Detection and classification of supernovae beyond z~2 redshift with the James Webb Space Telescope

Future time-domain surveys for transient events in the near- and mid-infrared bands will significantly extend our understanding about the physics of the early Universe. In this paper we study the implications of a deep (~27 mag), long-term (~3 years), observationally inexpensive survey with the James Webb Space Telescope (JWST) within its Continuous Viewing Zone, aimed at discovering luminous supernovae beyond z~2 redshift. We explore the possibilities for detecting Superluminous Supernovae (SLSNe) as well as Type Ia supernovae at such high redshifts and estimate their expected numbers within a relatively small (~0.1 deg^2) survey area. It is found that we can expect ~10 new SLSNe and ~50 SNe Ia discovered in the 1 < z < 4 redshift range. We show that it is possible to get relatively accurate (sigma_z < 0.25) photometric redshifts for Type Ia SNe by fitting their Spectral Energy Distributions (SED), redshifted into the observed near-IR bands, with SN templates. We propose that Type Ia SNe occupy a relatively narrow range on the JWST F220W-F440W vs F150W-F356W color-color diagram between +/- 7 rest-frame days around maximum light, which could be a useful classification tool for such type of transients. We also study the possibility of extending the Hubble-diagram of Type Ia SNe beyond redshift 2 up to z~4. Such high-z SNe Ia may provide new observational constraints for their progenitor scenario.Comment: accepted for publication in Ap

Detecting Pair-Instability Supernovae at z<5 with the James Webb Space Telescope

Pair-instability supernovae (PISNe) are the ultimate cosmic lighthouses, capable of being observed at z<25 and revealing the properties of primordial stars at cosmic dawn. But it is now understood that the spectra and light curves of these events evolved with redshift as the universe became polluted with heavy elements because chemically enriched stars in this mass range typically lose most of their hydrogen envelopes and explode as bare helium cores. The light curves of such transients can be considerably dimmer in the near infrared (NIR) today than those of primordial PISNe of equal energy and progenitor mass. Here, we calculate detection rates for PISNe whose progenitors lost their outer layers to either line-driven winds or rotation at z<10, their detection limit in redshift for the James Webb Space Telescope (JWST). We find that JWST may be able to detect only Pop II (metal-poor) PISNe over the redshift range of z<4, but not their Pop III (metal-free) counterparts.Comment: Accepted for ApJ, in pres

Structure Formation with Cold + Hot Dark Matter

We report results from high-resolution particle-mesh (PM) N-body simulations of structure formation in an $\Omega=1$ cosmological model with a mixture of Cold plus Hot Dark Matter (C+HDM) having $\Omega_{\rm cold}=0.6$, $\Omega_\nu=0.3$, and $\Omega_{\rm baryon}=0.1$. We present analytic fits to the C+HDM power spectra for both cold and hot ($\nu$) components, which provide initial conditions for our nonlinear simulations. In order to sample the neutrino velocities adequately, these simulations included six times as many neutrino particles as cold particles. Our simulation boxes were 14, 50, and 200~Mpc cubes (with $H_0=50$ km s$^{-1}$ Mpc$^{-1}$); we also did comparison simulations for Cold Dark Matter (CDM) in a 50~Mpc box. C+HDM with linear bias factor $b=1.5$ is consistent both with the COBE data and with the galaxy correlations we calculate. We find the number of halos as a function of mass and redshift in our simulations; our results for both CDM and C+HDM are well fit by a Press-Schechter model. The number density of galaxy-mass halos is smaller than for CDM, especially at redshift $z>2$, but the numbers of cluster-mass halos are comparable. We also find that on galaxy scales the neutrino velocities and flatter power spectrum in C+HDM result in galaxy pairwise velocities that are in good agreement with the data, and about 30\% smaller than in CDM with the same biasing factor. On scales of several tens of Mpc, the C+HDM streaming velocities are considerably larger than CDM. Thus C+HDM looks promising as a model of structure formation.Comment: 33pp., 16+ figures not included (available by mail), SCIPP-92/5

