# The merger remnant NGC 3610 and its globular cluster system: a large-scale study

## TL;DR

This study provides a detailed large-scale analysis of NGC 3610 and its globular cluster system, revealing bimodal color distributions, a low number of GCs, and structural features consistent with a recent merger.

## Contribution

It offers the first large-scale, detailed photometric analysis of NGC 3610's GC system and galaxy structure, extending previous research with new imaging data.

## Key findings

- Detection of bimodal GC color distribution at intermediate radii
- The GC system is relatively poor with about 500 members
- Galaxy exhibits structural features like boxy isophotes and fine-structure

## Abstract

We present a photometric study of the prototype merger remnant NGC 3610 and its globular cluster (GC) system, based on new GEMINI/GMOS and ACS/HST archival images. Thanks to the large FOV of our GMOS data, larger than previous studies, we are able to detect a `classical' bimodal GC colour distribution, corresponding to metal-poor and metal-rich GCs, at intermediate radii and a small subsample of likely young clusters of intermediate colours, mainly located in the outskirts. The extent of the whole GC system is settled as about 40 kpc. The GC population is quite poor, about 500 +/- 110 members, that corresponds to a low total specific frequency S_N ~ 0.8. The effective radii of a cluster sample are determined, including those of two spectroscopically confirmed young and metal-rich clusters, that are in the limit between GC and UCD sizes and brightness. The large-scale galaxy surface-brightness profile can be decomposed as an inner embedded disc and an outer spheroid, determining for both larger extents than earlier research (10 kpc and 30 kpc, respectively). We detect boxy isophotes, expected in merger remnants, and show a wealth of fine-structure in the surface-brightness distribution with unprecedented detail, coincident with the outer spheroid. The lack of symmetry in the galaxy colour map adds a new piece of evidence to the recent merger scenario of NGC 3610.