# aesop¶

aesop is a data reduction toolkit for echelle spectra from the Astrophysical Research Consortium (ARC) 3.5 m Telescope Echelle Spectrograph (ARCES) at Apache Point Observatory (APO). You can view the source code and submit issues via GitHub.

Contents:

## What is aesop?¶

In the interest of reproducing established results, we choose not to re-implement the canonical IRAF reduction routine ReduceARCES.cl, and to limit aesop’s functionality to processing after the aperture extraction and initial wavelength solution.

The current version of aesop is useful for the following tasks:

• Managing and manipulating spectra with convenient data structures (EchelleSpectrum, Spectrum1D)
• Removing radial velocities from echelle orders via cross-correlation with PHOENIX model spectra
• Normalizing out the blaze-function in each echelle order given observations of a spectroscopic standard
• Further normalizing each order for a flat continuum with robust least-squares
• Concatenating the spectra in each order, and taking the mean between adjacent orders where they overlap, to produce a 1D spectrum from 3000-10000 Angstroms

## Typical Workflow¶

In general, aesop users will follow this procedure:

1. Install aesop
2. Run the ReduceARCES.cl IRAF script to reduce your echelle spectra (see IRAF)
3. Open the extracted 1D spectra for each spectral order with aesop (see Getting started)