Main research and development work completed in 2011 and ready for implementation
Satellite data usage for understanding of the hot plasma transport in the fusion devices
The turbulent boundary layers (TBL) in the fusion devices and at the magnetospheric plasma boundaries have similar
structure function features (scalings etc., see the Figure), intermittency and anomalous transport features
(e.g., superdiffusion), produced by the extreme flux bursts, which are statistically described by the log-Poisson
cascade model with the quasi-one-dimensional dissipative structures. Satellite measurements, in contrast to that of
the laboratory ones, provide by the order of magnitude better space resolution due to the sensors’ dimensions being much less of that of the plasma characteristic sizes. Being limited in the number of the measurement points (i.e. by the satellite number), the space experiments correspondingly enrich that of the laboratory ones, where, practically unlimited number of the probes disturb the natural plasma due to their finite dimensions, which, in turn, diminishes the measurement accuracy.
S. Savin, V. Budaev, L. Zelenyi
- V P Budaev, S P Savin, L M Zelenyi, Investigation of intermittency and generalized self-similarity of turbulent boundary layers in laboratory and magnetospheric plasmas: towards a quantitative definition of plasma transport features, Physics - Uspekhi, 54 (9) 875 - 918 (2011)
- S. Savin, V. Budaev, L. Zelenyi, E. Amata, D. Sibeck et al., Anomalous plasma flow interactions with boundary layers of geomagnetic trap, JETP Letters, 2011, Vol. 93, No. 12, pp. 754–762. (Original Russian Text © S. Savin, V. Budaev, L. Zelenyi, E. Amata, D. Sibeck, V. Lutsenko, N. Borodkova, H. Zhang, V. Angelopoulos, J. Safrankova, Z. Nemecek, J. Blecki, J. Buechner, L. Kozak, S. Romanov, A. Skalsky, V. Krasnoselsky, 2011, published in Pis’ma v Zhurnal Eksperimental’noi i Teoreticheskoi Fiziki, 2011, Vol. 93, No. 12, pp. 837–846. 2011.
(IKI RAS together with “Kurchatov Institute”)
On the nature of X-ray and gamma-ray radiation from the Galactic Center region
Using the INTEGRAL observatory, researchers investigated Galactic emission in the 511 keV and 1.8 MeV lines, associated with annihilation of electron-positron pairs and decay of the radioactive isotope 26Al synthesized by massive stars. It is found that the 1.8 MeV line is concentrated in the Galactic disk, whereas positron annihilation takes place in the central region of the Galaxy. It is demonstrated that the positrons are likely produced during type 1a supernova explosions and annihilate upon cooling of the interstellar medium to 10,000 degrees.
E. Churazov, S. Sazonov, S. Tsygankov, R. Sunyaev, D. Varshalovich, 2011 «Positron annihilation spectrum from the Galactic Centre region observed by SPI/INTEGRAL revisited: annihilation in a cooling ISM?», MNRAS, 411, 1727.
Fig. Spectra of gamma-ray radiation measured by INTEGRAL from the Galactic bulge and disk. In the bulge spectrum, there is a positron annihilation line at 511 keV. In the disk spectrum, a line at 1.8 MeV dominates, which is produced during decay of 26Al synthesized by massive stars. Also shown is a theoretical model taking into account two-photon annihilation and three-photon decay of positronium.
The Chandra telescope detected X-rays from a region of 1 degree angular size near the supermassive black hole in the Galactic Center. A hypothesis is put forward that this radiation is produced by several thousands of low-mass stars hiding there. Due to close mutual fly-bys, the stars should be rapidly rotating and have coronae producing powerful X-ray radiation. As a consequence, the accretion rate of gas onto the central black hole should be yet lower than believed before.
