Edge-on galaxies in the Hubble Ultra Deep Field

TL;DR

This study analyzes the structure of 58 edge-on spiral galaxies at redshift around 1 in the Hubble Ultra Deep Field, revealing that their disks are relatively thicker compared to nearby galaxies, with stable vertical scales over time.

Contribution

It provides the first detailed measurements of the brightness distribution scales in distant edge-on galaxies, highlighting differences in disk thickness compared to local galaxies.

Findings

Distant galaxy disks are relatively thicker than those of nearby galaxies.

Vertical scale height remains stable at redshift z ≤ 1.

Discussion on potential evolution of radial scale length with redshift.

Abstract

We studied a sample of 58 edge-on spiral galaxies at redshifts $z \sim 1$ selected in the Hubble Ultra Deep Field. For all galaxies we analyzed the 2D brightness distributions in the $V_{606}$ and $i_{775}$ filters and measured the radial ($h_r$) and vertical ($h_z$) exponential scales of the brightness distribution. We obtained evidence that the relative thickness of the disks of distant galaxies, i.e., the ratio of the vertical scale height and radial scale length ($h_z/h_r$), on average, exceeds the relative thickness of the disks of nearby spiral galaxies. The vertical scale height $h_z$ of the stellar disks of galaxies shows no big changes at $z \leq 1$. The possibility of the evolution of the radial scale length $h_r$ for the brightness distribution with redshift is discussed.