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Suprathermal ions ahead of interplanetary shocks: New observations and critical instrumentation required for future space weather monitoring
Galvin, A. B.; McComas, D. J.; Schwadron, N. A. +2 more
We report new findings on the low-energy ion population associated with interplanetary (IP) shocks based on Wind/Suprathermal Ion Composition Spectrometer (STICS) observations. Suprathermal ions (6-200 keV) are present in the upstream region of most (86%) IP shocks at 1 AU. These foreshock ions are characterized by (1) median energy >25 keV, th…
M Dwarfs from Hubble Space Telescope Star Counts. V. The I-Band Luminosity Function
Gould, Andrew; Salim, Samir; Bahcall, John N. +2 more
We derive the disk I-band luminosity function from the Zheng et al. sample of ~1400 disk M dwarfs observed with the Hubble Space Telescope. We adopt a Galactic-height-dependent color-magnitude relation to account for the metallicity gradient above the Galactic plane. The resultant I-band luminosity function peaks at MI~9.5 and drops sha…
XMM-Newton observations of the eclipsing polar EP Dra
Cropper, Mark; Ramsay, Gavin; Priedhorsky, W. +3 more
We present XMM-Newton observations of the eclipsing polar EP Dra that cover nearly three binary orbital cycles. The X-ray and ultraviolet data show evidence for a prominent dip before the eclipse, which is due to the accretion stream obscuring the accretion region. The dip ingress is rapid in hard X-rays, suggesting that there is a highly collimat…
An Ion-Cyclotron Resonance-driven Three-Fluid Model of the Slow Wind near the Sun
Chen, Y.; Li, X.
A three-fluid slow wind consisting of electrons, protons, and O+5 ions is constructed to account for a recent UVCS/SOHO observation. In this model, ion-cyclotron waves, which are assumed to be generated by a Kolmogorov turbulent cascade, are assumed to play a key role in driving the slow solar wind. By reproducing recent measurements on…
XMM-Newton spectroscopy of high-redshift quasars
Córdova, F. A.; Mason, K. O.; Puchnarewicz, E. M. +2 more
We present XMM-Newton X-ray spectra and optical photometry of four high-redshift (z= 2.96-3.77) quasars, [HB89] 0438-436, [HB89] 2000-330, [SP89] 1107+487 and RX J122135.6+280613 of these four objects, the first two are radio-loud and the last two are radio-quiet. Model fits require only a power law with Galactic absorption in each case; additiona…
Cluster observations of quasi-periodic impulsive signatures in the dayside northern lobe: High-latitude flux transfer events?
Balogh, A.; Khurana, K. K.; Fazakerley, A. N. +4 more
We report on a series of quasi-periodic reversals in GSM BZ observed by the four Cluster spacecraft in the northern dayside lobe poleward of the cusp on 23 February 2001. During an interval of about 35 min, multiple reversals (negative to positive) in BZ of approximately 1-min duration with an approximate 8-min recurrence tim…
Latitudinal transport effects on the modulation of a few-MeV cosmic ray electrons from solar minimum to solar maximum
Fichtner, H.; Wibberenz, G.; Ferreira, S. E. S. +2 more
A three-dimensional, steady state, numerical model was used to model the propagation of 7 MeV jovian and galactic electrons in the heliosphere. The computations are compared with 3-10 MeV Ulysses/KET electron observations which are still not well explained after ∼1998. To explain these observations, coinciding with solar maximum conditions, it is …
A New Unidentified Far-Infrared Band in NGC 7027
Cernicharo, José; Goicoechea, Javier R.; Masso, Helena +1 more
We report on the detection of a molecular band centered at ~98 µm (~102 cm-1), observed with the Infrared Space Observatory in the young planetary nebula NGC 7027. The band structure and intensity cannot be reproduced by atomic fine-structure lines, recombination lines, or the rotational emission of abundant molecules. We discuss …
The Magnetostatic Cleanliness Program for the Cassini Spacecraft
Narvaez, P.
The Cassini spacecraft, launched in October 1997 and expected to reach Saturn in 2004, carries two magnetometer experiments on a 10-m boom, one at the mid-section of the boom and the other situated at the end of the boom. In order to gather valid scientific magnetic field data and avoid electromagnetic interference, the spacecraft had to comply wi…
A Mid-Infrared Survey of L1641N with ISOCAM
Noriega-Crespo, Alberto; Ali, Babar
We present the results from our analysis of the Infrared Space Observatory (ISO) data on the L1641N outflow region located in the Orion A molecular cloud. The data were obtained with the array camera (ISOCAM) using two broadband filters, LW2 (6.7 µm) and LW3 (14 µm), and the narrowband circular variable filter (CVF), which provides low…