Studying Large and Small Scale Environments of Ultraviolet Luminous Galaxies

TL;DR

This study investigates the environments of ultraviolet luminous galaxies at redshifts 0.4 to 1.2, examining their clustering, pair formations, and potential interactions, to understand their star formation activity and relation to high-redshift galaxy analogs.

Contribution

It provides the first analysis of UVLG environments at intermediate redshifts, revealing their clustering properties, pair interactions, and potential links to high-redshift Lyman Break Galaxies.

Findings

UVLGs form close pairs with general galaxy populations

UVLGs rarely pair with luminous red galaxies

High surface brightness UVLGs resemble high-redshift LBGs in properties

Abstract

Studying the environments of 0.4<z<1.2 UV-selected galaxies, as examples of extreme star-forming galaxies (with star formation rates in the range of 3-30 M_sol/yr), we explore the relationship between high rates of star-formation, host halo mass and pair fractions. We study the large-scale and small-scale environments of local Ultraviolet Luminous Galaxies (UVLGs) by measuring angular correlation functions. We cross-correlate these systems with other galaxy samples: a volume-limited sample (ALL), a Blue Luminous Galaxy sample (BLG) and a Luminous Red Galaxy sample (LRG). We determine the UVLG comoving correlation length to be r_0=4.8(+11.6/-2.4) h^-1 Mpc at <z> =1.0, which is unable to constrain the halo mass for this sample. However, we find that UVLGs form close (separation < 30 kpc) pairs with the ALL sample, but do not frequently form pairs with LRGs. A rare subset of UVLGs, those with the highest FUV surface brightnesses, are believed to be local analogs of high redshift Lyman Break Galaxies (LBGs) and are called Lyman Break Analogs (LBAs). LBGs and LBAs share similar characteristics (i.e., color, size, surface brightness, specific star formation rates, metallicities, and dust content). Recent HST images of z~0.2 LBAs show disturbed morphologies, signs of mergers and interactions. UVLGs may be influenced by interactions with other galaxies and we discuss this result in terms of other high star-forming, merging systems.