arXiv subjects

Rodrigo Cuellar

Publications and source records attributed to Rodrigo Cuellar.

3 recordsLinked to original sources

arXiv2026

The SDSS-V Local Volume Mapper (LVM): Technical Overview

The Sloan Digital Sky Survey V (SDSS-V) Local Volume Mapper (LVM) is an ultra-wide integral field spectroscopic survey of the Milky Way, the Magellanic Clouds, and a sample of galaxies in the local volume. The LVM spatially resolved spectroscopy covers the bulk of the optical range (3600-9800 A) at medium spectral-resolution (R = 2200-5500), and maps the disks of these galaxies at high physical spatial resolution (< 1 pc in the MW and ~10 pc in the Magellanic Clouds). Observations are carried out with the LVM Instrument (LVM-I), a custom-built robotic telescope, instrument, and facility located at Las Campanas Observatory (LCO) in Chile. In this article we present a technical overview of the LVM project. We describe the hardware, the survey observing strategy, and the details of how science and calibration observations are carried out. We provide a high-level overview of the survey data flow, including the reduction and calibration of the LVM spectra, and the production of the main data products that are released by the project. We also present an assessment of the LVM data quality and instrumental stability based on science observations. The main goal of this article is to serve as a primer for LVM users, providing the technical information required for the adequate analysis, modeling, and interpretation of the LVM data.

astro-ph.IM↗

arXiv2025

From the Intergalactic to the Interstellar Scales -- EQUALS: a High-resolution Legacy Survey of Gas in the Distant Universe Using ESPRESSO

Understanding how the Universe evolved from diffuse primordial gas into the rich cosmic web we observe today is one of the great challenges of modern astrophysics. Quasar absorption lines - the imprints left by intervening gas on the light from distant quasars - provide key diagnostics of many aspects of this investigation, ranging from fundamental physics to cosmology and galaxy formation. The unprecedented combination of extremely precise wavelength calibration, high spectral resolution and high sensitivity of the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) has finally enabled observations that will further constrain both state-of-the-art cosmological simulations of galaxy evolution and theoretical stellar nucleosynthetic yields. In this article, we present the ESPRESSO Quasar Absorption Line Survey (EQUALS), an ESO Large Programme, designed to tackle several outstanding questions from constraining the properties of dark matter at the smallest scales probed by the Lyman-alpha forest to determining the temperature of the intergalactic medium at z ~ 4 and precisely quantifying the chemical contributions of stellar populations in the early Universe. EQUALS will provide a legacy sample of deep spectra to showcase ESPRESSO capabilities to the quasar absorption line community whilst providing epoch measurements for the key science goals of upcoming spectroscopic instrumentation on the next generations of telescopes.

astro-ph.GA↗

arXiv2025

Quasar radiation transforms the gas in a merging companion galaxy

Quasars, powered by gas accretion onto supermassive black holes, rank among the most energetic objects of the Universe. While they are thought to be ignited by galaxy mergers and affect the surrounding gas, observational constraints on both processes remain scarce. Here we unveil a major merging system at redshift $z \approx 2.7$, and demonstrate that radiation from the quasar in one galaxy directly alters the gas properties in the other galaxy. Our findings reveal that the galaxies, with centroids separated by only a few kiloparsecs and approaching each other at speed $\approx550\,$km$\,$s$^{-1}$, are massive, form stars, and contain a substantial molecular mass. Yet, dusty molecular gas seen in absorption against the quasar nucleus is highly excited and confined within cloudlets with densities $\sim 10^5$ - $10^6$ cm$^{-3}$ and sizes $<$0.02 pc, several orders of magnitude more compact than those observed in intervening (non-quasar) environments. This is also approximately 10$^5$ times smaller than currently resolvable through molecular-line emission at high redshifts. We infer that, wherever exposed to the quasar radiation, molecular gas is disrupted, leaving behind surviving dense clouds too small to give birth to new stars. Our results not only underscore the role of major galaxy mergers in triggering quasar activity, but also reveal localized negative feedback as a profound alteration of internal gas structure which likely hampers star formation.

astro-ph.GA↗