synthesizer.abundances.abundance_scalings¶
A module containing various elemental abundance scalings.
This modules provides methods to scale various elements with metallicity instead of simply linearly.
- Example usage:
from synthesizer.abundances import abundance_scalings
# create an instance of the scaling class scaling = abundance_scalings.GalacticConcordance()
# get the Nitrogen abundance for a given metallicity nitrogen_abundance = scaling.nitrogen(0.02)
# get the Carbon abundance for a given metallicity carbon_abundance = scaling.carbon(0.02)
Classes
- class synthesizer.abundances.abundance_scalings.Dopita2006[source]¶
The Dopita (2006) model for abundance scalings.
This includes scalings for Nitrogen and Carbon.
References
Dopita, M. A., Kewley, L. J., & Heisler, C. A. 2006, ApJS, 167, 177 doi:10.1086/508261 https://ui.adsabs.harvard.edu/abs/2006ApJS..167..177D/abstract
- The scaling for Nitrogen is given by:
log10(N/H) = log10(1.1e-5 * Z + 4.9e-5 * Z^2)
- The scaling for Carbon is given by:
log10(C/H) = log10(6e-5 * Z + 2e-4 * Z^2)
where Z is the metallicity (mass fraction in metals).
The reference metallicity for the model is 0.016. The scaling for other elements is not provided in the original paper.
- ads¶
The ADS link to the paper.
- Type:
str
- doi¶
The DOI of the paper.
- Type:
str
- available_elements¶
List of available elements for scaling.
- Type:
list
- reference_metallicity¶
The reference metallicity for the model.
- Type:
float
- class synthesizer.abundances.abundance_scalings.GalacticConcordance[source]¶
The “Galactic Concordance” model from Nicholls et al. 2017.
In addition to providing a reference abundance pattern Nicholls et al. 2017 provide scalings for a large range of elements.
For most of these the scaling, relative to Oxygen, is a simple linear scaling with plataus at low and high O/H.
For Nitrogen and Carbon a more complicated scheme is used.
References
Nicholls, D. C., Dopita, M. A., & Sutherland, R. S. 2017, MNRAS, 466, 4403 doi:10.1093/mnras/stw3235 https://ui.adsabs.harvard.edu/abs/2017MNRAS.466.4403N/abstract
- The scaling for Nitrogen is given by:
log10(N/H) = log10(10^(-1.732) + 10^(O/H + 2.19))
- The scaling for Carbon is given by:
log10(C/H) = log10(10^(-0.8) + 10^(O/H + 2.72))
where O/H is the Oxygen to Hydrogen ratio.
The reference metallicity for the model is 0.015. The scaling for other elements is not provided in the original paper.
- ads¶
The ADS link to the paper.
- Type:
str
- doi¶
The DOI of the paper.
- Type:
str
- available_elements¶
List of available elements for scaling.
- Type:
list
- reference_metallicity¶
The reference metallicity for the model.
- Type:
float
- reference_abundance¶
Dictionary of reference abundances.
- Type:
dict
- scaling_parameters¶
Dictionary of scaling parameters for each element.
- Type:
dict
- carbon(metallicity)[source]¶
Calculate the Carbon abundance (C/H) for a given metallicity.
- Parameters:
metallicity (float) – The metallicity.
- Returns:
The logarithmic Carbon abundance, i.e. (C/H).
- Return type:
abundance (float)
- carbon_to_oxygen(oxygen_to_hydrogen)[source]¶
Calculate the Carbon to Oxygen abundance for a given (O/H).
- Parameters:
oxygen_to_hydrogen (float) – The log of the Oxygen to Hydrogen ratio, i.e. (O/H).
- Returns:
The logarithmic abundance relative to Oxygen.
- Return type:
carbon_to_oxygen (float)
- nitrogen(metallicity)[source]¶
Calculate the Nitrogen abundance (N/H) for a given metallicity.
- Parameters:
metallicity (float) – The metallicity.
- Returns:
The logarithmic Nitrogen abundance, i.e. (N/H).
- Return type:
abundance (float)
- nitrogen_to_oxygen(oxygen_to_hydrogen)[source]¶
Calculate the Nitrogen to Oxygen abundance for a given (O/H).
- Parameters:
oxygen_to_hydrogen (float) – The log of the Oxygen to Hydrogen ratio, i.e. (O/H).
- Returns:
The logarithmic abundance relative to Oxygen.
- Return type:
nitrogen_to_oxygen (float)