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Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope
Brown, R. H.; Baines, K. H.; Dougherty, M. K. +14 more
We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We…
X-ray time delays in the narrow line Seyfert 1 galaxy PG 1244+026
Done, C.; Vaughan, S.; Alston, W. N.
We analyse the X-ray time-lags in the narrow line Seyfert 1 (NLS1) galaxy PG 1244+026 (MBH ∼ 107 M⊙, L/LEdd ∼ 1). The time delay between the soft (0.3-0.7 keV) and harder (1.2-4.0 keV) variations shows the well-established switch from hard lags at low frequencies to soft lags at high frequencies. The low…
Understanding Coronal Mass Ejections and Associated Shocks in the Solar Corona by Merging Multiwavelength Observations
Pick, M.; Kerdraon, A.; Démoulin, P. +3 more
Using multiwavelength imaging observations, in EUV, white light and radio, and radio spectral data over a large frequency range, we analyzed the triggering and development of a complex eruptive event. This one includes two components, an eruptive jet and a coronal mass ejection (CME), which interact during more than 30 minutes, and can be consider…
Testing inflation and curvaton scenarios with CMB distortions
Clesse, Sébastien; Garbrecht, Björn; Zhu, Yi
Prior to recombination, Silk damping causes the dissipation of energy from acoustic waves into the monopole of the Cosmic Microwave Background (CMB), resulting in spectral distortions. These can be used to probe the primordial scalar power spectrum on smaller scales than it is possible with CMB anisotropies. An enhancement of power on these scales…
The long-term steady motion of Saturn's hexagon and the stability of its enclosed jet stream under seasonal changes
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +14 more
We investigate the long-term motion of Saturn's north pole hexagon and the structure of its associated eastward jet, using Cassini imaging science system and ground-based images from 2008 to 2014. We show that both are persistent features that have survived the long polar night, the jet profile remaining essentially unchanged. During those years, …
CoRoT 223992193: A new, low-mass, pre-main sequence eclipsing binary with evidence of a circumbinary disk
Aigrain, S.; Bouvier, J.; Lendl, M. +12 more
We present the discovery of CoRoT 223992193, a double-lined, detached eclipsing binary, comprising two pre-main sequence M dwarfs, discovered by the CoRoT space mission during a 23-day observation of the 3 Myr old NGC 2264 star-forming region. Using multi-epoch optical and near-IR follow-up spectroscopy with FLAMES on the Very Large Telescope and …
Progenitor constraints on the Type-Ia supernova SN2011fe from pre-explosion Hubble Space Telescope HeII narrow-band observations.
Maoz, D.; Graur, O.; Shara, M. M.
We present Hubble Space Telescope (HST) imaging observations of the site of the Type-Ia supernova SN2011fe in the nearby galaxy M101, obtained about 1 yr prior to the event, in a narrow band centred on the He II λ4686 Å emission line. In a `single-degenerate' progenitor scenario, the hard photon flux from an accreting white dwarf (WD), burning hyd…
Dust Formation, Evolution, and Obscuration Effects in the Very High-redshift Universe
Staguhn, Johannes; Arendt, Richard G.; Dwek, Eli +3 more
The evolution of dust at redshifts z >~ 9, and consequently the dust properties, differs greatly from that in the local universe. In contrast to the local universe, core collapse supernovae (CCSNe) are the only source of thermally condensed dust. Because of the low initial dust-to-gas mass ratio, grain destruction rates are low, so that CCSNe a…
The central parsecs of active galactic nuclei: challenges to the torus
Prieto, M. A.; Fernández-Ontiveros, J. A.; Mezcua, M. +1 more
Type 2 active galactic nuclei (AGN) are by definition nuclei in which the broad-line region and continuum light are hidden at optical/UV wavelengths by dust. Via accurate registration of infrared (IR) Very Large Telescope adaptive optics images with optical Hubble Space Telescope images we unambiguously identify the precise location of the nucleus…
Oscillations in a Sunspot with Light Bridges
Li, Bo; Huang, Zhenghua; Su, Jiangtao +4 more
The Solar Optical Telescope on board Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 2013 August 31. We analyzed a two-hour Ca II H emission intensity data set and detected strong five-minute oscillation power on both LBs and in the inner penumbra. The time-distance plot reveals that the five-minute oscillation phase does not …