////how black hole accretion works is well established in general, yet
several rather crucial details remain either not sufficiently understood or are too complex to be studied even by the most powerful present-day computers. To deal with this seemingly hopeless situation, several purely phenomenological approaches have been adopted. Two of them should...
Although the main focus of this review is on black hole accretion disk theory, we note that there has long been a strong observational connection between accreting black holes and relativistic jets across all scales of black hole mass. For supermassive black holes this includes quasars and active galactic nuclei; for stellar-mass black holes this includes microquasars. However, the theoretical understanding of disks and jets has largely proceeded separately and the physical link between the two still remains uncertain...
Naty1 said:In case an expert with an answer does not appear, here is a paper I found when I was looking for similar information...I did not find an answer:
BH accretion disk theory
http://arxiv.org/pdf/1104.5499v3.pdf
pg44:
Islam Hassan said:Thanx Naty, so the short answer is "we really don't know...", pity...IH
Drakkith said:Perhaps. I'd wait and see if someone else can answer your question before concluding we don't know.
The most spectacular accretion discs found in nature are those of active galactic nuclei and of quasars, which are believed to be massive black holes at the center of galaxies. As matter follows the tendex line into a black hole, the intense gravitational gradient gives rise to intense frictional heating; the accretion disc of a black hole is hot enough to emit X-rays just outside of the event horizon. The large luminosity of quasars is believed to be a result of gas being accreted by supermassive black holes. This process can convert about 10 percent of the mass of an object into energy as compared to around 0.5 percent for nuclear fusion processes.
The large luminosity of quasars is believed to be a result of gas being accreted by supermassive black holes. This process can convert about 10 percent of the mass of an object into energy as compared to around 0.5 percent for nuclear fusion processes.
Drakkith said:From wiki:http://en.wikipedia.org/wiki/Accretion_disk
Not sure what it would be for a regular black hole.
Naty1 said:That process is external to the BH horizon.
Islam Hassan said:Thanx for that reference; should have thought of it myself...so say 10% for the accretion disk radiation, perhaps a like proportion for the relativistic jet too?
IH
The concept of mass-energy in relation to black holes is based on Einstein's theory of relativity, which states that mass and energy are equivalent and can be converted into one another. In the case of black holes, the immense gravitational pull causes matter to collapse and convert into energy, which is then trapped within the black hole's event horizon.
Black holes re-radiate mass-energy through a process called Hawking radiation. This occurs when pairs of particles and antiparticles are created just outside the event horizon of a black hole. One of the particles gets pulled into the black hole, while the other escapes and radiates outwards as Hawking radiation.
Yes, the amount of mass-energy re-radiated by a black hole is directly proportional to its size. This means that larger black holes will re-radiate more mass-energy compared to smaller ones. This is because larger black holes have a stronger gravitational pull, which allows them to absorb more matter and convert it into energy.
No, we cannot observe the re-radiation of mass-energy from black holes directly. This is because the Hawking radiation is very weak and is drowned out by other sources of radiation in the universe. However, scientists have been able to indirectly observe the effects of Hawking radiation, such as the decrease in a black hole's mass over time.
The re-radiation of mass-energy through Hawking radiation gradually decreases the mass of a black hole. As the black hole loses mass, its gravitational pull also weakens, and it becomes less effective at pulling in new matter. This ultimately leads to the evaporation of the black hole, which can take trillions of years for a supermassive black hole.