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Properties of high-degree oscillation modes of the Sun observed with Hinode/SOT
Kosovichev, A. G.; Mitra-Kraev, U.; Sekii, T.
Aims:With the Solar Optical Telescope on Hinode, we investigate the basic properties of high-degree solar oscillations observed at two levels in the solar atmosphere, in the G-band (formed in the photosphere) and in the Ca II H line (chromospheric emission).
Methods: We analyzed the data by calculating the individual power spectra as well as t…
A Kiloparsec-Scale X-Ray Jet in the BL Lac Source S5 2007+777
Maraschi, L.; Cheung, C. C.; Tavecchio, F. +2 more
X-ray jets in AGNs are commonly observed in FR II and FR I radio galaxies, but rarely in BL Lac objects, most probably due to their orientation close to the line of sight and the ensuing foreshortening effects. Only three BL Lac objects are known so far to contain a kpc-scale X-ray jet. In this paper we present the evidence for the existence of a …
High-resolution spectroscopy of K-shell praseodymium with a high-energy microcalorimeter
Boyce, K. R.; Kilbourne, C. A.; Porter, F. S. +7 more
We present a measurement of the K-shell spectrum of He-like through Be-like praseodymium ions trapped in the Livermore SuperEBIT electron beam ion trap using a bismuth absorber pixel on the XRS/EBIT microcalorimeter. This measurement is the first of its kind where the n=2 to n=1 transitions of the various charge states are spectroscopically resolv…
Obscured and powerful AGN and starburst activities at z ~ 3.5
Berta, S.; Omont, A.; Stalin, C. S. +9 more
Aims: Short phases of coeval powerful starburst and AGN activity during the lifetimes of the most massive galaxies are predicted by various models of galaxy formation and evolution. In spite of their recurrence and high luminosity, such events are rarely observed. Finding such systems, understanding their nature, and constraining their number dens…
Probing a massive radio galaxy with gravitational lensing
Muxlow, T. W. B.; McKean, J. P.; Koopmans, L. V. E. +3 more
The gravitational lens system CLASS B2108+213 has two lensed images separated by 4.56arcsec. Such a wide image separation suggests that the lens is either a massive galaxy or composed of a group of galaxies. To investigate the structure of the lensing potential we have carried out new high-resolution imaging of the two lensed images at 1.7GHz with…
Automated Prediction of CMEs Using Machine Learning of CME - Flare Associations
Ipson, S.; Colak, T.; Qahwaji, R. +1 more
Machine-learning algorithms are applied to explore the relation between significant flares and their associated CMEs. The NGDC flares catalogue and the SOHO/LASCO CME catalogue are processed to associate X and M-class flares with CMEs based on timing information. Automated systems are created to process and associate years of flare and CME data, w…
Intermittent turbulence, noisy fluctuations, and wavy structures in the Venusian magnetosheath and wake
Zhang, T. L.; Baumjohann, W.; Volwerk, M. +3 more
Recent research has shown that distinct physical regions in the Venusian induced magnetosphere are recognizable from the variations of strength of the magnetic field and its wave/fluctuation activity. In this paper the statistical properties of magnetic fluctuations are investigated in the Venusian magnetosheath and wake regions. The main goal is …
The statistics of foreshock cavities: results of a Cluster survey
Schwartz, S. J.; Sibeck, D. G.; Billingham, L.
We use Cluster magnetic field, thermal ion, and energetic particle observations upstream of the Earth's bow shock to investigate the occurrence patterns of foreshock cavities. Such cavities are thought to form when bundles of magnetic field connect to the quasi-parallel bow shock. Shock-processed suprathermal ions can then stream along the field, …
Removal of Titan's noble gases by their trapping in its haze
Bar-Nun, Akiva; Jacovi, Ronen
Titan's haze, formed by photolysis of C 2H 2, C 2H 4 and HCN, was found experimentally to trap Ar, Kr and Xe with efficiencies of 3.5 × 10 -4, 1.9 × 10 -3 and 6.5 × 10 -2 [noble gas atom]/[carbon atom] in the polymer, respectively. The rate of aerosol formation and settli…
Integral field spectroscopy of four lensed quasars: analysis of their neighborhood and evidence for microlensing
Kneib, J. -P.; Faure, C.; Alloin, D. +4 more
Context: Gravitationally lensed quasars constitute an independent tool to derive the Hubble constant through the time-delays of their different images; they offer as well the opportunity to study the mass distribution and interstellar medium of their lensing galaxies and, through microlensing due to stars in their lensing galaxy, they also allow o…