https://hdl.handle.net/10481/28285 Fri, 17 Apr 2026 07:19:56 GMT 2026-04-17T07:19:56Z https://hdl.handle.net/10481/112705 Electron densities and filling factors of extragalactic H II regions: NGC 2403 and NGC 628 Zurita Muñoz, Almudena; Bresolin, Fabio; Florido Navio, Estrella; Verley, Simon; Relaño Pastor, Mónica; Beckman, John E. Measurements of the electron density of populations of extragalactic H II regions in nearby galaxies remain limited, despite the relevance of this quantity for characterizing the porosity of the interstellar medium and the escape of the ionizing radiation. We initiated a project aimed at analysing the root-mean-square electron density , the in situ density and the volume filling factor of extragalactic H II regions, investigating the dependence of these attributes on nebular and host galaxy properties. We present an image-segmentation methodology for constructing homogeneous H II region catalogues, and apply it to two pilot galaxies: NGC 2403 and NGC 628. We derive from their Halpha luminosities and equivalent radii, and obtain and for spectroscopic subsamples. While is below 300 cm^-3⁠, is typically one to two orders of magnitude lower, implying that the filling factor is in the range 0.0001 to 0.1⁠. The two galaxies exhibit a similar size–density relation⁠, which breaks for  equivalent radius >~ 50 pc, show at most a weak dependence of on galactocentric radius for NGC 2403, and no clear dependence of or on these parameters. Combining these results with published data, presents tentative scaling relations with the median H II region size, the fraction of large regions in the parent galaxy, and the star formation rate surface density. These trends, if confirmed, would provide new constraints for massive cluster formation models and important clues for interpreting dependencies observed at high redshift, underscoring the necessity of consistently extending this analysis to larger samples. We acknowledge support from project PID2023-150178NB-I00 (and PID2020- 114414GB-I00), financed by the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU) and the Agencia Estatal de Investigación (AEI) MCIU/AEI/10.13039/501100011033, and by the European Regional Development Fund (ERDF/FEDER), UE. We also acknowledge support via grant FQM108, financed by the Junta de Andalucía (Spain). SV and EF acknowledge support from project PID2023-149578NB-I00 financed by MCIU/AEI/10.13039/501100011033, and by ERDF/FEDER, UE. AZ is grateful for the kind hospitality received at the Institute for Astronomy at the University of Hawaii in Manoa, Honolulu. FB thanksthe Departamento de Física Teórica y del Cosmos, Universidad de Granada, for the warm hospitality. Based on observations collected at the Centro Astronómico Hispano en Andalucía (CAHA) at Calar Alto, operated jointly by Junta de Andalucía and Consejo Superior de Investigaciones Científicas (IAA-CSIC). The WHT operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. This research made use of astropy, a community-developed core python (http://www.python.org) package for Astronomy (Astropy Collaboration 2013, 2018, 2022); ipython (F. Pérez & B. E. Granger 2007); matplotlib (J. D. Hunter 2007); numpy (C. R. Harris et al. 2020); scipy (P. Virtanen et al. 2020); and topcat (M. B. Taylor 2005). Funding for open access charge: Universidad de Granada / CBUA. https://hdl.handle.net/10481/112705 https://hdl.handle.net/10481/112641 Running couplings in high-temperature effective field theory Rodríguez Chala, Mikael; Dashko, Andrii; Guedes, Guilherme In this work, we study the renormalization-group evolution of parameters in the three-dimensional effective field theory (3D EFT) that describes the thermally driven electroweak phase transition of the Higgs field. We consider tree-level and radiatively generated barriers induced by beyond the Standard Model physics, enabling a first-order phase transition at and below the soft scale, respectively. For each case, we compute the two-loop running of the 3D EFT couplings, including the effects of the leading nonrenormalizable terms. We then analyze how the new contributions to the beta functions compare with those in the super-renormalizable case, highlighting their impact on perturbative computations of the scalar potential, which describes the vacuum structure of the theory. By incorporating higher-order corrections in the mass parameter evolution, as well as the running of other effective operators, we set the stage for testing their impact on phase transition dynamics in lattice simulations. https://hdl.handle.net/10481/112641 https://hdl.handle.net/10481/112349 Potential blind directions at TeraZ Rodríguez Chala, Mikael; Criado, Juan Carlos The next generation of high-luminosity electron-positron colliders, such as the electron-positron Future Circular Collider and the Circular Electron-Positron Collider operating at the Z pole (TeraZ), is expected to deliver unprecedented precision in electroweak measurements. These precision observables are typically interpreted within the Standard Model effective field theory (SMEFT), offering a powerful tool to constrain new physics. However, the large number of independent SMEFT operators allows for the possibility of blind directions, parameter combinations to which electroweak precision data are largely insensitive. In this work, we demonstrate that such blind directions are not merely an artifact of agnostic effective field theory scans, but arise generically in realistic ultraviolet completions involving multiple heavy fields. We identify several concrete multifield extensions of the Standard Model whose low-energy SMEFT projections align with known blind subspaces, and show that these persist even after accounting for renormalization group evolution and finite one-loop matching effects. Our analysis shows that