ENIRIC - Extended Near InfraRed Information Content

Eniric is a Python 3 software to compute the theoretical Radial Velocity (RV) precision of stellar spectra. Eniric is an overhaul and extension to the code used in Figueria et al. 2016 to analysis the precision of M-dwarf stars. Extending the performance and usability, it is able to be used on any synthetic spectra from the PHOENIX-ACES and BT-Settl (CIFIST2001-2015) libraries.

Checkout the documentation on Read the Docs!

Features:

Eniric contains a number of features to transform and prepare the spectra (observed and synthetic).

• Spectral broadening

  Allows for Rotational and Instrumental broadening of synthetic spectra given a rotation speed vsini and resolution R.

• Atmospheric transmission masking

  Analyzing the RV precision attainable under the different masking conditions presented in Figueira et al. 2016_.

  The three conditions specifically treated are:

  • No contamination or treatment of atmospheric transmission
  • Masking all regions affected by atmospheric absorption of a given depth % over the course of the year.
  • Assuming perfect telluric correction in which the variance of the measured flux is impacted.

• Relative RV precision

  The RV precision can be calculated relative to a specified SNR per pixel in the center of a spectroscopic band. The default as used in the Figueira et al. 2016 is a SNR of 100 at the center of the J-band.

• Spectral Resampling

  Allows for resampling of synthetic spectra to N pixels per FWHM.

• SNR normalization.

  Normalize spectral flux to a defined SNR level.

• Band selection

  Analysis splitable into individual photometric bands Z\ , Y\ , J\ , H\ , K. User definable.

• Theoretical RV precision

  Compute spectral RV precision and spectral quality.

• Incremental quality & precision

  Determine the RV precision and spectral quality on narrow wavelength slices across the entire spectrum, similar to that present in Figure 1 of Artigau et al. 2018 <http://adsabs.harvard.edu/abs/2018AJ....155..198A>_.

• Analyse relative precision of synthetic libraries

  The RV precision of are present relative to a specified SNR per pixel in the center of a photometric band. The default as used in Figueira et al. 2016_ is a SNR of 100 at the center of the J-band.

  • Available through [Starfish]'s() grid_tools.
    • PHOENIX-ACES
    • BT-Settl

Contents

• Installation
• Configuration
• Basic Usage
• Broadening
• Atmospheric Transmission
• Normalization
• Resampling
• Theoretical Precision of Synthetic Spectra
• Scripts
• Example Notebooks
• Utilities

Background

The origin of this code was used in Figueira et al. 2016.

P. Figueira, V. Zh. Adibekyan, M. Oshagh, J. J. Neal, B. Rojas-Ayala, C. Lovis, C. Melo, F. Pepe, N. C. Santos, M. Tsantaki, 2016,
Radial velocity information content of M dwarf spectra in the near-infrared,
Astronomy and Astrophysics, 586, A101

It had a number of efficiency issues with convolution which were improved upon

To reproduce the updated results for Figueira et al. 2016 run

phoenix_precision.py -t 3900 3500 2800 2600 -l 4.5 -m 0.5 -r 60000 80000 100000 -v 1.0 5.0 10.0 -b Z Y J H K

after installation and configuration.