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The First Optical Validation of an X-Ray Line-emitting Object: A Detection in the XMM-Newton Observation of the Chandra Deep Field-South
Braito, V.; Caccianiga, A.; Severgnini, P. +2 more
We present the first optical validation of an X-ray line-emitting object (XLEO) discovered in the XMM-Newton observation of the Chandra Deep Field-South. The object is an active galactic nucleus at zX~0.66. An optical spectrum of the source indeed confirms and refines (zo=0.665) the redshift obtained from the X-ray line. The …
The HST Cosmos Project: Contribution from the SUBARU Telescope
Aussel, H.; Sanders, D. B.; Murayama, T. +16 more
The Cosmic Evolution Survey (COSMOS) is a Hubble Space Telescope (HST) treasury project.The COSMOS aims to perform a 2 square degree imaging survey of an equatorial field in $I$(F814W) band, using the Advanced Camera for Surveys (ACS). Such a wide field survey, combined with ground-based photometric and spectroscopic data, is essential to understa…
Evolution of Barb Angle and Filament Eruption
Liu, Y.; Li, C.; Zhang, H. Q. +6 more
Hα observations of a quiescent U-shaped filament were obtained at Big Bear Solar Observatory and at Hida Observatory with the Flare Monitoring Telescope. The filament was located in the southern hemisphere on 1998 November 4. We study the evolution of the angle of a barb with respect to the axis of the filament and find the evolution can be divide…
Pre-Main Sequence Stars Seen by ISO
Lorenzetti, Dario
Observations of pre-main sequence objects (T Tauri, Herbig Ae/Be and FU Orionis stars) obtained with the instrumentation on board the Infrared Space Observatory (ISO) are reviewed. All the observations have been mainly carried out by using the two spectrographs SWS and LWS, adopting their low resolution modes and such data have been used both for …
Temporal variations in the magnetic network large-scale dynamics
Meunier, N.
The variation in the magnetic network large-scale dynamics is investigated using MDI magnetograms from 1996 to 2004. Cross-correlation and feature tracking techniques are used on pairs of magnetograms in order to derive the dynamics at the solar surface, including magnetic network regions. The variations for both methods are very different, the fe…
The extent of 3-min oscillations in regions other than sunspot plumes
Doyle, J. G.; Banerjee, D.; O'Shea, E. +1 more
The active region, AR0554, was observed with NIS/CDS on board SoHO to examine the extent and range of oscillations from a range of features. Among all the NIS spectral lines analysed, significant oscillations were found in Si xii 520 Å, Mg x 625 Å, O v 629 Å, and He i 522 Å. The periods of the strongest oscillations in these lines were ≈10-20 min.…
Pseudo-field line resonances in ground Pc5 pulsation events
Sarafopoulos, D. V.
In this work we study four representative cases of Pc5 ground pulsation events with discrete and remarkably stable frequencies extended at least in a high-latitude range of ~20°; a feature that erroneously gives the impression for an oscillation mode with "one resonant field line". Additionally, the presented events show characteristic changes in …
Magnetospheric plasma boundaries: a test of the frozen-in magnetic field theorem
Lundin, R.; Yamauchi, M.; Sauvaud, J. -A. +1 more
The notion of frozen-in magnetic field originates from H. Alfvén, the result of a work on electromagnetic-hydrodynamic waves published in 1942. After that, the notion of frozen-in magnetic field, or ideal MHD, has become widely used in space plasma physics. The controversy on the applicability of ideal MHD started in the late 1950s and has continu…
Ab initio oscillator strengths and transition probabilities of transitions from 2s 22p 23l and 2s2p 33l in S X
Karpuškienė, R.; Bogdanovich, P.; Udris, A.
Ab initio energy spectra of the ground configuration 2s 22p 3 and the excited configurations 2s2p 4, 2p 5, 2s 22p 23s, 2s 22p 23p, 2s 22p 23d, 2s2p 33s, 2s2p 33p, and 2s2p 33d of nitrogen-like sulphur S X h…
Nonradial and nonpolytropic astrophysical outflows. VII. Fitting ULYSSES solar wind data during minimum
Tsinganos, K.; Iro, N.; Lima, J. J. G. +1 more
Exact axisymmetric analytical solutions of the governing MHD equations for magnetized and rotating outflows are applied to the solar wind during solar minimum as observed by ULYSSES. Using the spacecraft data, the latitudinal dependences of physical quantities such as the density, velocity, magnetic field and temperature are analytically described…