PACCE: Perl Algorithm to Compute Continuum and Equivalent Widths

TL;DR

PACCE is a Perl-based tool that automates the measurement of continuum levels and equivalent widths in stellar spectra, providing accurate results and uncertainty estimates, facilitating stellar population analysis.

Contribution

It introduces a new Perl algorithm for automated continuum and equivalent width measurements, with validation against manual methods and added uncertainty computation.

Findings

Equivalent widths are consistent with manual measurements within 0.2A for SSP models.

Good correlation in real stellar spectra with differences up to 0.5A.

Provides mean continuum and line center continuum useful for stellar studies.

Abstract

We present Perl Algorithm to Compute continuum and Equivalent Widths (pacce). We describe the methods used in the computations and the requirements for its usage. We compare the measurements made with pacce and "manual" ones made using iraf splot task. These tests show that for SSP models the equivalent widths strengths are very similar (differences <0.2A) for both measurements. In real stellar spectra, the correlation between both values is still very good, but with differences of up to 0.5A. pacce is also able to determine mean continuum and continuum at line center values, which are helpful in stellar population studies. In addition, it is also able to compute the uncertainties in the equivalent widths using photon statistics. The code is made available for the community through the web at http://www.if.ufrgs.br/~riffel/software.html.