Search Publications
An empirical model of Saturn's bow shock: Cassini observations of shock location and shape
Coates, A. J.; Dougherty, M. K.; Hospodarsky, G. B. +4 more
We present a new empirical model of Saturn's bow shock that utilizes observations from the Cassini spacecraft. Shock crossings are identified in magnetic field and plasma observations made by Cassini between June 2004 and August 2005. The Cassini crossings are then combined with the crossings made during the Saturn flybys of Pioneer 11, Voyager 1,…
A New Hubble Space Telescope Distance to NGC 1569: Starburst Properties and IC 342 Group Membership
Mack, Jennifer; Aloisi, Alessandra; van der Marel, Roeland P. +8 more
We present deep HST ACS/WFC photometry of the dwarf irregular galaxy NGC 1569, one of the closest and strongest nearby starburst galaxies. These data allow us, for the first time, to unequivocally detect the tip of the red giant branch and thereby determine the distance to NGC 1569. We find that this galaxy is 3.36 +/- 0.20 Mpc away, considerably …
XMM-Newton Observations of Radio Pulsars B0834+06 and B0826-34 and Implications for the Pulsar Inner Accelerator
Haberl, F.; Zhang, B.; Gil, J. +3 more
We report the X-ray observations of two radio pulsars with drifting subpulses, B0834+06 and B0826-34, using XMM-Newton. PSR B0834+06 was detected with a total of 70 counts from the three EPIC instruments over 50 ks exposure time. Its spectrum is best described as that of a blackbody (BB), with temperature Ts = (2.0+ 2.0-…
Induced magnetosphere and its outer boundary at Venus
Barabash, S.; Russell, C. T.; Wei, H. Y. +8 more
The induced magnetosphere at Venus consists of regions near the planet and its wake for which the magnetic pressure dominates all other pressure contributions. Initial Venus Express measurements indicate a well-defined outer boundary, the magnetopause, of the induced magnetosphere. This magnetopause acts as an obstacle to deflect the solar wind. A…
Characterizing the Near-UV Environment of M Dwarfs
Hawley, Suzanne L.; Johns-Krull, Christopher M.; Walkowicz, Lucianne M.
We report the results of our Hubble Space Telescope (HST) snapshot survey with the ACS HRC PR200L prism, designed to measure the near-UV emission in a sample of nearby M dwarfs. Thirty-three stars were observed, spanning the mass range from 0.1 to 0.6 solar masses (Teff ~ 2200-4000 K) where the UV energy distributions vary widely betwee…
High-Resolution Mapping of Flows in the Solar Interior: Fully Consistent OLA Inversion of Helioseismic Travel Times
Birch, A. C.; Gizon, L.; Jackiewicz, J.
To recover the flow information encoded in travel-time data of time - distance helioseismology, accurate forward modeling and a robust inversion of the travel times are required. We accomplish this using three-dimensional finite-frequency travel-time sensitivity kernels for flows along with a (2+1)-dimensional (2+1D) optimally localized averaging …
INTEGRAL discovery of non-thermal hard X-ray emission from the Ophiuchus cluster
Paltani, S.; Eckert, D.; Produit, N. +2 more
We present the results of deep observations of the Ophiuchus cluster of galaxies with INTEGRAL in the 3-80 keV band. We analyse 3 Ms of INTEGRAL data on the Ophiuchus cluster with the IBIS/ISGRI hard X-ray imager and the JEM-X X-ray monitor. In the X-ray band using JEM-X, we show that the source is extended, and that the morphology is compatible w…
High-latitude Earth's magnetopause outside the cusp: Cluster observations
RèMe, H.; Korth, A.; Büchner, J. +4 more
We investigated the ambient plasma and magnetic field conditions at high latitudes, as well as the macroparameters of the magnetopause. For this purpose we used Cluster spacecraft plasma and magnetic field data when all the interspacecraft distances were less than 300 km. We analyzed 154 magnetosheath-magnetosphere transitions which allow to disti…
INTEGRAL observations of the blazar Mrk 421 in outburst. Results of a multi-wavelength campaign
Lähteenmäki, A.; Ajello, M.; Horan, D. +15 more
Context: If one wants to understand the physics of blazars, better simultaneous observations are important at all wavelengths, so it was fortunate that a ToO observation of the TeV-emitting blazar Mrk 421 with INTEGRAL could be triggered in June 2006 by an increase in the RXTE count rate to more than 30 mCrab. The source was then observed with all…
Rotational Feature of Vega Revealed from Spectral Line Profiles
Takeda, Yoichi; Kawanomoto, Satoshi; Ohishi, Naoko
In order to establish Vega's absolute rotational velocity, ve, as distinct from the inclination angle, i, we conducted a detailed profile study on a large number (~200) of weak lines based on very high signal-to-noise ratio spectrum data, making use of the fact that the lines' characteristic shapes may contain information about rotation…