Search Publications
Comparative analysis of Venus and Mars magnetotails
Coates, A. J.; Kallio, E.; Fedorov, A. +47 more
We have an unique opportunity to compare the magnetospheres of two non-magnetic planets as Mars and Venus with identical instrument sets Aspera-3 and Aspera-4 on board of the Mars Express and Venus Express missions. We have performed both statistical and case studies of properties of the magnetosheath ion flows and the flows of planetary ions behi…
Hinode's Observational Result on the Saturation of Magnetic Helicity Injected into the Solar Atmosphere and Its Relation to the Occurrence of a Solar Flare
Magara, Tetsuya; Tsuneta, Saku
This paper is intended to present key features of the evolution toward the onset of a solar flare, using Hinode's observations on the photospheric magnetic field. Hinode can provide the temporal development of the photospheric field as a vector quantity, which shows that magnetic shear is initially developed in a flare-productive active region (AR…
The early-type galaxies NGC 1407 and NGC 1400 - II. Star formation and chemical evolutionary history
Forbes, Duncan A.; Proctor, Robert N.; Brough, Sarah +2 more
We present a possible star formation and chemical evolutionary history for two early-type galaxies NGC 1407 and NGC 1400. They are the two brightest galaxies of the NGC 1407 (or Eridanus-A) group, one of the 60 groups studied as part of the Group Evolution Multi-wavelength Study.
Our analysis is based on new high signal-to-noise ratio spatial…Young star clusters in interacting galaxies - NGC 1487 and NGC 4038/4039
Lehnert, M. D.; Vacca, W. D.; Chandar, R. +3 more
We estimate the dynamical masses of several young (≈10 Myr) massive star clusters in two interacting galaxies, NGC 4038/4039 (“The Antennae”) and NGC 1487, under the assumption of virial equilibrium. These are compared with photometric mass estimates from K-band photometry assuming a standard Kroupa IMF. The clusters were selected to have near-inf…
Density structure of an active region and associated moss using Hinode/EIS
Young, P. R.; Mason, H. E.; Del Zanna, G. +1 more
Context: Studying the problem of active region heating requires precise measurements of physical plasma parameters such as electron density, temperature, etc. It is also important to understand the relationship of coronal structures with the magnetic field. The Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode provides a rare opportunit…
Jupiter's changing auroral location
Grodent, Denis; GéRard, Jean-Claude; Saglam, Adem +2 more
We examine the case of significant latitudinal shifts of the Jovian northern auroral emissions appearing in a data set spanning nine years of observations with the Hubble Space Telescope in the far ultraviolet. The extended data set makes it possible to compare the location of the main auroral emission with similar viewing geometries and satellite…
Magnetic double gradient mechanism for flapping oscillations of a current sheet
Semenov, V. S.; Erkaev, N. V.; Biernat, H. K.
A new kind of magnetohydrodynamic waves are analyzed for a current sheet in a presence of a small normal magnetic field component varying along the sheet. As a background, two simplified models of a current sheet are considered with a uniform and nonuniform current distributions in the current sheet. On a basis of these two models, the flapping-ty…
Tracing jet-ISM interaction in young AGN: correlations between [O III] λ 5007 Å and 5-GHz emission
Labiano, A.
Aims: I study the interaction between young AGN and their host galaxies based on their ionized gas and radio emission, and analyze possible implications for radio galaxy evolution.
Methods: The [O III] λ 5007 Å line and 5-GHz radio properties are compared and studied for a large, representative sample of GPS and CSS (i.e., young) quasars and r…
The Long-Term Variability of the X-Ray Sources in NGC 6946 and NGC 4485/4490
Kong, Albert K. H.; Homan, Jeroen; Fridriksson, Joel K. +2 more
We analyze data from five Chandra observations of the spiral galaxy NGC 6946 and from three Chandra observations of the irregular/spiral interacting galaxy pair NGC 4485/4490, with an emphasis on investigating the long-term variability exhibited by the source populations. We detect 90 point sources coincident with NGC 6946 down to luminosities of …
Geology of Shackleton Crater and the south pole of the Moon
Josset, Jean-Luc; Spudis, Paul D.; Bussey, Ben +2 more
Using new SMART-1 AMIE images and Arecibo and Goldstone high resolution radar images of the Moon, we investigate the geological relations of the south pole, including the 20 km-diameter crater Shackleton. The south pole is located inside the topographic rim of the South Pole-Aitken (SPA) basin, the largest and oldest impact crater on the Moon and …