On Energetics and Structure of Sub-parsec Jets in Quasars

This paper reviews the topic of sub-parsec - scale jets in quasars, and covers the the following issues: observations of parsec and sub-parsec scale jets; energy dissipation and particle acceleration; radiative processes; magnetic fields, pair content, and energetics; and variability and its relation to the central engine activity. In particular, we describe how internal shocks can explain properties of gamma-ray flares and demonstrate that MeV blazars (those with luminosity peak in the 1-30 MeV range) can be unified with GeV blazars (those with luminosity peak at GeV energies) assuming that in GeV blazars the gamma-ray flares are produced via Comptonization of broad emission lines, whereas in the MeV blazars they result from Comptonization of infrared radiation of hot dust. We also make predictions about the radiative effects of bulk Compton process in the soft X-ray band and show how spectral and variability properties in that band can be used to constrain structure of jets near their bases.Comment: To appear in the Proceedings of the 2nd KIAS Astrophysics Workshop "Current High Energy Emission Around Black Holes," Seoul, Korea, Sep. 3 - 8, 2001 (15 pages

Apology of poetics

The article deals with Edward Balcerzan’s book called Pochwała poezji (Praise of poetry ) (Mikoł.w 2013). The author discusses it in the context of modern academic writing, as well as in relation to tradition and today’s autobiographical practice, but above all shows what task does structuralist poetics accomplish and how it influences the interpretation of a literary work.The article deals with Edward Balcerzan’s book called Pochwała poezji (Praise of poetry ) (Mikoł.w 2013). The author discusses it in the context of modern academic writing, as well as in relation to tradition and today’s autobiographical practice, but above all shows what task does structuralist poetics accomplish and how it influences the interpretation of a literary work

Are Quasar Jets Matter or Poynting Flux Dominated?

If quasar jets are accelerated by magnetic fields but terminate as matter dominated, where and how does the transition occur between the Poynting-dominated and matter-dominated regimes? To address this question, we study constraints which are imposed on the jet structure by observations at different spatial scales. We demonstrate that observational data are consistent with a scenario where the acceleration of a jet occurs within 10^{3-4} R_g. In this picture, the non-thermal flares -- important defining attributes of the blazar phenomenon - are produced by strong shocks formed in the region where the jet inertia becomes dominated by matter. Such shocks may be formed due to collisions between the portions of a jet accelerated to different velocities, and the acceleration differentiation is very likely to be related to global MHD instabilities.Comment: to appear in "Astrophysical Sources of High Energy Particles and Radiation", AIP Proceedings Series, eds. T. Bulik, G. Madejski, and B. Rudak (20-24 June 2005, Torun, Poland

Recent and Future Observations in the X-ray and Gamma-ray Bands: Chandra, Suzaku, GLAST, and NuSTAR

This paper presents a brief overview of the accomplishments of the Chandra satellite that are shedding light on the origin of high energy particles in astrophysical sources, with the emphasis on clusters of galaxies. It also discusses the prospects for the new data to be collected with instruments recently launched - such as Suzaku - or those to be deployed in the near future, and this includes GLAST and NuSTAR.Comment: To appear in "Astrophysical Sources of High Energy Particles and Radiation", eds. T. Bulik, B. Rudak, and G. Madejski, AIP Conference Proceedings, vol 801 (2005), proc. conf. in Torun, Poland, 20-24 June 200