Search Publications
Optical Constraints on an X-ray Transient Source in M31
Williams, Benjamin F.; McClintock, Jeffrey E.; Murray, Stephen S. +2 more
We have detected a transient X-ray source in the M31 bulge through a continuing monitoring campaign with the Chandra ACIS-I camera. The source was detected at R.A.=00h42m33.428s+/-0.11", decl.=+41deg17'03.37"+/-0.11" in only a single observation taken 2004 May 23. Fortuitous optical HST ACS imaging of th…
Planetary science: Are there active glaciers on Mars?
Montgomery, David R.; Gillespie, Alan R.; Mushkin, Amit
Observations of the X-ray Burster MX 0836-42 by the INTEGRAL and RXTE Orbiting Observatories
Sunyaev, R. A.; Lutovinov, A. A.; Grebenev, S. A. +1 more
We present the results of our study of the emission from the transient burster MX 0836-42 using its observations by the INTEGRAL and RXTE X-ray and gamma-ray observatories in the period 2003 2004. The source’s broadband X-ray spectrum in the energy range 3 120 keV has been obtained and investigated for the first time. We have detected 39 X-ray bur…
Estimation of Projection Effect of CMEs from the Onset Time of the Shock-Associated Type III Radio Burst
Gopalswamy, N.; Michalek, G.; Yashiro, S.
We present a new possibility to estimate the projection effects on coronal mass ejection (CME) measurements. It is well known that coronagraphic observations of CMEs are subject to projection effects. Fortunately, the WIND/WAVES observations of type III radio bursts associated with shock waves are free from projection effects. We assume that (1) h…
The temperature structure in the core of Sérsic 159-03
Kaastra, J. S.; de Plaa, J.; Tamura, T. +6 more
We present results from a new 120 ks XMM-Newton observation of the cluster of galaxies Sérsic 159-03. In this paper, we focus on the high-resolution X-ray spectra obtained with the Reflection Grating Spectrometer (RGS). The spectra allow us to constrain the temperature structure in the core of the cluster and determine the emission measure distrib…
Magnetospheric physics: Turbulence on a small scale
Goldstein, Melvyn L.
The four-spacecraft Cluster mission has identified small-scale vortices in Earth's magnetosphere. The observation reveals processes that transfer energy and momentum from the solar wind to the magnetosphere.
Hubble Space Telescope Imaging of the WR 38/WR 38a Cluster
Gies, Douglas R.; Moffat, Anthony F. J.; Wallace, Debra J. +2 more
We are conducting a high angular resolution imaging survey of Galactic Wolf-Rayet stars using the Wide Field Planetary Camera 2 aboard the Hubble Space Telescope (HST). We have found a small stellar cluster associated with the faint, close pair WR 38 and WR 38a. We present astrometric measurements and photometry in the wide-band F336W (U), F439W (…
Interplanetary shocks unconnected with earthbound coronal mass ejections
Tappin, S. J.; Howard, T. A.
An associated study by Howard and Tappin (2005) identified 7 Earthbound forward shocks (of which 3 were geoeffective) which were not connected with any detectable coronal mass ejection activity along the Sun-Earth line. This largely unexplored result lends evidence to the fact that some large interplanetary transients are not detected by coronagra…
Flux pile-up and plasma depletion at the high latitude dayside magnetopause during southward interplanetary magnetic field: a cluster event study
Balogh, A.; Lavraud, B.; Rème, H. +3 more
An event of strong flux pile-up and plasma depletion at the high latitude magnetopause tailward of the cusp has been analyzed based on observations by the suite of Cluster spacecraft. The multi-satellite analysis facilitates the separation of temporal and spatial features and provides a direct estimate for the strength of the plasma depletion laye…
Einstein-de Sitter model re-examined for newly discovered Type Ia supernovae
Vishwakarma, R. G.
The consistency of the Einstein-de Sitter model with the Type Ia supernovae (SNe Ia) recently observed by the Hubble Space Telescope is examined. The model shows a reasonable fit to the observations, if account is taken of the extinction of SN light by the intergalactic metallic dust ejected from the SN explosions. Although the fit to the new data…