CSST-feh 0.0.1

Two packages that can be used to estimate the metallicity of stars from the CSST filter systems

CSST_feh

The code is used to estimate the metallicity of stars from the CSST filter systems. It is worth noting that only FGK-type stars are valid.
dwarf_feh is a astronomy Python package specifically designed to estimate the metallicity of the dwarf stars from CSST filter systems.
giant_feh is a astronomy Python package specifically designed to estimate the metallicity of the giant stars from CSST filter systems.

How to install

#from PyPI (recommmend)
python3 -m pip install CSST_feh

Quick start

The input are u, g and i magnitudes and color error. The three magnitudes can be given from photometric data. An assumption that magnitudes are independent Gaussian variables is made. We recommend that the error of the magnitude should not be larger than 0.025 mag. The color error represents the combination of the error of two magnitudes.
If you want to estimate the metallicity of the dwarf stars, you should use dwarf_feh package. The output are two files named dwarf_feh_predicted.csv and dwarf_feh_error.csv, the former stores the photometric metallicity and the latter stores the random error of photometric metallicity.

from CSST_feh import dwarf_feh
dwarf_feh.dwarf_feh(u,g,i,error)

For the giant stars, you should use giant_feh package. The output are two files named giant_feh_predicted.csv and giant_feh_error.csv, the former stores the photometric metallicity and the latter stores the random error of photometric metallicity.

from CSST_feh import giant_feh
giant_feh.giant_feh(u,g,i,error)

An example

If a file (dwarf_feh.csv) is given, u, g, i magnitudes are contained in this file. Once the color error is given, you can precess the data through the command line like this.

py
import pandas as pd
data=pd.read_csv('dwarf_feh.csv')
u0=data.loc[:,['u']].values
g0=data.loc[:,['g']].values
i0=data.loc[:,['i']].values
u,g,i=u0.flatten(),g0.flatten(),i0.flatten()
# give the color error
error=(0.01**2+0.01**2)**0.5
# estimate the metallicity of the dwarf stars
from CSST_feh import dwarf_feh
dwarf_feh.dwarf_feh(u,g,i,error)

API

dwarf_feh(u,g,i,error)

Args:
    u: array-like, shape (n, )
       CSST u band
    
    g: array-like, shape (n, )
       CSST g band
       
    i: array-like, shape (n, )
       CSST i band
       
    error: float
       color error. An assumption that (u-g) and (g-i) are independent Gaussian variables is made.

giant_feh(u,g,i,error)

Args:
    u: array-like, shape (n, )
       CSST u band
    
    g: array-like, shape (n, )
       CSST g band
       
    i: array-like, shape (n, )
       CSST i band
       
    error: float
       color error. An assumption that (u-g) and (g-i) are independent Gaussian variables is made.