Last modified: December 2018

URL: http://cxc.harvard.edu/sherpa/ahelp/accretiondisk.html
Jump to: Description · Example · ATTRIBUTES · Notes · Bugs


AHELP for CIAO 4.11 Sherpa v1

accretiondisk

Context: models

Synopsis

A model of emission due to an accretion disk.

Syntax

accretiondisk

Description

It is for use when the independent axis is in Angstroms.


Example

>>> create_model_component("accretiondisk", "mdl")
>>> print(mdl)

Create a component of the accretiondisk model and display its default parameters. The output is:

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.ref      frozen         5000 -3.40282e+38  3.40282e+38  angstroms
   mdl.beta     thawed          0.5          -10           10           
   mdl.ampl     thawed            1 -3.40282e+38  3.40282e+38           

ATTRIBUTES

The attributes for this object are:

ref

The reference wavelength, in Angstroms.

beta

The index of the power-law component.

ampl

The amplitude of the disk.

norm

The normalization value for the position. It is a hidden parameter, with a value fixed at 20000.

Notes

The functional form of the model for points is:

f(x) = ampl * (x / norm)^(-beta) * exp(-ref / x)

and for integrated data sets the low-edge of the grid is used.


Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.