UV to IR Luminosities and Dust Attenuation Determined from ~4000 K-Selected Galaxies at 1<z<3 in the ZFOURGE Survey

TL;DR

This study constructs composite galaxy spectral energy distributions from ~4000 K-selected galaxies at redshifts 1-3, analyzing their UV to IR properties and dust attenuation to improve understanding of galaxy evolution.

Contribution

It introduces a new set of composite SEDs covering UV to IR for galaxies at 1<z<3, enabling better dust attenuation estimates from rest-frame colors.

Findings

Blue star-forming galaxies follow local IRX-β relations.

Dusty galaxies show scatter but are generally bluer than expected.

A linear relation links UVJ colors to dust attenuation.

Abstract

We build a set of composite galaxy SEDs by de-redshifting and scaling multi-wavelength photometry from galaxies in the ZFOURGE survey, covering the CDFS, COSMOS, and UDS fields. From a sample of ~4000 K_s-band selected galaxies, we define 38 composite galaxy SEDs that yield continuous low-resolution spectra (R~45) over the rest-frame range 0.1-4 um. Additionally, we include far infrared photometry from the Spitzer Space Telescope and the Herschel Space Observatory to characterize the infrared properties of our diverse set of composite SEDs. From these composite SEDs we analyze the rest-frame UVJ colors, as well as the ratio of IR to UV light (IRX) and the UV slope ($\beta$) in the IRX$-\beta$ dust relation at 1<z<3. Blue star-forming composite SEDs show IRX and $\beta$ values consistent with local relations; dusty star-forming galaxies have considerable scatter, as found for local IR bright sources, but on average appear bluer than expected for their IR fluxes. We measure a tight linear relation between rest-frame UVJ colors and dust attenuation for star-forming composites, providing a direct method for estimating dust content from either (U-V) or (V-J) rest-frame colors for star-forming galaxies at intermediate redshifts.