The DECam Local Volume Exploration Survey: Overview and First Data Release

The DECam Local Volume Exploration survey (DELVE) is a 126-night survey program on the 4 m Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile. DELVE seeks to understand the characteristics of faint satellite galaxies and other resolved stellar substructures over a range of environments in the Local Volume. DELVE will combine new DECam observations with archival DECam data to cover ∼15,000 deg 2 of high Galactic latitude (∣ b ∣ > 10°) southern sky to a 5 σ depth of g , r , i , z ∼ 23.5 mag. In addition, DELVE will cover a region of ∼2200 deg 2 around the Magellanic Clouds to a depth of g , r , i ∼ 24.5 mag and an area of ∼135 deg 2 around four Magellanic analogs to a depth of g , i ∼ 25.5 mag. Here, we present an overview of the DELVE program and progress to date. We also summarize the first DELVE public data release (DELVE DR1), which provides point-source and automatic aperture photometry for ∼520 million astronomical sources covering ∼5000 deg 2 of the southern sky to a 5 σ point-source depth of g = 24.3 mag, r = 23.9 mag, i = 23.3 mag, and z = 22.8 mag. DELVE DR1 is publicly available via the NOIRLab Astro Data Lab science platform.