.. _example_datasets_plot_sdss_line_ratios:


SDSS Line-ratio Diagrams
------------------------
This shows how to plot line-ratio diagrams for the SDSS spectra.  These
diagrams are often called BPT plots [1]_, Osterbrock diagrams [2]_,
or Kewley diagrams [3]_. The location of the dividing line is taken from
from Kewley et al 2001.

References
~~~~~~~~~~
.. [1] Baldwin, J. A.; Phillips, M. M.; Terlevich, R. (1981)
       http://adsabs.harvard.edu/abs/1981PASP...93....5B
.. [2] Osterbrock, D. E.; De Robertis, M. M. (1985)
       http://adsabs.harvard.edu/abs/1985PASP...97.1129O
.. [3] Kewley, L. J. `et al.` (2001)
       http://adsabs.harvard.edu/abs/2001ApJ...556..121K



.. image:: ../images/datasets/plot_sdss_line_ratios_1.png
    :scale: 100
    :align: center


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