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The potential for prebiotic chemistry in the possible cryovolcanic dome Ganesa Macula on Titan
Lorenz, R. D.; Neish, C. D.; O'Brien, D. P. +1 more
New observations of Titan by the Cassini spacecraft suggest the presence of cryovolcanism on the surface. Cryovolcanism has important astrobiological implications, as it provides a means of exposing Titan's organics to liquid water, transforming hydrocarbons and nitriles into more evolved and oxidized prebiotic species. One possible cryovolcano - …
Simulations of thermally broadened H I Ly α absorption arising in the warm-hot intergalactic medium
Richter, P.; Fang, T.; Bryan, G. L.
Recent far-ultraviolet (FUV) absorption line measurements of low-redshift quasars have unveiled a population of intervening broad H i Ly α absorbers (BLAs) with large Doppler parameters (b≥ 40 km s-1). If the large width of these lines is dominated by thermal line broadening, the BLAs may trace highly-ionized gas in the warm-hot interga…
A Time-dependent Leptonic Model for Microquasar Jets: Application to LS I +61 303
Gupta, S.; Böttcher, M.
The Galactic high-mass X-ray binary and jet source (microquasar) LS I +61 303 has recently been detected at TeV γ-ray energies by the MAGIC telescope. We have applied a time-dependent leptonic jet model to the broadband spectral energy distribution (SED), and we have suggested (although not unambiguously detected) an orbital modulation of the very…
Ultraviolet-bright, High-Redshift Ultraluminous Infrared Galaxies
Woodgate, Bruce; Teplitz, Harry; Williger, Gerard M. +3 more
We present Spitzer Space Telescope observations of the z=2.38 Lyα emitter overdensity associated with galaxy cluster J2143-4423, the largest known structure (110 Mpc) above z=2. We imaged 22 of the 37 known Lyα emitters within the filament-like structure, using the MIPS 24 µm band. We detected six of the Lyα emitters, including three of the …
The Latitudinal Excursion of Coronal Magnetic Field Lines in Response to Differential Rotation: MHD Simulations
Riley, Pete; Linker, Jon A.; Mikić, Zoran +1 more
Solar energetic particles, which are believed to originate from corotating interacting regions (CIRs) at low heliographic latitude, were observed by the Ulysses spacecraft even as it passed over the Sun's poles. One interpretation of this result is that high-latitude field lines intercepted by Ulysses connect to low-latitude CIRs at much larger he…
Solar Convection Zone Dynamics: How Sensitive Are Inversions to Subtle Dynamo Features?
Thompson, M. J.; Howe, R.; Komm, R. +5 more
The nearly 10 year span of medium-degree helioseismic data from the Global Oscillation Network Group and the Michelson Doppler Imager has allowed us to study the evolving flows in the solar convection zone over most of solar cycle 23. Using two independent two-dimensional rotation inversion techniques and extensive studies of the resolution using …
Light Curves of 20-100 km Kuiper Belt Objects Using the Hubble Space Telescope
Bernstein, Gary M.; Trilling, David E.
We report high-precision photometry of three small and one larger Kuiper Belt objects (KBOs) obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope. The three small bodies are the smallest KBOs for which light-curve measurements are available. The object 2003 BF91 has a diameter of 20 km (assuming 10% albedo) …
Three-dimensional finite difference time domain modeling of the Schumann resonance parameters on Titan, Venus, and Mars
Yang, Heng; Pasko, Victor P.; Yair, Yoav
The conducting ionosphere and conducting surface of Titan, Venus, and Mars form a concentric resonator, which would support the possibility of the existence of global electromagnetic resonances. On Earth, such resonances are commonly referred to as Schumann resonances and are excited by lightning discharges. The detection of such resonances on oth…
Disentangling the synchrotron and inverse Compton variability in the X-ray emission of the intermediate BL Lacertae object S5 0716+71
Emmanoulopoulos, D.; Wagner, S. J.; Ferrero, E. +1 more
Context: .The possibility to detect simultaneously in the X-ray band the synchrotron and Inverse Compton (IC) emission of intermediate BL Lac objects offers the unique opportunity to study contemporaneously the low- and high-energy tails of the electron distribution in the jets of these sources.
Aims: .We attempted to disentangle the X-ray spe…
The Rate of Emergence of Magnetic Dipoles in Coronal Holes and Adjacent Quiet-Sun Regions
Abramenko, V. I.; Yurchyshyn, V. B.; Fisk, L. A.
Observations from the Michelson Doppler Imager and the EUV Imaging Telescope on the Solar and Heliospheric Observatory are analyzed to determine the rate of emergence of new magnetic flux in coronal holes and in surrounding regions on the quiet Sun. Coronal holes are regions where the open magnetic flux of the Sun, the component that forms the hel…