radiant

RADIAl velocity from liNe profiles simulaTor

(wild acronym by ACRONYM)

Simulate radial velocity observations of a star using phase-dependent line profile variations and simulated planets.

The simulation uses Keplerian parameters of a planet and LSD profiles to produce a set of observations -- Doppler-shifted LSD profiles, each having 100 points and centered at 5500Å. To simulate instrumental noise, Gaussian noise is added to the LSD profiles (signal-to-noise ratio of 10⁴ introduces spread of approximately 1 m s^-1 in radial velocity). The observations between the availbale profiles are interpolated.

Example

The radial velocity obervations simulated using the provided input.config example provided:

The periodogram of the generated dataset, containing two major peaks - rotation of the star and the planet's orbital period:

Requirements

• Python 3+
• numpy
• scipy
• PyAstronomy
• matplotlib
• progressbar (optional)

Usage

Set the values in input.config, such as the star's mass and rotation period, planet's mass and orbital parameters, input files with the line profiles (.s1 files), plotting and output paths and settings. The example is provided and should be used as a template, comments start with # symbol. To run the simulation, run $ python main.py in the directory.

The example .s1 files contain 100 line profiles each, for different phases of the rotation of the star, based on ZDI observations of ε Eridani with added magnetic spots. See details in Lisogorskyi et al. 2020.