Browsing by Author "Tissera, Patricia"
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- ItemBaryon effects on void statistics in the EAGLE simulation(2017) Paillas Villavicencio, Enrique; Lagos, Claudia D. P.; Padilla, Nelson; Tissera, Patricia
- ItemCharacterisation of compact stellar systems in the Coma cluster of galaxies(2021) Ángel Ángel, Simón Andrés; Puzia, Thomas H.; Tissera, Patricia; Goudfrooij, Paul; Pontificia Universidad Católica de Chile. Instituto de AstrofísicaWe present the Coma Cluster Core PrOject (C3PO), a deep, high resolution and contiguous mosaic survey of the inner ⇡ 150 square arcminutes of the core of the Coma Cluster. The region was tiled by 21 HST/WFC3 pointings and was observed in F336W from the UVIS channel, and F160W from the IR channel. Using this data, and combining this with archival data in F475W and F814W taken previously in programs led by some of our team members, we study the compact stellar systems of said cluster. We separate those systems from background galaxies and foreground stars guided by a nearUV/visible/near-IR colour-colour diagram, obtaining more than 9000 objects. From our selection, we study the globular cluster luminosity function in our available bands, finding values of the turn-over magnitude of 26.2 mag for F814W, 27.3 mag for F475W, and 25.8 in F160W. We recover the blue and red GC populations found by Peng et al. [138], finding similar relative abundances and spatial distribution. We do not recover the colour distribution found by Madrid et al. [119] because their extremely red objects are not present in our data, most likely due to the inclusion of the u band. For the first time with such diagnostic power, age and metallicity are derived for distant GCs. 60% of our GC sample falls inside the range of our SSP models, finding an age-metallicity relation that does not correlate with any single colour, but is rather dependant on pairs of colours. The age and metallicity also do not correlate strongly with spatial distribution or environment. Colour-colour relations with visible (gi) colours show differences with varying environment, which may indicate differences in star formation history and chemical enrichment history. The dataset also contains a large number of UCDs, and the method can be easily expanded to also find NSCs.
- ItemCharacterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane(2017) Minniti, D.; Dekany, Istvan; Majaess, Daniel; Palma, Tali; Pullen, Joyce; Rejkuba, Marina; Alonso-García, Javier; Catelan, Márcio; Hempel, Maren; Zoccali, Manuela; Contreras Ramos, Rodrigo Andrés; Gonzalez, Oscar A.; Irwin, Mike; Lucas, Philip W.; Saito, Roberto K.; Tissera, Patricia; Valenti, Elena
- ItemModelling of resolved scaling relations in simulated galaxies(2023) Cornejo Cárdenas, Anell; Tissera, Patricia; Pontificia Universidad Católica de Chile. Instituto de AstrofísicaWe developed a new numerical tool, called SpecGSG (i.e. Spectra Generator of Simulated Galaxies), which aims to generate synthetic spectra of simulated galaxies in order to improve comparisons between simulations and observations. Through this code we can obtain spatially resolved spectral information that considers the contribution of stellar populations and the nebular emission produced by gas close to young stellar populations. A fundamental aspect of this tool, and what differentiates it from other previous works (e.g., Nanni et al. 2022), is that the nebular emission is calculated based on the properties of the gas surrounding recently born stellar populations. This code allowed us to study both the intrinsic properties of the simulations and the properties we derived from their synthetic spectra. From the intrinsic properties of the simulations we found an anti-correlation between the ionization parameter and gas metallicity. Additionally, we used SpecGSG to recover spatially resolved scaling relations using the synthetic spectra generated from the simulated galaxies in local regions. In particular, we focused on two scaling relations: (1) the spatially resolved star-forming main sequence (rSFMS), i.e. the relationship between the Star Formation Rate surface density (ΣSFR) and the stellar mass surface density (Σ∗), and (2) the spatially resolved mass-metallicity relation (rMZR), i.e. the relationship between the gas-phase metallicity and Σ∗. From these synthetic spectra, we found that the metallicity has a first dependence on Σ∗ and a second dependence on ΣSFR. This agrees with results obtained in observations of galaxies. Therefore, SpecGSG allows us to calculate the properties of the simulations from a more observational way, improving comparisons between observational and simulation data. At the moment, SpecGSG only implements a simple model of dust that downgrades the spectra due to its presence in the star-forming regions. The treatment of dust attenuation and re-emission along the line of sight between each emitting source and the observer, will be implemented in a future work.
- ItemThe central spheroids of milky way mass-sized galaxies(2018) Tissera, Patricia; Machado, Rubens E.; Carollo, Daniela; Minniti, D.; Beers, Timothy C.; Zoccali, Manuela; Meza, Andres
- ItemThe stellar metallicity gradients in galaxy discs in a cosmological scenario(2016) Tissera, Patricia; Machado, Rubens E. G.; Sánchez Blazquez, Patricia; Pedrosa, Susana E.; Sánchez, Sebastián F.; Snaith, Owain N.; Vilchez, José N.