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Are Solar Active Regions with Major Flares More Fractal, Multifractal, or Turbulent Than Others?
Georgoulis, Manolis K.
Multiple recent investigations of solar magnetic-field measurements have raised claims that the scale-free (fractal) or multiscale (multifractal) parameters inferred from the studied magnetograms may help assess the eruptive potential of solar active regions, or may even help predict major flaring activity stemming from these regions. We investiga…
Carbon-rich Dust Production in Metal-poor Galaxies in the Local Group
van Loon, J. Th.; Wood, P. R.; Zijlstra, A. A. +7 more
We have observed a sample of 19 carbon stars in the Sculptor, Carina, Fornax, and Leo I dwarf spheroidal galaxies with the Infrared Spectrograph on the Spitzer Space Telescope. The spectra show significant quantities of dust around the carbon stars in Sculptor, Fornax, and Leo I, but little in Carina. Previous comparisons of carbon stars with simi…
Spatial variation of the cooling lines in the Orion Bar from Herschel/PACS
Abergel, A.; Bernard, J. -P.; White, G. J. +8 more
Context. The energetics in photo-dissociation regions (PDRs) are mainly regulated by the balance between the heating from the photo-electric effect acting on dust grains, and the cooling via the copious emission of photons in far-infrared lines. The Orion Bar is a luminous and nearby PDR, which presents to the observer an ideal edge-on orientation…
The dust and gas properties of M83
Clements, D. L.; Boquien, M.; Roussel, H. +17 more
We examine the dust and gas properties of the nearby, barred galaxy M83, which is part of the Very Nearby Galaxy Survey. Using images from the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging REceiver (SPIRE) instruments of Herschel, we examine the dust temperature and dust mass surface density distribution. …
Thermal Properties of a Solar Coronal Cavity Observed with the X-Ray Telescope on Hinode
Reeves, Katharine K.; Gibson, Sarah E.; Kucera, Therese A. +2 more
Coronal cavities are voids in coronal emission often observed above high latitude filament channels. Sometimes, these cavities have areas of bright X-ray emission in their centers. In this study, we use data from the X-ray Telescope (XRT) on the Hinode satellite to examine the thermal emission properties of a cavity observed during 2008 July that …
Constraints on the history of open-basin lakes on Mars from the composition and timing of volcanic resurfacing
Mustard, John F.; Goudge, Timothy A.; Head, James W. +1 more
Abundant evidence exists for valley network-related fluvial activity near the Noachian-Hesperian transition on Mars, and areally significant quantities of volcanic ridged plains were emplaced during this period as well. Thus, it is worthwhile to explore the hypothesis that lava-water interaction occurred on the surface of Mars at this time. We ana…
BR1202-0725: an extreme multiple merger at z = 4.7
Omont, A.; Gavazzi, R.; Salomé, P. +5 more
The radio-quiet quasar BR1202-0725 (z = 4.695) is a remarkable source with a bright northwest (NW) companion detected at submillimeter and radio wavelengths but invisible in the optical. In the absence of amplification by gravitational lensing, BR1202-0725 would be the most luminous binary CO and far-infrared (far-IR) source in the Universe. In th…
SN 2010ay is a Luminous and Broad-lined Type Ic Supernova within a Low-metallicity Host Galaxy
Price, P. A.; Berger, E.; Cline, T. +38 more
We report on our serendipitous pre-discovery detection and follow-up observations of the broad-lined Type Ic supernova (SN Ic) 2010ay at z = 0.067 imaged by the Pan-STARRS1 3π survey just ~4 days after explosion. The supernova (SN) had a peak luminosity, MR ≈ -20.2 mag, significantly more luminous than known GRB-SNe and one of the most …
Numerical Simulations of the Magnetic Rayleigh-Taylor Instability in the Kippenhahn-Schlüter Prominence Model. II. Reconnection-triggered Downflows
Shibata, Kazunari; Isobe, Hiroaki; Hillier, Andrew +1 more
The launch of the Hinode satellite has allowed high-resolution observations of supersonic bright downflows in quiescent prominences, known as prominence knots. We present observations in the Ca II H spectral line using the Solar Optical Telescope on board the Hinode satellite of a descending plasma knot of size ~900 km. The knot initially undergoe…
A clear view of the multifaceted dayside ionosphere of Mars
Tellmann, Silvia; Pätzold, Martin; Häusler, Bernd +10 more
By examining electron density profiles from the Mars Express Radio Science Experiment MaRS, we show that the vertical structure of the dayside ionosphere of Mars is more variable and more complex than previously thought. The top of the ionosphere can be below 250 km (25% occurrence rate) or above 650 km (1%); the topside ionosphere can be well-des…