eniric/corrections.py
"""
Table 3 from Artigau et al. (2018):
Multiplicative correction factors to be applied
on the RV precision derived from stellar models.
These values correspond to the square-root of
the flux-weighted mean Q ratio between observation
and models for each bandpass. The nominal values are
for a comparison with the default model described here,
but we also explore the impact of other physical parameter
choices.
+---------+--------+-----+-----+-----+-----+
| |Nominal | Variants |
+=========+========+=====+=====+=====+=====+
|[Fe/H] |−0.5 |0.0 | | | |
+---------+--------+-----+-----+-----+-----+
|logg |5.0 | |5.5 | | |
+---------+--------+-----+-----+-----+-----+
|Teff (K) |3200 | | |3400 |3000 |
+---------+--------+-----+-----+-----+-----+
|g |0.66 |0.63 |0.69 |0.82 |0.51 |
+---------+--------+-----+-----+-----+-----+
|r |0.82 |0.76 |0.84 |1.08 |0.60 |
+---------+--------+-----+-----+-----+-----+
|i |0.94 |0.81 |0.99 |1.26 |0.73 |
+---------+--------+-----+-----+-----+-----+
|z |1.27 |1.09 |1.20 |1.82 |0.96 |
+---------+--------+-----+-----+-----+-----+
|Y |0.29 |0.30 |0.27 |0.30 |0.25 |
+---------+--------+-----+-----+-----+-----+
|J |0.38 |0.40 |0.31 |0.54 |0.37 |
+---------+--------+-----+-----+-----+-----+
|H |1.37 |0.95 |1.82 |1.42 |1.23 |
+---------+--------+-----+-----+-----+-----+
|K |1.47 |1.06 |2.00 |1.66 |1.27 |
+---------+--------+-----+-----+-----+-----+
"""
from typing import Dict
def correct_artigau_2018(band: str) -> float:
"""Apply Artigau et al. (2018) Table 3 nominal Barnard's Star corrections.
Parameters
----------
band: str
Wavelength band.
Returns
-------
correction: float
Correction value to multiply synthetic model precisions by to get to "real" values.
Warning
-------
Returns the corrections from the nominal (second) column only.
"""
corrections: Dict[str, float] = {
"g": 0.66,
"r": 0.82,
"i": 0.94,
"Z": 1.27,
"z": 1.27,
"Y": 0.29,
"J": 0.38,
"H": 1.37,
"K": 1.47,
}
try:
return corrections[band]
except KeyError:
raise KeyError("Band '{}' does not have a valid correction key".format(band))