# Multiwavelength survey of X-ray sources in the Sculptor Dwarf Spheroidal Galaxy

## TL;DR

This study investigates the low-mass X-ray binary population in the Sculptor Dwarf Galaxy using multiwavelength observations, revealing a scarcity of bright X-ray sources and suggesting that such binaries in globular clusters are formed dynamically.

## Contribution

It provides the first deep, multiwavelength survey of X-ray sources in the Sculptor Dwarf Galaxy, classifying most sources and highlighting the lack of bright X-ray binaries in this environment.

## Key findings

- Most X-ray sources are background objects or quasars.
- Sculptor has few bright X-ray binaries above 10^34 erg/s.
- Bright X-ray binaries in globular clusters are likely formed through dynamical processes.

## Abstract

We present an unprecedented, deep study of the primordial low-mass X-ray binary population in an isolated, lower-metallicity environment. We perform followup observations of previously-identified X-ray binary candidates in the Sculptor Dwarf Galaxy by combining a second Chandra observation with Spitzer and Gemini photometry, as well as Gemini spectroscopy of selected targets. Of the original nine bright X-ray sources identified, we are able to classify all but one as quasars, active galactic nuclei, or background galaxies. We further discover four new X-ray sources in the second-epoch Chandra observation. Three of these new sources are background sources and one is a foreground flaring star. We have found that Sculptor is effectively devoid of X-ray sources above a few 1e34 erg/s. If Sculptor is able to retain primordial binaries at a similar rate to globular clusters, this implies that bright X-ray binaries observed in globular clusters in the present epoch are all formed dynamically.