The Second Data Release of the KODIAQ Survey

TL;DR

The second data release of the KODIAQ survey provides a comprehensive, high-resolution, publicly available quasar spectral dataset with 300 quasars and over 800 spectra, enabling advanced studies of ionized absorption in the universe.

Contribution

This paper introduces the second data release of the KODIAQ survey, significantly expanding the publicly available high-resolution quasar spectra dataset with 130 new quasars and additional observations.

Findings

Contains 831 spectra from 300 quasars

Total exposure time of approximately 4.9 megaseconds

Includes data from 1577 exposures in high-resolution spectra

Abstract

We present and make publicly available the second data release (DR2) of the Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ) survey. KODIAQ DR2 consists of a fully-reduced sample of 300 quasars at 0.07 < z_em < 5.29 observed with HIRES at high resolution (36,000 <= R <= 103,000). DR2 contains 831 spectra available in continuum normalized form, representing a sum total exposure time of ~4.9 megaseconds on source. These co-added spectra arise from a total of 1577 individual exposures of quasars taken from the Keck Observatory Archive (KOA) in raw form and uniformly processed. DR2 extends DR1 by adding 130 new quasars to the sample, including additional observations of QSOs in DR1. All new data in DR2 were obtained with the single-chip Tektronix TK2048 CCD configuration of HIRES in operation between 1995 and 2004. DR2 is publicly available to the community, housed as a higher level science product at the KOA and in the igmspec database (v03).