Search Publications
Electrostatic solitary waves in current layers: from Cluster observations during a super-substorm to beam experiments at the LAPD
Gurnett, D. A.; Lakhina, G. S.; Tsurutani, B. T. +15 more
Electrostatic Solitary Waves (ESWs) have been observed by several spacecraft in the current layers of Earth's magnetosphere since 1982. ESWs are manifested as isolated pulses (one wave period) in the high time resolution waveform data obtained on these spacecraft. They are thus nonlinear structures generated out of nonlinear instabilities and proc…
The Mid-infrared View of Red Sequence Galaxies in Abell 2218 with AKARI
Goto, Tomotsugu; Kim, Seong Jin; Smail, Ian +16 more
We present the AKARI Infrared Camera (IRC) imaging observation of early-type galaxies (ETGs) in A2218 at zsime 0.175. Mid-infrared (MIR) emission from ETGs traces circumstellar dust emission from asymptotic giant branch (AGB) stars or/and residual star formation. Including the unique imaging capability at 11 and 15 µm, our AKARI data provide…
Determining a tilt in Titan’s north-south albedo asymmetry from Cassini images
West, Robert A.; Nixon, Conor A.; Achterberg, Richard K. +4 more
Analysis of Titan's hemispheric brightness asymmetry from mapped Cassini images reveals an axis of symmetry that is tilted with respect to the rotational axis of the solid body. Twenty images taken from 2004 through 2007 show a mean axial offset of 3.8 ± 0.9° relative to the solid body's pole, directed 79 ± 24° to the west of the sub-solar longitu…
Suzaku Results on the Obscured Low-Luminosity Active Galactic Nucleus in NGC 4258
Makishima, Kazuo; Nakazawa, Kazuhiro; Yamada, Shin'ya +1 more
In 2006 June, the obscured low-luminosity active galactic nucleus in the nearby Seyfert 1.9 galaxy NGC 4258 was observed with Suzaku for ∼100ks. Utilizing the XIS and the HXD, the nucleus emission was detected over a ∼2 to ∼40keV range, with an unabsorbed 2-10keV luminosity of ∼8 × 1040ergs-1; it varied by a factor of ∼2 duri…
On the inverse Compton scattering interpretation of the hard X-ray excesses in galaxy clusters: the case of Ophiuchus
Colafrancesco, S.; Marchegiani, P.
Context: Populations of high energy electrons can produce hard X-ray (HXR) emission in galaxy clusters by up-scattering CMB photons via the inverse Compton scattering (ICS) mechanism. However, this scenario has various astrophysical consequences.
Aims: We discuss here the consequences of the presence of a population of high energy particles fo…
Chandrayaan-1 X-ray Spectrometer (C1XS)—Instrument design and technical details
Grande, M.; Huovelin, J.; Howe, C. J. +13 more
The UK-built Chandrayaan-1 X-ray Spectrometer (C1XS) is flying as an ESA instrument on India's Chandrayaan-1 mission to the Moon. The Chandrayaan-1 mission launched on the 22nd October 2008 and entered a 100 km polar lunar orbit on the 12th November 2008. C1XS builds on experience gained with the earlier D-CIXS instrument on SMART-1, but will be a…
Determination of the cosmic far-infrared background level with the ISOPHOT instrument
Juvela, M.; Lemke, D.; Klaas, U. +3 more
Context: The cosmic infrared background (CIRB) consists mainly of the integrated light of distant galaxies. In the far-infrared the current estimates of its surface brightness are based on the measurements of the COBE satellite. Independent confirmation of these results is still needed from other instruments.
Aims: In this paper we derive esti…
The globular cluster NGC 6642: evidence for a depleted mass function in a very old cluster
Santiago, B. X.; Balbinot, E.; Bonatto, C. +1 more
We present photometry for the globular cluster NGC6642 using the F606W and F814W filters with the Advanced Camera for Surveys in the Wide Field Channel (ACS/WFC) third generation camera on board of Hubble Space Telescope. The colour-magnitude diagram shows sources reaching ~6mag below the turn-off in mF606W. A theoretical isochrone fitt…
Nuclear interaction gamma-ray lines from the Galactic center region
Cheng, K. S.; Ip, W. H.; Tatischeff, V. +3 more
Aims. The accretion of stars onto the central supermassive black hole at the center of the Milky Way is predicted to generate large fluxes of subrelativistic ions in the Galactic center region. We analyze the intensity, shape, and spatial distribution of de-excitation gamma-ray lines produced by nuclear interactions of these energetic particles wi…
Upper Atmosphere and Ionosphere of Saturn
Moses, Julianne I.; Moore, Luke; Miller, Steve +5 more
This chapter summarizes our current understanding of the upper atmosphere and ionosphere of Saturn. We summarize the available observations and the various relevant models associated with these regions. We describe what is currently known, outline any controversies and indicate how future observations can help in advancing our understanding of the…