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Spitzer Space Telescope IRAC and MIPS Observations of the Interacting Galaxies IC 2163 and NGC 2207: Clumpy Emission
Brinks, Elias; Struck, Curtis; Elmegreen, Bruce G. +4 more
IC 2163 and NGC 2207 are interacting galaxies that have been well studied at optical and radio wavelengths and simulated in numerical models to reproduce the observed kinematics and morphological features. Spitzer IRAC and MIPS observations reported here show over 200 bright clumps from young star complexes. The brightest IR clump is a morphologic…
Unveiling the nature of INTEGRAL objects through optical spectroscopy. IV. A study of six new hard X-ray sources
Palazzi, E.; Masetti, N.; Walter, R. +9 more
We present further results from our onging optical spectrophotometric campaign at the Astronomical Observatory of Bologna in Loiano (Italy) on unidentified hard X-ray sources detected by INTEGRAL. We observed spectroscopically the putative optical counterparts of the INTEGRAL sources IGR J00234+6141, IGR J01583+6713, IGR J06074+2205, IGR J13091+11…
A fossil galaxy cluster: an X-ray and optical study of RX J1416.4+2315
Ponman, Trevor J.; Khosroshahi, Habib G.; Maughan, Ben J. +1 more
We present a detailed X-ray and optical study of a distant fossil system RX J1416.4+2315(z ~ 0.137), combining Chandra and XMM-Newton observations, optical photometry and spectroscopy. X-ray emitting hot gas imaged by both the Chandra and XMM-Newton shows a globally relaxed spatial distribution, supporting the idea that fossil groups are old galax…
A simple scale height model of the electron density in Saturn's plasma disk
Gurnett, D. A.; Persoon, A. M.; Kurth, W. S. +1 more
A study of electron densities in Saturn's inner magnetosphere is presented using measurements of the upper hybrid resonance frequency obtained from the Radio and Plasma Wave Science (RPWS) instrument on the Cassini spacecraft. The study uses data from the first 16 months of operation in orbit around Saturn. The distribution of density data spans l…
Solar Mass Ejection Imager (SMEI) observations of coronal mass ejections (CMEs) in the heliosphere
Price, S.; Simnett, G. M.; Webb, D. F. +16 more
The Solar Mass Ejection Imager (SMEI) on the Coriolis spacecraft has been obtaining white light images of nearly the full sky every 102 minutes for three years. We present statistical results of analysis of the SMEI observations of coronal mass ejections (CMEs) traveling through the inner heliosphere; 139 CMEs were observed during the first 1.5 ye…
E ring dust sources: Implications from Cassini's dust measurements
Schmidt, Jürgen; Albers, Nicole; Spahn, Frank +6 more
The Enceladus flybys of the Cassini spacecraft are changing our understanding of the origin and sustainment of Saturn's E ring. Surprisingly, beyond the widely accepted dust production caused by micrometeoroid impacts onto the atmosphereless satellites (the impactor-ejecta process), geophysical activities have been detected at the south pole of En…
Cassini UVIS observations of the Io plasma torus. III. Observations of temporal and azimuthal variability
Delamere, P. A.; Bagenal, F.; Steffl, A. J.
In this third paper in a series presenting observations by the Cassini Ultraviolet Imaging Spectrometer (UVIS) of the Io plasma torus, we show remarkable, though subtle, spatio-temporal variations in torus properties. The Io torus is found to exhibit significant, near-sinusoidal variations in ion composition as a function of azimuthal position. Th…
XMM-Newton X-ray spectroscopy of classical T Tauri stars
Schmitt, J. H. M. M.; Robrade, J.
We present results from a comparative study of XMM-Newton observations of four classical T Tauri stars (CTTS), namely
Simultaneous optical and X-ray observations of a giant flare on the ultracool dwarf LP 412-31
Liefke, C.; Schmitt, J. H. M. M.; Micela, G. +1 more
Cool stars are known to produce flares probably as a result of the magnetic reconnection in their outer atmospheres. We present simultaneous XMM-Newton optical V band and X-ray observations of the M8 dwarf LP 412-31. During the observation a giant flare occurred, with an optical amplitude of 6 mag and total energy of 3 × 1032 erg in bot…
The planetary nebula population of the Sagittarius dwarf spheroidal galaxy
Minniti, D.; Walsh, J. R.; van Hoof, P. A. M. +3 more
The identification of two new planetary nebulae (PNe) in the Sagittarius dwarf spheroidal galaxy (Sgr) is presented. This brings the total number to four. Both new PNe were previously classified as Galactic objects. The first, StWr 2-21, belongs to the main body of Sgr, from its velocity and location. The second, the halo PN BoBn1, has a location,…