Mainstreaming remotely sensed ecosystem functioning in ecological niche models

Part of this work was funded by the EU H2020 Project 641762 ‘ECOPOTENTIAL: Improving Future Ecosystem Benefits through Earth Observations’, from which many valuable thoughts originated. A.R. was funded by the Xunta de Galicia (post‐doctoral fellowship ED481B2016/084‐0) and currently by ‘Juan de la Cierva’ fellowship program funded by the Spanish Ministry of Science and Innovation (IJC2019‐041033‐I). J.G. was funded by the Individual Scientific Employment Stimulus Program (2017) by the Portuguese Foundation for Science and Technology (FCT CEECIND/02331/2017/CP1423/CT0012). S.A‐C was funded by the PORBIOTA ‐ Portuguese e‐Infrastructure for Information and Research on Biodiversity (POCI‐01‐0145‐FEDER‐022127) project grant and is currently supported by the 'María Zambrano' program funded by the Spanish Ministry of Universities and the EU‐NextGenerationEU fund.Biodiversity is declining globally at unprecedented rates. Ecological niche models (ENMs) are one of the most widely used toolsets to appraise global change impacts on biodiversity. Here, we identify a variety of advantages of incorporating remotely sensed ecosystem functioning attributes (EFAs) into ENMs. The development of ENMs that explicitly incorporate ecosystem functioning will allow a more holistic and integrative perspective of the habitat dynamics. The synergies between the increasingly available open-access satellite images and cloud-based platforms for planetary-scale geospatial analysis offer an unprecedented opportunity to incorporate ecosystem processes and disturbances (such as fires, insect outbreaks or droughts) that have been so far largely neglected in ecological niche characterization and modelling. The most paradigmatic example of EFAs is the application of time series of spectral vegetation indices related to primary productivity and carbon cycle. EFAs related to surface energy balance and water cycles derived from remote sensing products such as land surface temperature or soil moisture enable a fine-scale characterization of the species' niche—eventually improving the predictive performance of ENMs. All these advantages confirm that a new generation of ENMs based on such EFAs would offer great perspectives to increase our ability to monitor habitat suitability trends and population dynamics. However, despite the technical advances and increasing effort of remote sensing community to develop integrative EFAs, ENMs have yet to make full profit of the most recent developments by integrating them in ENMs. A coordinated agenda for remote sensing experts and ecological modellers will be essential over the coming years to bridge the gap between remote sensing and ecology disciplines and to take full (and timely) advantage of the fast-growing body of Earth observation data and remote sensing technologies—with special emphasis on the development and testing of new variables related to key processes driving ecosystem functioning.EU H2020 641762Individual Scientific Employment Stimulus ProgramSpanish Ministry of Universitiese‐Infrastructure for Information and Research on BiodiversityFundação para a Ciência e a TecnologiaMinisterio de Ciencia e InnovaciónFundació Catalana de Trasplantament CEECIND/02331/2017/CP1423/CT0012, POCI‐01‐0145‐FEDER‐022127Xunta de Galicia ED481B2016/084‐

Long-Term Cumulative Effects of Wildfires on Soil-Vegetation Dynamics in the “Baixa Limia–Serra do Xurés” Natural Park

