arXiv subjects

Casiana Muñoz Tuñón

Publications and source records attributed to Casiana Muñoz Tuñón.

3 recordsLinked to original sources

arXiv2026

Ionized Gas Kinematics and Star-forming Clumps in Extremely Metal-poor Galaxies

Extremely Metal Poor (XMP) galaxies are the least chemically evolved objects in the local Universe and provide important constraints on galaxy formation in low-metallicity environments. This work investigates the ionised gas kinematics and star formation properties of XMP galaxies to identify disturbed or multi-component gas motions and explore their connection with star formation. We analyse long-slit spectroscopic observations of nine XMP galaxies obtained with the Intermediate Dispersion Spectrograph on the 2.5m Isaac Newton Telescope. The study uses the H$α$ emission line to trace ionised gas and emission-line ratios to derive gas-phase metallicities. The kinematic analysis reveals that some galaxies exhibit ordered rotation, with kinematic centres not always coincident with the luminous star-forming heads. Most systems show disturbed, asymmetric, or declining velocity profiles, while localized distortions near bright star-forming heads suggest that massive clumps influence the surrounding gas dynamics. We derive dynamical masses for the dominant clumps and investigate the mass--metallicity and size--metallicity relations. The clumps exhibit low metallicities consistent with the XMP regime and comparable to those observed in low-mass dwarf galaxies. Three galaxies show counter-rotating or kinematically decoupled ionised-gas components, indicating complex gas kinematics and possible external gas acquisition. Our sample is predominantly composed of isolated systems, with metal-poor star formation concentrated in compact head regions. These properties may reflect gas accretion through mergers, interactions, or the acquisition of metal-poor gas from the intergalactic medium and cosmic filaments. Internal processes such as outflows, gas mixing, recycling, and stochastic star formation may also contribute to the observed properties.

astro-ph.GA↗

arXiv2026

Search for Faint Lone Double-Peaked H$α$ Lines as IMBH Signatures in the MUSE Deep Field

Double-peaked H$α$ emission profiles can serve as potential signatures of accreting intermediate-mass black holes (IMBHs), particularly those residing outside galactic nuclei. Such features are expected to arise from rotating disk-like structures around black holes and can be used to identify elusive IMBH candidates. \citet{Almeida2022ApJ...934..100S} reported a sample of such double-peaked H$α$ sources in the MUSE-Wide survey, interpreting them as potential signatures of wandering IMBHs after systematically excluding alternative explanations. Their method relied on constructing H$α$ maps around central galaxies and visually identifying compact emission clumps in the surrounding halo regions. In this work, we revisit the analysis using the deeper MUSE Extremely Deep Field (MXDF) data and an automated detection algorithm tailored to identify such features. However, we do not recover any candidate population in MXDF, resulting in a null detection. This outcome is nevertheless informative, as it (1) highlights the inherent challenges in detecting IMBHs, and (2) demonstrates the potential of automated approaches for future systematic searches, even though it did not yield a positive outcome in this case.

astro-ph.GA↗

arXiv2018

Precipitable water vapour forecasting: a tool for optimizing IR observations at Roque de los Muchachos Observatory

We validate the Weather Research and Forecasting (WRF) model for precipitable water vapour (PWV) forecasting as a fully operational tool for optimizing astronomical infrared (IR) observations at Roque de los Muchachos Observatory (ORM). For the model validation we used GNSS-based (Global Navigation Satellite System) data from the PWV monitor located at the ORM. We have run WRF every 24 h for near two months, with a horizon of 48 hours (hourly forecasts), from 2016 January 11 to 2016 March 4. These runs represent 1296 hourly forecast points. The validation is carried out using different approaches: performance as a function of the forecast range, time horizon accuracy, performance as a function of the PWV value, and performance of the operational WRF time series with 24- and 48-hour horizons. Excellent agreement was found between the model forecasts and observations, with R = 0.951 and R = 0.904 for the 24- and 48-h forecast time series respectively. The 48-h forecast was further improved by correcting a time lag of 2 h found in the predictions. The final errors, taking into account all the uncertainties involved, are 1.75 mm for the 24-h forecasts and 1.99 mm for 48 h. We found linear trends in both the correlation and RMSE of the residuals (measurements - forecasts) as a function of the forecast range within the horizons analysed (up to 48 h). In summary, the WRF performance is excellent and accurate, thus allowing it to be implemented as an operational tool at the ORM.

astro-ph.IM↗