PROFIT: a new alternative for emission-line PROfile FITting

TL;DR

The paper introduces PROFIT, a new IDL routine for fitting emission-line profiles with Gaussian or Gauss-Hermite series, improving analysis of gas kinematics in astrophysical objects from data cubes.

Contribution

PROFIT offers a novel, user-friendly alternative for emission-line profile fitting, demonstrated with application to Seyfert galaxy spectra, showing better fits with Gauss-Hermite series.

Findings

Gauss-Hermite series better fit emission-line profiles than Gaussian curves.

High h_3 values indicate biconical outflows near the radio structure.

Radio jet influences gas kinematics, with partial obscuration by the galaxy disc.

Abstract

I briefly describe a simple routine for emission-line profiles fitting by Gaussian curves or Gauss-Hermite series. The PROFIT (line-PROfile FITting) routine represent a new alternative for use in fits data cubes, as those from Integral Field Spectroscopy or Fabry-Perot Interferometry, and may be useful to better study the emission-line flux distributions and gas kinematics in distinct astrophysical objects, such as the central regions of galaxies and star forming regions. The PROFIT routine is written in IDL language and is available at http://www.ufsm.br/rogemar/software.html. The PROFIT routine was used to fit the [Fe II]1.257um emission-line profiles for about 1800 spectra of the inner 350 pc of the Seyfert galaxy Mrk1066 obtained with Gemini NIFS and shows that the line profiles are better reproduced by Gauss-Hermite series than by the commonly used Gaussian curves. The two-dimensional map of the h_3 Gauss-Hermite moment shows its highest absolute values in regions close to the edge of the radio structure. These high values may be originated in an biconical outflowing gas associated with the radio jet - previously observed in the optical [O III] emission. The analysis of this kinematic component indicates that the radio jet leaves the center of the galaxy with the north-west side slightly oriented towards us and the south-east side away from us, being partially hidden by the disc of the galaxy.