منابع مشابه
Cold Flows and the First Quasars
Observations of the most distant bright quasars imply that billion solar mass supermassive black holes (SMBHs) have to be assembled within the first 800 million years. Under our standard galaxy formation scenario such fast growth implies large gas densities providing sustained accretion at critical or supercritical rates onto an initial black hole seed. It has been a long standing question whet...
متن کاملRelativistic Flows at the Hotspots of Radio Galaxies and Quasars?
We review the broad band properties of X-ray detected hotspots in radio galaxies and quasars. We show that their collective spectral properties can be unified in a framework involving frequency dependent relativistic beaming and varying orientations to the observer’s line of sight. The simplest dynamic model consistent with this picture is a slowing-down relativistic flow downstream from the ho...
متن کاملA complex network representation of wind flows.
Climate networks have proven to be a valuable method to investigate spatial connectivity patterns of the climate system. However, so far such networks have mostly been applied to scalar observables. In this study, we propose a new method for constructing networks from atmospheric wind fields on two-dimensional isobaric surfaces. By connecting nodes along a spatial environment based on the local...
متن کاملCooling Flows and Quasars: II. Detailed Models of Feedback Modulated Accretion Flows
Most elliptical galaxies contain central black holes (BHs), and most also contain significant amounts of hot gas capable of accreting on to the central BH due to cooling times short compared to the Hubble time. Why therefore do we not see AGNs at the center of most elliptical galaxies rather than in only (at most) a few per cent of them? We propose here the simple idea that feedback from accret...
متن کاملThe radio properties of type II quasars
Abstract. Quasars (of type I) are the luminous analogs of type I Seyfert galaxies. Within the framework of unified models of active galaxies, the population of quasars of type II recently discovered with the Sloan Digital Sky Survey are the luminous analogs of type II Seyfert galaxies. Since our knowledge and understanding of the radio properties of these type II quasars are very limited, we ha...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1986
ISSN: 0074-1809
DOI: 10.1017/s0074180900153069