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XMM-Newton temperature maps for five intermediate redshift clusters of galaxies
Durret, Florence; Lima Neto, Gastão B.
We have analyzed XMM-Newton archive data for five clusters of galaxies (redshifts 0.223 0.313) covering a wide range of dynamical states, from relaxed objects to clusters undergoing several mergers. We present here temperature maps of the X-ray gas together with a preliminary interpretation of the formation history of these clusters.
Enhanced p-Mode Absorption Seen Near the Sunspot Umbral Penumbral Boundary
Mathew, Shibu K.
We investigate p-mode absorption in a sunspot using SOHO/MDI high-resolution Doppler images. The Doppler power computed from a 3.5-hour data set is used for studying the absorption in a sunspot. The result shows an enhancement in absorption near the umbral - penumbral boundary of the sunspot. We attempt to relate the observed absorption with the m…
Advanced method to derive the IMF direction near Mars from cycloidal proton distributions
Kallio, E.; Fedorov, A.; Barabash, S. +7 more
In a previous paper, we showed a method for deriving the interplanetary magnetic field (IMF) orientation from the velocity distribution of ring-like distributed ions as measured by the Ion Mass Analyser (IMA) on board Mars Express (MEX). This method has been improved so that one can derive the IMF orientation from a very limited portion of the rin…
Physical and kinematical properties of the X-ray absorber in the broad absorption line quasar APM 08279+5255
Ramírez, J. M.
Context: We have re-analyzed the X-ray spectra of the gravitational lensed high-redshift BAL QSO APM 08279+5255, observed with the XMM-Newton and Chandra observatories. Previous studies (Hasinger et al. 2002, ApJ, 573, L77; Chartas et al. 2002, ApJ, 579, 169) detected unusual, highly-ionized iron absorption features, but differed in their interpre…
Post-hoc derivation of SOHO Michelson doppler imager flat fields
Potts, H. E.; Diver, D. A.
Context: The SOHO satellite now offers a unique perspective on the Sun as it is the only space-based instrument that can provide large, high-resolution data sets over an entire 11-year solar cycle. This unique property enables detailed studies of long-term variations in the Sun. One significant problem when looking for such changes is determining …
Probing the nature of IGR J16493-4348: spectral and temporal analysis of the 1-100 keV emission
de Rosa, A.; Hill, A. B.; Bird, A. J. +5 more
IGR J16493-4348 was one of the first new sources to be detected by the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) γ-ray telescope in the 18-100 keV energy band. Based on spatial coincidence, the source was originally associated with the free radio pulsar PSR J1649-4349. Presented here are the results of 2.8 Ms of observations made …
The angular separation of the components of the Cepheid AWPer
Massa, D.; Evans, N. R.
The 6.4d classical Cepheid AWPer is a spectroscopic binary with a period of 40yr. Analysing the centroids of Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) spectra obtained in 2001 November, we have determined the angular separation of the binary system. Although we currently have spatially resolved data for a single epoch …
Gnevyshev Peaks and Gaps for Coronal Mass Ejections of Different Widths Originating in Different Solar Position Angles
Kane, R. P.
The sunspot number series at the peak of sunspot activity often has two or three peaks (Gnevyshev peaks; Gnevyshev, Solar Phys.1, 107, 1967; Solar Phys.51, 175, 1977). The sunspot group number (SGN) data were examined for 1997 - 2003 (part of cycle 23) and compared with data for coronal mass ejection (CME) events. It was noticed that they exhibite…
Resolving Spacecraft Earth-Flyby Anomalies with Measured Light Speed Anisotropy
Cahill, Reginald T.
Doppler shift observations of spacecraft, such as Galileo, NEAR, Cassini, Rosetta and MESSENGER in earth flybys, have all revealed unexplained speed `anomalies' - that the doppler-shift determined speeds are inconsistent with expected speeds. Here it is shown that these speed anomalies are not real and are actually the result of using an incorrect…
Tailward propagation of Pi2 waves in the Earth's magnetotail lobe
Balogh, A.; Nakamura, R.; Baumjohann, W. +3 more
Pi2 waves are an intergral part of the substorm process and have been observed on the ground and in space. Using the special ability of Cluster to determine the propagation direction of signals measured in the magnetometer data, it is found that in the lobes of the Earth's magnetotail, for the cases in this study, the Pi2 waves are travelling tail…