Seminarium środowe

"Jets in accreting black-hole binaries"

Andrzej Zdziarski (Copernicus Astronomical Center, Warsaw)

The most spectacular jets are observed from active galactic nuclei, in particular, from quasars. However, highly interesting jets are also launched by accretion flows in stellar binaries containing a normal star accreting onto a stellar-mass black hole. Such systems are analogs of quasars on a much smaller scale and are called microquasars. There are two distinctly different types of jets in microquasars. Jets of the first type are steady and are launched during accretion states characterized by hard X-ray emission. They are launched over weeks to months but are observed only up to maximum distances of about 1/1000 of a parsec. Those of the other type are launched on time scales of only a day during transitions of the accretion flow from the hard to soft spectral states but are observed as moving ejecta up to a parsec scale, i.e., up to ~1000 times larger distances. I will discuss possible causes of this difference, the jet emission mechanisms, collimation, the presence of electron-positron pairs, magnetic fields, bulk Lorentz factors, and the jet power.

"Do astronomical objects create also negative radiation pressure?"

Jarosław Duda (Jagiellonian University, Cracow)

I will discuss possibility of negative radiation pressure e.g. from astronomical objects and how we could observe it, also its different potential applications like medical and computational e.g. 2WQC (two-way quantum computers). Photon sources create positive radiation pressure p=/c being toward surface, pushing it. However, generally it could be also outside surface: pulling it, for example using a process which in T-symmetry perspective (H -> -H) creates positive radiation pressure - like synchrotron radiation generated by charge travelling on a circle, which also does it in T-symmetry perspective. Similar T/CPT symmetry argument suggests that black holes might generate negative radiation pressure. I also will suggest related solution to ANITA anomaly.

"TBA"

Surajit Kalita (Warsaw University Observatory)

"Toward Autonomous Observatories: Development of the Cerro Murphy Observatory Software System"

Mirosław Kicia (CAMK PAN, Warsaw)

"tba"

Pratik Dabhade (National Center for Nuclear Research (NCBJ), Warsaw)