GALFIT-CORSAIR: implementing the core-Sersic model into GALFIT

TL;DR

GALFIT-CORSAIR is a new software tool that extends GALFIT to include the core-Sersic model, enabling more accurate 2D analysis of galaxy cores and improving understanding of galaxy structure.

Contribution

It introduces the first implementation of the core-Sersic model into GALFIT, facilitating detailed 2D galaxy core analysis with better constraints.

Findings

Successfully fits core-Sersic galaxies in 2D

Reproduces previous 1D analysis results

Provides improved constraints on galaxy core properties

Abstract

We introduce GALFIT-CORSAIR: a publicly available, fully retro-compatible modification of the 2D fitting software GALFIT (v.3) which adds an implementation of the core-Sersic model. We demonstrate the software by fitting the images of NGC 5557 and NGC 5813, which have been previously identified as core-Sersic galaxies by their 1D radial light profiles. These two examples are representative of different dust obscuration conditions, and of bulge/disk decomposition. To perform the analysis, we obtained deep Hubble Legacy Archive (HLA) mosaics in the F555W filter (~V-band). We successfully reproduce the results of the previous 1D analysis, modulo the intrinsic differences between the 1D and the 2D fitting procedures. The code and the analysis procedure described here have been developed for the first coherent 2D analysis of a sample of core-Sersic galaxies, which will be presented in a forth-coming paper. As the 2D analysis provides better constraining on multi-component fitting, and is fully seeing-corrected, it will yield complementary constraints on the missing mass in depleted galaxy cores.