Skip to main content

Home/ Oxford astro-ph Coffee/ Group items tagged black holes

Rss Feed Group items tagged

Phil Marshall

An origin of the radio jet in M87 at the location of the central black hole - 0 views

  •  
    Hada et al reckon they can position the black hole to +/- 20 microarcsec, and resolve jet emission 100 Schwarzschild radii away!
Tessa Baker

Cosmic Censorship: Formation of a Shielding Horizon Around a Fragile Horizon - 0 views

  •  
    The Cosmic Censorship hypothesis suggests that gravitational singularities will always be hidden from the view of an external observer by an event horizon. It's sometimes given the status of a 'fundamental principle of the universe', though there's no particularly solid reasoning behind this (as far as I'm aware, at least). This short paper explores a gedanken experiment that attempts to violate cosmic censorship.
Phil Marshall

[1110.0854] The UV peak in Active Galactic Nuclei : a false continuum from blurred refl... - 0 views

  •  
    Andy Lawrence suggests that the unaccounted for UV flux in AGN spectra could be coming from "clouds" of gas orbiting the black hole at ~10 Schwarzschild radii, and reflecting light as UV line emission which all gets blurred together to make a broad continuum due to the insane speeds involved.
  •  
    I saw Andy yesterday at the Edinburgh sims workshop - he agreed that his clouds were probably shreds, but all that really matters is the filling factor and ionisation state, and the code he used to play around with it all is called "cloudy"... I told him we found the model pretty plausible (stuff comes off accretion disks and stays in orbit, absorbing and emitting, fine), his hope is that someone makes a more detailed model, checks his results and does some inference. That'll be Lance then...
1 - 3 of 3
Showing 20 items per page