A Y-band look of the sky with 1-m class telescopes

TL;DR

This study demonstrates the effectiveness of 1-meter class telescopes equipped with Y-band filters for extragalactic observations, including galaxy counts, brown dwarfs, and high-redshift quasars, highlighting Y-band's potential in small telescope astronomy.

Contribution

It provides the first constraints on Y-band galaxy and star counts using small telescopes and validates the i-z-Y color-color diagram for high-redshift quasar selection.

Findings

Y-band galaxy and star counts constrained at bright end.

i-z-Y diagram effectively identifies z > 6 quasars.

Small telescopes can successfully conduct Y-band extragalactic studies.

Abstract

Y -band is a broad passband that is centered at ~ 1 micron. It is becoming a new, popular window for extragalactic study especially for observation of red objects thanks to recent CCD technology developments. In order to better understand the general characteristics of objects in Y -band, and to investigate the promise of Y -band observations with small telescopes, we carried out imaging observation of several extragalactic fields, brown dwarfs and high redshift quasars with Y -band filter at the Mt. Lemmon Optical Astronomy Observatory and the Maidanak observatory. From our observations, we constrain the bright end of the galaxy and the stellar number counts in Y -band. Also, we test the usefulness of high redshift quasar (z > 6) selection via i-z-Y color-color diagram, to demonstrate that the i-z-Y color-color diagram is effective for the selection of high redshift quasars even with a conventional optical CCD camera installed at a 1-m class telescope.