Wildfires are recognized as major contributors to forest loss and soil degradation on a global scale. Understanding the cumulative effects of fire regimes on forest ecosystems and soil dynamics necessitates a deeper exploration of wildfire-vegetation-soil interactions over the long term. This study delves into the wildfire-landscape dynamics within the “Baixa Limia Serra do Xurés” Natural Park, a region prone to fires in Galicia, Spain. By analyzing available statistical and remote sensing data, we identified significant shifts in fire regimes and landscape dynamics between the periods of 2000–2010 and 2010–2020. Our findings indicate a potential extension of the fire season, reflecting the impacts of climate change. Despite improvements in firefighting capabilities, the occurrence of large fires is on the rise in the Natural Park, underscoring the need for proactive management strategies in such areas. Notably, significant fire events in 2011, 2016, 2017, and 2020 extensively affected wooded areas, constituting the majority of the burned area. Shrubs and forests emerged as particularly vulnerable, with varying degrees of burn severity influencing post-fire vegetation recovery rates. While shrublands expanded their coverage between 2000 and 2010, rocky areas with sparse vegetation showed an increase over the subsequent decade (2010–2020), indicating soil degradation and potential desertification in areas affected by recurrent and severe fires, especially within zones designated for the highest levels of protection (with fire rotation periods of less than 1 year). In conclusion, this study provides valuable insights into the impacts of wildfires, changes in land cover, and post-fire soil-vegetation dynamics, which can inform management and conservation efforts in fire-prone mountainous regions. Leveraging advanced remote sensing techniques enables the monitoring of cumulative soil degradation resulting from repeated wildfires over extended periods

Detection of Tidal Disruption Events around Direct Collapse Black Holes at High Redshifts with the James Webb Space Telescope

This is the third sequel in a series discussing the discovery of various types of extragalactic transients with the {\it James Webb Space Telescope} in a narrow-field ($\sim 0.1$ deg$^2$), moderately deep ($m_{AB} \sim 27$ mag) survey. In this part we focus on the detectability and observational characteristics of Direct Collapse Black Holes (DCBH) and Tidal Disruption Events (TDE) around them. We use existing models for DCBH accretion luminosities and spectra as well as for TDE light curves, and find that accreting DCBH seeds may be bright enough for detection up to $z \sim 7$ with JWST NIRCam imaging, TDEs of massive ($M \gtrsim 50$ Msol) stars around them can enhance the chance for discovering them as transient objects, although the rates of such events is low, a few per survey time. TDEs around non-accreting black holes of $M \sim 10^6$ Msol may also be detected at $z < 7$ redshifts in the redder NIRCam bands between 3 and 5 microns. It is also shown that accreting DCBHs appear separate from supernovae (SNe) on the NIRCam color-color plot, but TDEs from quiescent black holes fall in nearly the same color range as Superluminous Supernovae (SLSNe), which makes them more difficult to identify.Comment: 17 pages, 11 figures, ApJ in pres

The Effect of the Hall Term on the Nonlinear Evolution of the Magnetorotational Instability: I. Local Axisymmetric Simulations

The effect of the Hall term on the evolution of the magnetorotational instability (MRI) in weakly ionized accretion disks is investigated using local axisymmetric simulations. First, we show that the Hall term has important effects on the MRI when the temperature and density in the disk is below a few thousand K and between 10^13 and 10^18 cm^{-3} respectively. Such conditions can occur in the quiescent phase of dwarf nova disks, or in the inner part (inside 10 - 100 AU) of protoplanetary disks. When the Hall term is important, the properties of the MRI are dependent on the direction of the magnetic field with respect to the angular velocity vector \Omega. If the disk is threaded by a uniform vertical field oriented in the same sense as \Omega, the axisymmetric evolution of the MRI is an exponentially growing two-channel flow without saturation. When the field is oppositely directed to \Omega, however, small scale fluctuations prevent the nonlinear growth of the channel flow and the MRI evolves into MHD turbulence. These results are anticipated from the characteristics of the linear dispersion relation. In axisymmetry on a field with zero-net flux, the evolution of the MRI is independent of the size of the Hall term relative to the inductive term. The evolution in this case is determined mostly by the effect of ohmic dissipation.Comment: 31 pages, 3 tables, 12 figures, accepted for publication in ApJ, postscript version also available from http://www.astro.umd.edu/~sano/publications

La metodología interrogativa en la asignatura de Observación e innovación en el aula.

