Search Publications
Possible role of brines in the darkening and flow-like features on the Martian polar dunes based on HiRISE images
Möhlmann, D.; Kereszturi, A.; Berczi, Sz. +3 more
This work identifies and describes features of the changing seasonal frost-covered surface of Mars based on HiRISE images, and analyses the possibility that ephemeral liquid brine formation produces them. Because some of these dark features show flow-like appearance, and salts on Mars are present, liquid brines might be also present, possibly acco…
HST and VLT observations of the neutron star 1E 1207.4-5209
Caraveo, P. A.; Bignami, G. F.; de Luca, A. +4 more
The peculiar central compact object 1E 1207.4-5209 in the G296.5+10.0 supernova remnant has been proposed to be an “anti-magnetar” - a young neutron star born with a weak dipole field. Accretion, possibly of supernova fallback material, has also been invoked to explain a large surface temperature anisotropy as well as the generation of peculiar cy…
The deeply obscured AGN of NGC 4945. I. Spitzer-IRS maps of [Ne V], [Ne II], H2 0-0 S(1), S(2), and other tracers
Smith, J. D.; Spaans, M.; Spoon, H. W. W. +1 more
Context. The nearly edge-on galaxy NGC 4945 is one of the closest galaxies where an AGN and starburst coexist, and is one of the brightest sources at 100 keV. Near and mid-infrared spectroscopy have shown very strong obscuration of its central region, rivaled only in strength by some of the most deeply obscured ULIRGs.
Aims: We determine the …
The metal contents of two groups of galaxies
Kaastra, J. S.; de Plaa, J.; de Vries, C. P. +4 more
Context. The hot gas in clusters and groups of galaxies is continuously being enriched with metals from supernovae and stars. It is well established that the enrichment of the gas with elements from oxygen to iron is mainly caused by supernova explosions. The origins of nitrogen and carbon are still being debated. Possible candidates include massi…
Characterization and Improvement of the Image Quality of the Data Taken with the Infrared Camera (IRC) Mid-Infrared Channels on Board AKARI
Oyabu, Shinki; Onaka, Takashi; Tanabé, Toshihiko +7 more
Mid-infrared images frequently suffer artifacts and extended point-spread functions (PSFs). We investigate the characteristics of the artifacts and the PSFs in images obtained with the infrared camera (IRC) on board AKARI at four mid-infrared bands of the S7 (7 µm), S11 (11 µm), L15 (15 µm), and L24 (24 µm). Removal of the …
Comparison of Nonlinear Force-Free Field and Potential Field in the Quiet Sun
Zhang, H. Q.; Su, J. T.; Liu, S.
In this paper, a potential field extrapolation and three nonlinear force-free (NLFF) field extrapolations (optimization, direct boundary integral (DBIE), and approximate vertical integration (AVI) methods) are used to study the spatial configuration of magnetic field in the quiet Sun. It is found that differences in the computed field strengths am…
Near-IR search for lensed supernovae behind galaxy clusters. III. Implications for cluster modeling and cosmology
Amanullah, R.; Goobar, A.; Mörtsell, E. +6 more
Context. Massive galaxy clusters at intermediate redshifts act as gravitational lenses that can magnify supernovae (SNe) occurring in background galaxies.
Aims: We assess the possibility of using lensed SNe to constraint the mass models of galaxy clusters and the Hubble parameter at high redshift.
Methods: Owing to the standard candle na…
Constraining Saturn's Core Properties by a Measurement of Its Moment of Inertia—Implications to the Cassini Solstice Mission
Helled, R.
Knowledge of Saturn's axial moment of inertia can provide valuable information on its internal structure. We suggest that Saturn's angular momentum may be determined by the Solstice Mission (Cassini XXM) by measuring Saturn's pole precession rate and the Lense-Thirring acceleration on the spacecraft, and therefore put constraints on Saturn's momen…
A Dwarf Nova in the Globular Cluster M13
Knigge, C.; van den Berg, M.; Servillat, M. +4 more
Dwarf novae (DNe) in globular clusters (GCs) seem to be rare with only 13 detections in the 157 known Galactic GCs. We report the identification of a new DN in M13, the 14th DN identified in a GC to date. Using the 2 m Faulkes Telescope North, we conducted a search for stars in M13 that show variability over a year (2005-2006) on timescales of day…
Emergence of polar-jet polygons from jet instabilities in a Saturn model
Ingersoll, Andrew P.; Dowling, Timothy E.; Sayanagi, Kunio M. +1 more
Voyager flybys of Saturn in 1980-1981 revealed a circumpolar wave at ≈78° north planetographic latitude. The feature had a dominant wavenumber 6 mode, and has been termed the Hexagon from its geometric appearance in polar-projected mosaics. It was also noted for being stationary with respect to Saturn's Kilometric Radiation (SKR) rotation rate. Th…