synthesizer.line_ratios

A module holding useful line ratios (e.g. R23) and diagrams (pairs of ratios), e.g. BPT-NII.

Line ids and specifically the wavelength part here are defined using the cloudy standard, i.e. using vacuum wavelengths at <200nm and air wavelengths at >200nm.

Functions

synthesizer.line_ratios.get_bpt_kauffman03(logNII_Ha)

BPT-NII demarcations from Kauffman+2003.

Kauffman+03: https://arxiv.org/abs/astro-ph/0304239

Demarcation defined by:

log([OIII]/Hb) = 0.61 / (log([NII]/Ha) - 0.05) + 1.3

Parameters:

logNII_Ha (array) – Array of log([NII]/Halpha) values to give the SF-AGN demarcation line

Returns:

array

Corresponding log([OIII]/Hb) ratio array

synthesizer.line_ratios.get_bpt_kewley01(logNII_Ha)

BPT-NII demarcations from Kewley+2001.

Kewley+03: https://arxiv.org/abs/astro-ph/0106324

Demarcation defined by:

log([OIII]/Hb) = 0.61 / (log([NII]/Ha) - 0.47) + 1.19

Parameters:

logNII_Ha (array) – Array of log([NII]/Halpha) values to give the SF-AGN demarcation line

Returns:

array

Corresponding log([OIII]/Hb) ratio array