arXiv subjects

Catalina Morales-Gutiérrez

Publications and source records attributed to Catalina Morales-Gutiérrez.

3 recordsLinked to original sources

arXiv2026

Unveiling the dark matter nature with reionization relics

Dark matter constitutes roughly one-fourth of the Universe, yet its physical nature remains unknown. Warm dark matter (WDM), a class of dark matter candidates, has non-negligible velocity dispersion that suppresses the formation of small-scale cosmic structures. Current constraints therefore rely mainly on small-scale probes such as the Lyman-alpha (Ly$α$) forest and Milky Way observations of satellite galaxies and stellar streams. We propose a novel large-scale probe based on long-lived "reionization relics": because the thermal and dynamical evolution of the intergalactic medium depends on the local reionization redshift, patchy reionization imprints additional large-scale fluctuations in Ly$α$ forest opacity and post-reionization HI traced by 21 cm intensity mapping. The strength of these imprints depends on WDM through both small-scale gas evolution and WDM-driven changes in the reionization history. For example, the Ly$α$ (21 cm) power spectrum in 3 keV WDM differs from cold dark matter by ~19% (~19%) at $k=0.05\,{\rm Mpc^{-1}}$ at z=4 (z=5.5) when reionization relics are included. Using Ly$α$ forest with a covariance model designed to mimic the capabilities of the Dark Energy Spectroscopic Instrument (DESI), we forecast a constraint of $m_{\rm WDM}>5.0\,{\rm keV}$ (95%), which improves to $m_{\rm WDM}>7.1\,{\rm keV}$ when combined with 21 cm intensity-mapping observations from the Square Kilometre Array (SKA). The next-generation surveys can further strengthen the current best lower bounds from 9.7 to 39 keV.

astro-ph.CO↗

arXiv2024

Reionization relics in the cross-correlation between the Ly$α$ forest and 21 cm intensity mapping in the post-reionization era

The tumultuous effects of ultraviolet photons that source cosmic reionization, the subsequent compression and shock-heating of low-density regions, and the modulation of baryons in shallow potential wells induced by the passage of ionization fronts, collectively introduce perturbations to the evolution of the intergalactic medium in the post-reionization era. These enduring fluctuations persist deep into the post-reionization era, casting a challenge upon precision cosmology endeavors targeting tracers in this cosmic era. Simultaneously, these relics from reionization also present a unique opportunity to glean insights into the astrophysics that govern the epoch of reionization. In this work, we propose a first study of the cross-correlation of \lya forest and 21 cm intensity mapping, accounting for the repercussions of inhomogeneous reionization in the post-reionization era. We investigate the ability of SKA $\times$ DESI-like, SKA $\times$ MUST-like, and PUMA $\times$ MUST-like instrumental setups to achieve a high signal-to-noise ratio (SNR) in the redshift range $3.5 \leq z \leq 4$. Moreover, we assess how alterations in integration time, survey area, and reionization scenarios impact the SNR. Furthermore, we forecast the cross-correlation's potential to constrain cosmological parameters under varying assumptions: considering or disregarding reionization relics, marginalizing over reionization astrophysics, and assuming perfect knowledge of reionization. Notably, our findings underscore the remarkable capability of a futuristic PUMA $\times$ MUST-like setup, with a modest 100-hour integration time over a 100 sq. deg. survey, to constrain the ionization efficiency error to $σ_ζ= 3.42 $.

astro-ph.CO↗

arXiv2023

Impact of inhomogeneous reionization on post-reionization 21 cm intensity mapping measurement of cosmological parameters

21 cm intensity mapping (IM) has the potential to be a strong and unique probe of cosmology from redshift of order unity to redshift potentially as high as 30. For post-reionization 21 cm observations, the signal is modulated by the thermal and dynamical reaction of gas in the galaxies to the passage of ionization fronts during the Epoch of Reionization. In this work, we investigate the impact of inhomogeneous reionization on the post-reionization 21 cm power spectrum and the induced shifts of cosmological parameters at redshifts $3.5 \lesssim z \lesssim 5.5$. We make use of hydrodynamics simulations that could resolve small-scale baryonic structure evolution to quantify HI abundance fluctuation, while semi-numerical large box 21cmFAST simulations capable of displaying inhomogeneous reionization process are deployed to track the inhomogeneous evolution of reionization bubbles. We discussed the prospects of capturing this effect in two post-reionization 21 cm intensity mapping experiments: SKA1-LOW and PUMA. We find the inhomogeneous reionization effect could impact the HI power spectrum up to tens of percent level and shift cosmological parameters estimation from sub-percent to tens percent in the observation of future post-reionization 21 cm intensity mapping experiments such as PUMA, while SKA1-LOW is likely to miss this effect at the redshifts of interest given the considered configuration. In particular, the shift is up to 0.0206 in the spectral index $n_s$ and 0.0192 eV in the sum of the neutrino masses $\sum m_ν$ depending on the reionization model and the observational parameters. We discuss strategies to mitigate and separate these biases.

astro-ph.CO↗