Arjun T. Dey

The Composite Spectrum of QSO Absorption Line Systems in DESI DR2

Abstract We present details regarding a composite spectrum of quasar (QSO) absorption line systems. In this composite spectrum, we identify more than 70 absorption lines and observe oxygen and hydrogen emission features at a higher signal-to-noise ratio than any previous study. A...

The DESI Y1 RR Lyrae Catalog. I. Empirical Modeling of the Cyclic Variation of Spectroscopic Properties and a Chemodynamical Analysis of the Outer Halo

Abstract We present the catalog of RR Lyrae stars (RRLs) observed in the first year of operations of the Dark Energy Spectroscopic Instrument (DESI) survey. This catalog contains 6240 RRLs out to ∼120 kpc from the Galactic center and over 12,000 individual epochs with homogeneous...