NSF NOIRLab

Cosmological Constraints from Full-scale Clustering and Galaxy–Galaxy Lensing with DESI DR1

Abstract We present constraints on cosmic structure growth from the analysis of galaxy clustering and galaxy–galaxy lensing with galaxies from the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. Our analysis includes four samples drawn from the Bright Galaxy Survey (B...

Joint Modeling of GD-1 and C-19 as Old Streams

Abstract DESI observational data for the GD-1 and C-19 streams are compared to stream simulations in an evolving multihalo potential of a Milky Way–like galaxy based on a cosmological Milky Way–like simulation. The number of subhalos decreases with time, and the subhalo-stream en...

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. II. The Metallicity Dependency of Pulsational Properties, the Shape of the RR Lyrae Instability Strip, and Metal Rich RR Lyrae

Abstract RR Lyrae stars (RRLs) are valuable probes of both Milky Way assembly and stellar-evolution physics. Using a sample 6240 RRLs obtained in the first year of the Dark Energy Spectroscopic Instrument (DESI) survey, we investigate the metallicity of RRLs and its correlation w...

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...

Stellar masses of optically dark galaxies: uncertainty introduced by the attenuation law and star-formation histories

Abstract Recent studies using JWST have suggested that some high-redshift galaxies may be ultra-massive, thereby challenging standard models of early galaxy formation. We analyse the stellar masses using different modelling assumptions and in conjunction with new data of three ga...

Mapping the nuclear environments of extreme coronal line emitting galaxies

Abstract Extreme coronal line emitters (ECLEs) are a rare class of galactic nuclei exhibiting unusually strong high-ionisation forbidden emission lines, and several ECLEs have been linked to tidal disruption events (TDEs). In this work, we compile and analyse optical spectra of 3...

The abundance and radial distribution of faint and ultra-faint dwarfs in galaxy clusters

Abstract Cosmological simulations of galaxy clusters are unable to resolve dwarf galaxies due to limited numerical resolution which drives the artificial disruption of dark matter substructures. We address these limitations by combining the results of the cosmological hydrodynami...

DESI Strong Lens Foundry. IV. Spectroscopic Confirmation of DESI Lens Candidates with VLT/MUSE

Abstract We present integral field spectroscopic observations of 76 strong gravitational lens candidates identified with a residual neural network in the DESI Legacy Imaging Surveys, obtained with the Multi Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope. These o...

The Search for Life Elsewhere: Avoiding Hype and Fostering Public Understanding

The search for life beyond Earth presents unique challenges for science communication due to its interdisciplinary nature, the potential for groundbreaking discoveries, and the inherent uncertainties involved. The Lorentz Center workshop Breaking News: We Found Extraterrestrial L...