Search Publications
Magnetic Energy Dissipation during the 2014 March 29 Solar Flare
Aschwanden, Markus J.
We calculated the time evolution of the free magnetic energy during the 2014 March 29 flare (SOL2014 March 29T17:48), the first X-class flare detected by the Interface Region Imaging Spectrograph (IRIS). The free energy was calculated from the difference between the nonpotential field, constrained by the geometry of observed loop structures, and t…
Lower atmosphere minor gas abundances as retrieved from Venus Express VIRTIS-M-IR data at 2.3 µm
Haus, Rainer; Kappel, David; Arnold, Gabriele
Minor gas abundances in the lower atmosphere of Venus' southern hemisphere are investigated using spectroscopic nightside measurements recorded by the Visible and InfraRed Thermal Imaging Spectrometer aboard ESA's Venus Express mission in the moderate spectral resolution infrared mapping channel (VIRTIS-M-IR, 1-5 µm, FWHM=17 nm). The entire …
Interchange Reconnection Forced by the Filament Eruption Inside a Pseudo-streamer
Yang, Jiayan; Bi, Yi; Hong, Junchao +2 more
We present rare observational signatures of interchange reconnection (IR) forced by the filament eruption inside a pseudo-streamer (PS). The PS was centered above a positive-polarity region bounded by two negative-polarity coronal holes (CHs), and thus its base contained two polarity inversion lines and a pair of loop arcades where two filaments w…
IFU spectroscopy of 10 early-type galactic nuclei - III. Properties of the circumnuclear gas emission
Ricci, T. V.; Steiner, J. E.; Menezes, R. B.
Many early-type galaxies have ionized gas emission in their centres that extends to scales of ∼1 kpc. The majority of such objects are classified as low-ionization nuclear emission regions (LINERs), but the nature of their ionizing source is still not clear. The kinematics associated with these gaseous structures usually shows deviations from a pu…
New insights into the evolution of the FR I radio galaxy 3C 270 (NGC 4261) from VLA and GMRT radio observations
Raychaudhury, Somak; Giacintucci, Simona; Ishwara-Chandra, C. H. +4 more
We present the Giant Metrewave Radio Telescope 240 MHz observations of the nearby luminous Fanaroff-Riley type I radio source 3C 270, in the group-central elliptical NGC 4261. Combining these data with reprocessed Very Large Array 1.55 and 4.8 GHz observations, we produce spectral-index maps that reveal a constant spectral index along the jets and…
The Transient Accreting X-Ray Pulsar XTE J1946+274: Stability of X-Ray Properties at Low Flux and Updated Orbital Solution
Enoto, Teruaki; Terada, Yukikatsu; Hemphill, Paul B. +19 more
We present a timing and spectral analysis of the X-ray pulsar XTE J1946+274 observed with Suzaku during an outburst decline in 2010 October and compare with previous results. XTE J1946+274 is a transient X-ray binary consisting of a Be-type star and a neutron star with a 15.75 s pulse period in a 172 days orbit with 2-3 outbursts per orbit during …
Anatomy of the AGN in NGC 5548. V. A clear view of the X-ray narrow emission lines
Kaastra, J. S.; Kriss, G. A.; Bianchi, S. +15 more
Context. Our consortium performed an extensive multi-wavelength campaign of the nearby Seyfert 1 galaxy NGC 5548 in 2013-14. The source appeared unusually heavily absorbed in the soft X-rays, and signatures of outflowing absorption were also present in the UV. He-like triplets of neon, oxygen and nitrogen, and radiative recombination continuum (RR…
Measuring an Eruptive Prominence at Large Distances from the Sun. I. Ionization and Early Evolution
Howard, T. A.
Measurements of Hα emission within an eruptive solar prominence are presented, using white light polarization properties as a proxy for the presence of Hα in the STEREO COR1 and COR2 coronagraphs. The transition from Hα emission to Thomson scattering radiance serves as an indicator of the ionization of the prominence, and I discuss the physical im…
Young open clusters in the Galactic star forming region NGC 6357
Marconi, G.; Giannetti, A.; Beltrán, M. T. +3 more
Context. NGC 6357 is an active star forming region with very young massive open clusters. These clusters contain some of the most massive stars in the Galaxy and strongly interact with nearby giant molecular clouds.
Aims: We study the young stellar populations of the region and of the open cluster Pismis 24, focusing on their relationship wit…
Impact craters: An ice study on Rhea
White, Oliver L.; Cruikshank, Dale P.; Dalle Ore, Cristina M. +2 more
The goal of this project is to study the properties of H2O ice in the environment of the Saturn satellites and in particular to measure the relative amounts of crystalline and amorphous H2O ice in and around two craters on Rhea. The craters are remnants of cataclysmic events that, by raising the local temperature, melted the …