S. Sazonov, R. Sunyaev, M. Revnivtsev “Coronal radiation of a cusp of spun-up stars and the X-ray luminosity of Sgr A*", MNRAS (in press)
Fig. Spectrum of X-ray radiation from the Galactic Center region measured by the Chandra observatory. It can be described by a model of plasma emission with a temperature of 30 mln degrees. Apart from emission lines of strongly ionized iron, there is a 6.4 keV line, likely associated with fluorescence in stellar photospeheres irradiated by hard coronal radiation. For comparison, models of X-ray spectra of the coronally active stars V711 Tau (blue) and 47 Cas B (red) are shown.
Evidence of Water Vapor in Excess of Saturation in the Atmosphere of Mars
Infrared channel of SPICAM experiment onboard Mars-Express has been developed in IKI RAS and Service d’Aeronomie
(France) to measure water vapor in the Martian atmosphere. The analysis of solar occultation data at limb of the planet allows to study for the first time seasonal changes of water vapor vertical distribution and properties of aerosol particles that is important for the cloud formation process and climate of the planet. A large set of vertical profiles shows substantial supersaturation of water vapor in the atmosphere at altitudes of 30-40 km. This finding contradicts the canonical assumption that atmospheric water on Mars cannot exist in a supersaturated state. The supersaturation allows a large amount of water to access high altitudes above the hygropause (saturation level) that is a fundamental value for water transport and seasonal redistribution between asymmetric northern and southern hemispheres of Mars.
This result has a key value for Martian general circulation models.
Figure 1. Saturation ratio from SPICAM IR measurements (a): Northern hemisphere; (b): Southern hemisphere. The vertical line marks the value of 1, which corresponds to the saturated state.
L. Maltagliati, F. Montmessin, A. Fedorova, O. Korablev, F. Forget, J.-L Bertaux, Evidence of water vapor in excess of saturation in the atmosphere of Mars, Science 333, 1868-1871, 2011.
Fedorova A.A., Korablev O.I., IKI RAS
Superfine structure of active galactic nucleus
We are investigated superfine structure of the nucleus of radio galaxy M87 and the quasar 1803+784 with resolution until 20 µas.
It is shown that external matter of M 87 is accreting on the disk, moving along of arms towards to a center and ejecting a bipolar outflow: the jet and the counter-jet. The central high-velocity bipolar outflow is surrounded by the low-velocity helix structure. The high velocity jet is ejected from the central region of the disc, the diameter of which is 4 mpc. The low-velocity part is ejected from the outer region of the disc, diameter of it is 70 mpc, Fig. 1. Relativistic electrons of the jet are accelerated that determined its synchrotron emission at log distance.
Fig.1. Radio galaxy M87: a disk visible of the edge and bipolar outflow surrounding by helix structure
Visible size of the disk of the 1803+784 is equal 1.4 pc, Fig. 2. The relativistic plasma jet is surrounded by helical structure visible like two chains of component - tangential directions of helix. Polarization of radiation of the disk has radial orientation that corresponds to the circular magnetic field. The magnetic field of the jet is oriented parallel to the stream.
Fig.2. A nuclei of the 1803+784: disk with radial orientation of polarization and jet surrounding by helix structure.
Fine Core–Jet Structure of the Galaxy M87, L. I. Matveyenko, S. V. Seleznev, Astronomy Letters, 2011, Vol. 37,Vol. 37, No . 3.
Ejector and Bipolar Outflow of the Radio Galaxy M87, L. I. Matveyenko, S. V. Seleznev, Astronomy Letters , 2011, Vol. 37, No. 8.
Early cycle of matter in active region of star formation, and AGN objects, Matveenko L.I., Sivakon S.S., Seleznev S.V. et al, Proceedings of Science.10-th European VLBI Network Symposium and EVN Users Meeting: VLBI and new generation and of radio arrays. Manchester, UK, September 20-24, 2010.
Main research and development work completed in 2010 and ready for implementation
Main research and development work completed in 2009 and ready for implementation
Main research and development work completed in 2008 and ready for implementation