fragmented Comet 73P/Schwassmann-Wachmann 3
Graykowski, Ariel; Jewitt, David
Comet 73P/Schwassmann-Wachmann 3 has been observed to fragment on several occasions, yet the cause of its fragmentation remains poorly understood. We use previously unpublished archival Hubble Space Telescope data taken in 2006 to study the properties of the primary fragment, 73P-C, in order to constrain the potential fragmentation mechanisms. Cur…
Chemical composition of the outer halo globular cluster Palomar 15
Rich, R. Michael; Xu, Siyi; Koch, Andreas
Globular clusters (GCs) in the outer Milky Way halo are important tracers of the assembly history of our Galaxy. Only a few of these objects show spreads in heavier elements beyond the canonical light-element variations that have essentially been found throughout the entire Galactic GC system, suggesting a more complex origin and evolution of thes…
CN Andromedae: a shallow contact binary with a possible tertiary component
Soydugan, Faruk; Aliçavuş, Fahri; Yildirim, Muhammed Faruk
In this study, new photometric observations of shallow contact binary CN Andromedae (CN And) were performed and multi-color (BV R) CCD light curves (LCs) were obtained. Simultaneous analysis of new LCs and published radial velocity (RV) data reveals that the system is an early contact binary in which both components have recently filled their inne…