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Apex diagrams for the stellar population of the solar neighborhood

Vereshchagin, S. V.; Reva, V. G.; Chupina, N. V.

We have studied some kinematic features of the coronas of near-solar stellar streams, based on Hipparcos observations. Apex diagrams for kinematic streams, open clusters, and field stars are plotted. In our analysis, we used the apex-diagram (AD) method we developed earlier. We find that the Eggen streams and Arcturus stream have similar propertie…

Flare Loop Sizes in Young Suns

Schultz, J.; Nevalainen, J.; Väänänen, M. K.

We analyse 27 solar flares observed with GOES and RHESSI in the X-ray bands at 3.1--24.8 keV and 12--25 keV and in Hα . The flaring region diameter in X-rays is found to correlate with the Hα decay duration, and this correlation is used to approximate the flare loop semilength. We propose the method to measure the coronal loop semilengths in young…

Structural Analysis of A2034 Clusters of Galaxies

Hudaverdi, M.; Ercan, E. N.; Bozkurt, M.

We present the analysis of X-ray and optical observations of Abell 2034. It is located at the moderate redshift of z=0.113. X-ray data are taken from the XMM-Newton archive. The best-fit single temperature of 7.6 keV model well defines the diffuse hot plasma. The cluster is observed by ground based optical Turkish National Observatory RTT-150 tele…

Coronal dynamics and heating theories

Gudiksen, Boris V.

A large number of coronal heating theories have been proposed and most of them can be labeled as AC or DC heating theories. Here a short description of these two main theories is given, and the results of a DC heating model simulation is explained in more detail. As a result of that model, arguments are given for putting emphasis on launching a ve…

Polycyclic aromatic hydrocarbon selected galaxies

Siebenmorgen, R.; Haas, M.; Chini, R. +3 more

Context: This is the fourth in a series of papers based on the ISOCAM Parallel Survey at 6.7 µm. While the first three papers have been devoted to active galactic nuclei (AGN), here we report on emission-line galaxies without AGN signatures in their optical spectra.
Aims: Polycyclic aromatic hydrocarbon (PAH) emission has been found in b…

Revealing Probable Universal Features in the Lower Red Giant Branch Luminosity Functions of Galactic Globular Clusters

Kravtsov, V. V.

This paper aims at demonstrating, for the first time, very probable universal peculiarities of the evolution of stars in the lower red giant branch (RGB) of Galactic globular clusters (GCs), reflected in two corresponding dips in the luminosity functions (LFs). By relying on the database of Hubble Space Telescope photometry of GCs, we analyze the …

X-Ray Analysis of Galactic SNR G27.4+0.0

Hudaverdi, M.; Ercan, E. N.; Sezer, A. +2 more

In this work, we present X-ray analysis result of SNR G27.4+0.0 observed by XMM-Newton satellite. Three EPIC detectors are studied comparatively. The spatial and spectral analysis are performed, 0.3-10 keV (all band). In order to define possible distribution of interested abundances soft, medium and hard X-ray images are constructed. NEI (Non-equi…

GRB observed by IBIS/PICsIT in the MeV energy range

Götz, D.; Foschini, L.; Di Cocco, G. +5 more

We present the preliminary results of a systematic search for GRB and other transients in the publicly available data for the IBIS/PICsIT (0.2-10 MeV) detector on board INTEGRAL. Lightcurves in 2-8 energy bands with time resolution from 1 to 62.5 ms have been collected and an analysis of spectral and temporal characteristics has been performed. Th…

Hard X-ray flux from low-mass stars in the Cygnus OB2 association

Micela, G.; Drake, J. J.; Flaccomio, E. +1 more

Context: The Cygnus OB2 association, the central engine of the Cygnus X star-forming region, is the subject of an extensive INTEGRAL Key Project that will accumulate 6Ms of observations. Analysis of 2Ms of observations by De Becker and co-workers provides the most sensitive limit yet obtained on hard X-ray emission from the cluster.
Aims: We i…

Streaming Circumnuclear Gas of the Seyfert 2 Galaxy NGC 5728

Ferruit, Pierre; Hyung, Siek; Son, Dong-Hoon +1 more