IFU Spectroscopy of the Stellar Disk Truncation Region of NGC 6155

TL;DR

This study uses integral field spectroscopy to analyze the stellar populations in the outer regions of NGC 6155, revealing age increases beyond the disk truncation, supporting stellar migration theories.

Contribution

It introduces a modified spectral fitting routine for complex stellar populations and applies it to spatially resolved data of NGC 6155's disk.

Findings

Stellar ages increase beyond the surface brightness profile break.

Outer disk regions are populated through stellar migration.

Spectroscopy reaches faint surface brightness levels (~24 mag/arcsec^2).

Abstract

Like the majority of spiral galaxies, NGC 6155 exhibits an exponential surface brightness profile that steepens significantly at large radii. Using the VIRUS-P IFU spectrograph, we have gathered spatially resolved spectra of the system. Modifying the GANDALF spectral fitting routine for use on the complex stellar populations found in spirals, we find that the average stellar ages increase significantly beyond the profile break radius. This result is in good agreement with recent simulations that predict the outskirts of disk galaxies are populated through stellar migration. With the ability to bin multiple fibers, we are able to measure stellar population ages down to mu_V~24 mag/sq arcsec.