Martin Elvis: Quasar Spectral Energy Distributions: Twisted Tori

April 1, 2014
Martin Elvis: Quasar Spectral Energy Distributions: Twisted Tori

For a long time we have known that our view of the centers of quasars is often blocked by optically thick dusty material - the “obscuring torus”. But to block a large solid angle requires a large height/radius ratio which is hard to achieve with cold matter. Andy Lawrence and I proposed that a thin torus that is twisted through large angles is a natural solution. I am investigating the spectral energy distributions (SEDs) of quasars in SDSS adding near-IR UKIDSS and mid-IR WISE data to see if the predictions of our model hold up.

The Three Forms of Radiation Pressure and the Structure of Quasars:

Quasars have a big picture theory: a supermassive black hole surrounded by an accretion disk with a relativistic jet emerging in the radio-loud minority. But this model explains only what it was designed to explain; it makes no predictions for most of what we see in quasar spectra - the abundance of emission and absorption lines. I have a phenomenological model for the structure of quasars that explained all of them with a funnel shaped accretion disk wind. We now have the start of a physical model using line driving (as in O-star winds). We are extending this model and investigating its detailed predictions, to see if this appealingly elegant explanation of so much observational detail works really works.

Contact

Martin Elvis: melvis@cfa

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