1,721 research outputs found
Observations of Sy2 galaxy NGC 3281 by XMM-Newton and INTEGRAL satellites
We present here the results of our analysis of X-ray properties of Seyfert 2
galaxy NGC 3281, based on the observational data obtained by XMM-Newton and
INTEGRAL within the energy ranges 0.2-12 keV and 20-150 keV, respectively. The
XMM-Newton spectrum of this object is presented for the first time. We show
that fitting the X-ray spectrum of this galaxy with models based on the
reflection from the disc with infinite column density yields non-physical
results. More appropriate fit takes into account both transmitted and reflected
emission, passed through a gas-dusty torus-like structure. Keeping this in
mind, to model the inhomogeneous clumpy torus, we used the MYTorus model.
Hence, we propose that the torus of NGC 3281 is not continuous structure, but
it consists of separate clouds, which is in a good agreement with the results
of near-IR observations. Using this assumption, we found that the torus
inclination angle and the hydrogen column density are 66.98^{+2.63}_{-1.34}
degrees and 2.08^{+0.35}_{-0.18}x10^{24} cm^{-2}, respectively. Also, the
emission of the hot diffuse gas with temperature ~590 eV and warm absorption
were detected.Comment: 8 pages, 5 figures, 2 tables, accepted for publication in Advances in
Astronomy and Space Physic
Hydroxyl emission at high latitudes
Intensity and rotational temperature of hydroxyl emission at high latitudes during winte
Twilight helium emission at high latitudes
Twilight helium emission at high latitudes during winte
Grain refinement in a Cu-Cr-Zr alloy during multidirectional forging
Structural changes during plastic deformation were studied in a Cu-0.3%Cr-0.5%Zr alloy subjected to multidirectional forging up to a total strain of 4 at the temperatures of 300 K and 673 K. The deformation behavior was characterized by a rapid increase in the flow stress at an early deformation followed by a steady-state flow at large strain. The development of the new ultrafine grains resulted from the progressive increase in the misorientations of the strain-induced low-angle boundaries, which evolve into high-angle boundaries with increasing cumulative strain through a strain-induced continuous reaction that is quite similar to continuous dynamic recrystallizatio
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