Institut d'Estudis Espacials de Catalunya

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...

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...

Red novae, their progenitors, and remnants

Abstract Red novae or luminous red novae are a class of optical transients that have emerged over the past two decades. They occupy an intermediate-luminosity regime between classical novae and supernovae and are characterized by cool, slowly expanding ejecta and a pronounced evo...

Integrated positioning and communication via LEO satellites: A contemporary overview

Low Earth orbit (LEO) satellites, as a prominent technology in the sixth generation non-terrestrial network, offer both positioning and communication capabilities. While these two applications have each been extensively studied and have achieved substantial progress in recent yea...

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...

SN 2024iss: A Multiwavelength Exposé of a Type IIb Supernova with an Early-time Ultraviolet Spectrum and Shock-breakout Constraints

Abstract We present multiwavelength observations and analysis of SN 2024iss, a Type IIb supernova (SN IIb) located at ∼14 Mpc. The first Zwicky Transient Facility detection of SN 2024iss is ∼40 minutes after first light (one of the earliest detections of a SN IIb to date) and a H...

Analysis of Tonga eruption-induced disturbances in the upper thermosphere based on atmospheric drag accelerations from LEO satellites

Abstract The violent eruption of the Tonga volcano on 15 January 2022 triggered significant disturbances in the atmosphere and ionosphere. However, limited observational capabilities have persistently hindered the characterization of eruption-induced neutral density disturbances...

Gas absorption of soft X-rays strongly impacts the redshift distribution of dark Fast X-ray Transients

Abstract The progenitors of many Fast X-ray Transients (FXTs) and those of γ-ray bursts (GRBs) are strongly linked. Given that ”dark” GRBs are typically found to be events suffering from enhanced extinction in the host galaxy, we investigate the nature of ”dark” FXTs. However, un...

The efficient star-forming regions of stripped-envelope supernovae

Abstract Massive stars ($\ge 8\, \rm {M}_{\odot }$) play a key role in shaping the interstellar medium of galaxies through stellar feedback. However, how these stars form and evolve before exploding as core-collapse supernovae (SNe) remains elusive. We compute for the first time...

ODIN: Confirmation and 3D Reconstruction of Six Massive Protoclusters at Cosmic Noon

Abstract Protoclusters represent sites of accelerated galaxy formation and extreme astrophysical activity characteristic of dense environments. Identifying massive protoclusters and mapping their spatial structures are therefore crucial for understanding how large-scale environme...

GRB 260310A / SN 2026fgk: A Multi-Wavelength Study of a Nearby Underluminous Long GRB and SN with a Complex Afterglow

Abstract We present a comprehensive multi-wavelength study of GRB 260310A / SN 2026fgk, a nearby (z = 0.153), long-duration gamma-ray burst (GRB) with an exceptionally underluminous prompt γ-ray emission and a Comptonized spectrum. The burst occurred at the edge of a blue host ga...

Measuring masses of transiting Earth-like planets: first insights from the PLATO RV Data Challenge

Abstract The PLATO Stellar Variability Mitigation Working Group designed a radial-velocity (RV) data challenge to assess the precision and accuracy achievable on RV semi-amplitudes in the context of the future PLATO follow-up. Using Sun-as-a-star observations obtained with HARPS-...

Decentralized GNSS at global scale via graph-aware diffusion adaptation

Abstract Network-based Global Navigation Satellite Systems (GNSS) support critical infrastructure and autonomous systems, but centralized processing hubs limit scalability, resilience, and latency. We present a global-scale decentralized GNSS architecture that jointly estimates r...