TeraZ will set a new benchmark in precision for indirect searches, but fully probing the space of possible ultraviolet physics requires going beyond this stage. Later electron-positron Future Circular Collider runs at higher center-of-mass energies, together with the hadron-hadron Future Circular Collider, will provide the necessary complementary probes, enabling a far more complete exploration of the SMEFT parameter space. https://hdl.handle.net/10481/112349 https://hdl.handle.net/10481/111900 High resolution seismic imaging of an active fault in the eastern Guadalquivir Basin (Betic Cordillera, Southern Spain) Serrano Bermejo, Inmaculada; Torcal, Federico; Martín, José Benito We calculated the high resolution seismic velocity, Poisson's ratio, crack density and saturation ratio structures in and around the source areas of the Torreperogil seismic series (October 2012–April 2013). This seismic series, characterized by a large number of low magnitude (below Mw 3.7 or Md 3.9) and very shallow microearthquakes, took place in the Guadalquivir Basin, a large flexural foreland basin with a linear ENE–WSW trending bounded to the north by the Iberian Massif and to the south by the Betic Cordillera and filled from a middle Miocene to Plio–Quaternary sedimentary sequence. In the upper layers of the crust, strong low-velocity anomalies are extensively distributed under the central zone, which together with high Poisson's ratio and crack density values may correspond to rocks which are less likely to fracture, perhaps due to the accumulation of tectonic and seismic stress. 93% of the earthquakes occurred at depths of up to 8 km, which could indicate that the base of the seismogenic zone lies at this depth. The seismic series was concentrated in layers of strong structural heterogeneities (in the boundary area between low and high anomalies), which were likely to generate earthquakes due to differential strain accumulation beneath the region. The high velocity areas are also considered to be strong yet brittle parts of the fault zone, which may generate earthquakes (at depths of between 5 km and 9 km). By contrast, low velocity areas are less prone to fracture, allowing seismic slippage to take place (from 2 to 4 km depth). The best estimate of the depth of the main shock (mbLg 3.9) is 7.6 km, which could tend to nucleate at the base of the seismogenic zone, at the “fault end” on the boundary between a low velocity zone to the east and a high velocity zone to the west, indicating the fault plane which separates both areas laterally. Assuming that this seismic contrast is one of the main Torreperogil faults it could imply that stress has accumulated in an existing fault zone with lateral heterogeneity in velocity. This work has been supported by the Comisión Interministerial de Ciencia y Tecnología CICYT (Spain) projects with references CGL2012-31472 (Estructura cortical y litosférica en el Sector Central de la Cordillera Bética y su transicion al Macizo Varisco. Sismotectónica del sur-sureste de la Península Ibérica), CGL2013-46368-P (Localización de la deformación en convergencia oblicua y cuencas tardiorogénicas: estudio multidisciplinar de casos (Béticas) y modelización); Proyectos de Excelencia de la Junta de Andalucía (Spain) P09-RNM-5100 (Estructura 3D del Arco de Gibraltar y modelado numérico de la propagación de ondas sísmicas de terremotos en la zona de contacto de placa Nubia-Eurasia) and RNM-451 (Evolución reciente de los contactos principales entre dominios estructurales/reológicos del Sistema del Arco de Gibraltar: estudios integrados tierra-mar); and Grupo de Investigación de la Junta de Andalucía (Spain) RNM-104, Sismología y Geofísica. https://hdl.handle.net/10481/111900 https://hdl.handle.net/10481/111898 Distribution of crack density parameter in Central Betic Cordillera (Southern Spain) Serrano Bermejo, Inmaculada; Torcal, Federico; Morales Soto, José Abstract In this study we have used high-resolution P- and S-wave velocity results to estimate crack density (ε, epsilon) and saturation ratio (ξ, xi) at a depth of 2 km in an intramountain basin and surrounding regions. Detailed observations of gravity, seismic profile and geological data reveal high ε consistent with large sedimentary thickness and minimum ε coinciding with elevations arising from the basement of the basin. From the distribution of seismic measurements of ξ it is possible to identify the presence of aquifers in detrital sediments, sandstone and dolostone. However, ξ does not show significant changes for the aquifers in geological formations made up also of schists and marbles. A low ξ anomaly in the western part could be associated with Triassic evaporite and clay rocks, and high values of ξ in the southwestern part near thermal springs may be imaging the intricate system of fractures which connect at depth with aquifer rocks. This work has been supported by the Comisión Interministerial de Ciencia y Tecnología CICYT (Spain) projects with references CGL2012–31472 (Estructura cortical y litosférica en el Sector Central de la Cordillera Bética y su transicion al Macizo Varisco. Sismotectónica del sur-sureste de la Península Ibérica), CGL2009–11384 (Transpresión y reparto de la deformación en la rama norte del Arco de Gibraltar (25 m.a. -Reciente): registro estructural, evolución tectónica y modelización); Proyectos de Excelencia de la Junta de Andalucía (Spain) P09-RNM-5100 (Estructura 3D del Arco de Gibraltar y modelado numérico de la propagación de ondas sísmicas de terremotos en la zona de contacto de placa Nubia-Eurasia) and P08-RNM-03713 (Dinámica del Sistema del Arco de Gibraltar: Estudios geológicos multidisciplinares tierra-mar y evolución 4D); and Grupo de Investigación de la Junta de Andalucía (Spain) RNM-104, Sismología y Geofísica. https://hdl.handle.net/10481/111898