Es un estudio realizado sobre un profesor y las formas de interrogación que utiliza en sus clases para fomentar el aprendizaje autónomo en sus estudiantes

Reforma de local para tienda de ropa y showroom en A Coruña

[Resumen] En el presente TFG se realiza la reforma de un local comercial para tienda de ropa y showroom en A Coruña. La misión de la creación de esta tienda es satisfacer necesidades de las personas consumidoras de nuevas tendencias en marcas y alta calidad en prendas de vestir y complementos. Como punto de partida en todo negocio destinado a la venta de ropa debemos tener muy claro cómo queremos, o más bien, como nos interesa que nuestros clientes interactúen con nuestro espacio y nuestros productos. ¿El motivo? La mayor parte de sensaciones generadas en nuestro cliente tendrán como origen este punto. Existe un aspecto sumamente importante en el diseño interior de un espacio destinado a la moda, ese es, sin lugar a dudas, la iluminación del mismo. Como justificación de todo lo llevado a cabo en este trabajo incluyo un Plan de Negocio como convencimiento de la viabilidad de la creación de esta reforma para emprender este nuevo negocio, con el que aumentará la oferta en moda en la ciudad y oportunidades para nuevos profesionales de ese campo. El trabajo se compone de tres tomos: TOMO I: Memoria, en la que se incluye una breve introducción, memoria descriptiva y constructiva. Se justifica el cumplimiento del CTE y de otros reglamentos. Finalmente incluyo en los anejos todos los cálculos y especificaciones necesarias de las instalaciones, estructura, Plan de Control, Estudio de Gestión de Residuos y el Estudio Básico de Seguridad y Salud. TOMO II: Complementario al tomo anterior, incluyo el Pliego de Condiciones, Mediciones y Presupuesto, un breve Plan de Negocio, todas las fuentes documentales consultadas durante la creación del mismo y por último los agradecimientos a todas aquellas personas que me han apoyado. TOMO III: Se adjunta toda la documentación gráfica acorde con toda la documentación incluida en los dos tomos anteriores.[Abstract] In the present TFG is the reform of a commercial premises to store clothes and showroom in a Coruña. The creation of this store mission is to satisfy needs of persons with sumidoras of new trends in brands and high-quality apparel and accessories. As a starting point in any business aimed at selling clothes we must be very clear how we want, or rather, how we want our customers to interact with our space and our pro-ducts. the reason? most of feelings generated by our customer will have as a source here. There is an extremely important aspect in the interior design of a space devoted to fashion, that is, without a doubt, the same lighting. As justification of all carried out in this work include a plan of nebusiness as convinced of the feasibility of the creation of this reform to undertake this new business, which will increase supply at fashion in the city and opportunities for new professionals in this field. The work consists of three volumes: VOLUME I: Memory, which includes a brief introduction, descriptive and constructive memory. compliance with the CTE and other regulations is justified. Finally I include in annexes all the calculations and specifications necessary facilities, structure, control plan, waste management and the basic study of safety and health. VOLUME II: Complementary to the previous volume, included the statement of conditions, measurements and budget, a brief business plan, all documentary sources consulted during the creation of the same and, finally, thanks to all those who have supported me. VOLUME III: Attaches all the graphic documentation in accordance with the documentation included in the two previous volumes.Traballo fin de grao (UDC.EUAT). Arquitectura técnica. Curso 2013/201

The Effects of the Peak-Peak Correlation on the Peak Model of Hierarchical Clustering

In two previous papers a semi-analytical model was presented for the hierarchical clustering of halos via gravitational instability from peaks in a random Gaussian field of density fluctuations. This model is better founded than the extended Press-Schechter model, which is known to agree with numerical simulations and to make similar predictions. The specific merger rate, however, shows a significant departure at intermediate captured masses. The origin of this was suspected as being the rather crude approximation used for the density of nested peaks. Here, we seek to verify this suspicion by implementing a more accurate expression for the latter quantity which accounts for the correlation among peaks. We confirm that the inclusion of the peak-peak correlation improves the specific merger rate, while the good behavior of the remaining quantities is preserved.Comment: ApJ accepted. 15 pages, including 4 figures. Also available at ftp://pcess1.am.ub.es/pub/ApJ/effectpp.ps.g