Search Publications
How to deal with measurement errors and lacking data in nonlinear force-free coronal magnetic field modelling?
Inhester, B.; Wiegelmann, T.
Context. The measured solar photospheric magnetic field vector is extrapolated into the solar corona under the assumption of a force-free plasma. In the generic case this problem is nonlinear.
Aims: We aim to improve an algorithm for computing the nonlinear force-free coronal magnetic field. We are in particular interested to incorporate meas…
A Seismic Signature of a Second Dynamo?
Chaplin, William J.; Basu, Sarbani; Garcia, Rafael A. +5 more
The Sun is a variable star whose magnetic activity varies most perceptibly on a timescale of approximately 11 years. However, significant variation is also observed on much shorter timescales. We observe a quasi-biennial (2 year) signal in the natural oscillation frequencies of the Sun. The oscillation frequencies are sensitive probes of the solar…
Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause
Pickett, J. S.; Dandouras, I.; Santolík, O. +8 more
The Cluster spacecraft were favorably positioned on the nightside near the equatorial plasmapause of Earth at L ∼ 4.3 on 30 March 2002 to observe electromagnetic ion cyclotron (EMIC) rising tone emissions in association with Pc1 waves at 1.5 Hz. The EMIC rising tone emissions were found to be left-hand, circularly polarized, dispersive, and propag…
X-Ray Temperature and Mass Measurements to the Virial Radius of Abell 1413 with Suzaku
Hoshino, Akio; Sato, Kosuke; Fukazawa, Yasushi +14 more
We present X-ray observations of the northern outskirts of the relaxed galaxy cluster A 1413 with Suzaku, whose XIS instrument has the low intrinsic background needed to make measurements of these low surface brightness regions. We excised 15 point sources superimposed on the image above a flux of 1 × 10-14erg cm-2s-1
The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters
Anderson, Jay; Dotter, Aaron; Sarajedini, Ata +3 more
We present new measurements of the centers for 65 Milky Way globular clusters. Centers were determined by fitting ellipses to the density distribution within the inner 2' of the cluster center, and averaging the centers of these ellipses. The symmetry of clusters was also analyzed by comparing cumulative radial distributions on opposite sides of t…
Topography of Mars from global mapping by HRSC high-resolution digital terrain models and orthoimages: Characteristics and performance
Jaumann, R.; Oberst, J.; Preusker, F. +7 more
We report on the results of the Mars Express High-Resolution Stereo Camera (HRSC) experiment pertaining to one of its major aims, mapping the surface of Mars by high-resolution digital terrain models (DTM, up to 50 m grid spacing) and orthoimages (up to 12.5 m resolution). We introduce the specifications and characteristics of these data products …
Detection and mapping of hydrocarbon deposits on Titan
Nicholson, Philip D.; Sotin, Christophe; Barnes, Jason W. +13 more
We report the identification of compounds on Titan's surface by spatially resolved imaging spectroscopy methods through Titan's atmosphere, and set upper limits to other organic compounds. We present evidence for surface deposits of solid benzene (C6H6), solid and/or liquid ethane (C2H6), or methane (CH<…
AKARI IRC Infrared 2.5-5 µm Spectroscopy of a Large Sample of Luminous Infrared Galaxies
Nakagawa, Takao; Shirahata, Mai; Imanishi, Masatoshi +2 more
We present the results of our systematic infrared 2.5-5 µm spectroscopy of 60 luminous infrared galaxies (LIRGs) with infrared luminosities L IR = 1011-1012 L sun and 54 ultraluminous infrared galaxies (ULIRGs) with L IR >= 1012 L sun, using the AKARI Infrared Ca…
A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups
Eiroa, C.; Montesinos, B.; Montes, D. +2 more
Context. Nearby late-type stars are excellent targets for seeking young objects in stellar associations and moving groups. The origin of these structures is still misunderstood, and lists of moving group members often change with time and also from author to author. Most members of these groups have been identified by means of kinematic criteria, …
Nonlinear Propagation of Alfvén Waves Driven by Observed Photospheric Motions: Application to the Coronal Heating and Spicule Formation
Matsumoto, Takuma; Shibata, Kazunari
We have performed MHD simulations of Alfvén wave propagation along an open flux tube in the solar atmosphere. In our numerical model, Alfvén waves are generated by the photospheric granular motion. As the wave generator, we used a derived temporal spectrum of the photospheric granular motion from G-band movies of Hinode/Solar Optical Telescope. It…