Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Origin of Wavelength-Dependent Continuum Delays in AGNs - a New
  Model   A model of wavelength-dependent lags in optical continuum variability of AGNs
is proposed which avoids the problems of the popular ``lamp-post'' model.
Rather than being due to reprocessing of high-energy radiation from a
hypothetical source above the accretion disk, the wavelength-dependent delays
observed from the B to I bands are instead due to contamination of an
intrinsically coherently variable continuum with the Wien tail of the thermal
emission from the hot dust in the surrounding torus. The new model correctly
gives the size, wavelength dependence, and luminosity dependence of the lags,
and quantitatively predicts observed color hysteresis. The model also explains
how the measured delays vary with epoch of observation. There must also be
contamination by scattered light and this can be detected by a lag in the
polarized flux.

16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex