SHELS: A Complete Galaxy Redshift Survey with R$\leq$20.6

TL;DR

The SHELS survey provides a dense, complete redshift catalog of galaxies up to R=20.6 in two fields, enabling detailed studies of galaxy structure, evolution, and properties at intermediate redshifts.

Contribution

This paper presents the first complete, high-density redshift survey of a 4 deg$^2$ field to R=20.6, including new measurements of redshift, spectral indices, stellar mass, and metallicity for over 16,000 galaxies.

Findings

The survey is 95% complete to R=20.6.

The median redshift of the sample is 0.3.

The data reveal clear evolutionary trends in galaxy properties.

Abstract

The SHELS (Smithsonian Hectospec Lensing Survey) is a complete redshift survey covering two well-separated fields (F1 and F2) of the Deep Lens Survey to a limiting R = 20.6. Here we describe the redshift survey of the F2 field (R.A.$_{2000}$ = 09$^h$19$^m$32.4$^s$ and Decl.$_{2000}$ = +30$^{\circ}$00$^{\prime}$00$^{\prime\prime}$). The survey includes 16,294 new redshifts measured with the Hectospec on the MMT. The resulting survey of the 4 deg$^2$ F2 field is 95\% complete to R = 20.6, currently the densest survey to this magnitude limit. The median survey redshift is $ z = 0.3$; the survey provides a view of structure in the range 0.1 $ \lesssim z \lesssim 0.6$. A movie displays the large-scale structure in the survey region. We provide a redshift, spectral index D$_n$4000, and stellar mass for each galaxy in the survey. We also provide a metallicity for each galaxy in the range 0.2 $< z <0. 38$. To demonstrate potential applications of the survey, we examine the behavior of the index D$_n$4000 as a function of galaxy luminosity, stellar mass, and redshift. The known evolutionary and stellar mass dependent properties of the galaxy population are cleanly evident in the data. We also show that the mass-metallicity relation previously determined from these data is robust to the analysis approach.