Pravidelné semináře pořádáme jednou měsíčně (říjen–červen, zpravidla první pondělí v měsíci) od 13 hod v seminární místnosti pracoviště Ondřejov. (archiv seminářů)
06. 06. 2011
A pan-spectral method of abundance determination
(takes place at the seminar room behind the 2-meter telescope)
Dále pořádáme menší semináře jednotlivých oddělení:
Semináře slunečního oddělení
Každé úterý v 12:45 (září–červen, s výjimkou úterků po celoústavním semináři) v zasedací místnosti slunečního oddělení pracoviště Ondřejov.
31/05/2011, 13:00Electron beams and magnetoacoustic waves propagating from a magnetic null point located in the solar coronaAbstract: We analyze the solar radio event observed in 26 November 2005 by the Giant Metrewave Radio Telescope (GMRT) at 244 and 611 MHz, HiRAS (25-2500 MHz) and at the Learmonth Observatory (radio fluxes at 245, 410, 610, and 1415 MHz). The GMRT observations are used to make interferometric maps of the event at both frequencies with the time cadence of 1 s from 06:50 to 07:12 UT. These maps show that one source at 244 MHz is correlated in time with that on 611 MHz. The magnetic field extrapolation indicates that both these sources are connected through a magnetic null point located in the corona. The time-evolution of these radio sources is consistent with an electron acceleration site located at this null point and electron beams propagating from this site to both correlated sources. Using the wavelet method we analyze light curves at all frequencies. These wavelet power spectra show long as well as short period variations with periods in the range P = 215-304 s and P = 7-93 s, respectively. Furthermore, for the correlated sources at 244 and 611 MHz we found the wavelet patterns with the period of about P = 80 s in the form of tadpoles. They indicate that the magnetoacoustic waves (similarly as electron beams, but with much lower velocities) propagate from a wave initiation site (probably the same as beam acceleration site) to sources which are thus correlated. Considering these electron-beam and magnetosonic-wave processes we estimated the basic plasma parameters in the radio sources.
Zářivě-(magneto)hydrodynamické semináře
Zpravidla 1x za 14 dní ve čtvrtek od 11 hod (říjen–červen) v zasedací místnosti slunečního oddělení pracoviště Ondřejov.
26.5.2011, 11:00Masaryk University, BrnoCalculation of partition functions for stellar atmospheres
Semináře oddělení GPS
Zpravidla v knihovně pracoviště Praha–Spořilov v různé dny.
20. 06. 2011, 14:00Department of Physics, Hiroshima University, JapanRecoil velocity induced by electromagnetic radiationAbstract: We examine the recoil velocity induced by the superposition of the magnetic dipole and quadrupole radiation from a pulsar/magnetar born with rapid rotation. The resultant velocity depends not on the magnitude, but rather the ratio of the two moments and their geometrical configuration. The model does not necessarily lead to high spatial velocity for a magnetar with a strong magnetic field, which is consistent with the recent observational upper bound. The maximum velocity predicted with this model is slightly smaller than that of observed fast-moving pulsars.(Takes place at: Sporilov library)