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Akademie věd České republiky |
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Akademie věd České republiky |
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Pravidelný seminář 24. 4. 2006
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který se koná v pondělí dne v zasedací místnosti Kosmické laboratoře AsÚ v Ondřejově PROGRAM: 13:00 odborná část V odborné části vyslechneme přednášku: Accretion onto massive
black holes
Prof. Bozena Czerny (Copernicus Astronomical Center, Warsaw) Accretion onto massive black holes is generally accepted as a way to power strong non-stellar emission from active galactic nuclei. However, our level of understanding of the flow pattern seems to be a decreasing function of the luminosity to the Eddington luminosity ratio. Standard disk accretion model is roughly satisfactory for bright quasars and some Narrow Line Seyfert 1 galaxies (L/L_Edd about 1), various models of hard X-ray emission can account for fainter quasars and Seyfert 1 galaxies (L/L_Edd about 0.01), although serious problems remain, the radiatively inefficient inflow/outflow with high angular momentum may, or may not, account for Low Luminosity AGN (L/L_Edd about 0.0001), and global flow pattern in the case of accretion onto Sgr A* remains an open question. I will argue that in this case low angular momentum flow offers a natural and attractive possibility. Srdečně zve Vladimír Karas vedoucí semináře |