Astrophysics at the UTFSM
The recently formed Astrophysical Sciences group at UTFSM is designed to have two divisions: extragalactic and stellar astrophysics. Both divisions work observationally and theoretically on vibrant research fields. The stellar astrophysics group is focussed on planetary science, compact objects, and binary stars while the extragalactic division concentrates on cosmology, galaxy formation and evolution, large-scale structure, and the halo-galaxy connection.
Stellar Astrophysics
The Stellar Astrophysics group will work mostly on two different but related topics covering some of the most vital areas of modern astrophysics.
The discovery of the first exoplanet around a sun-like star in 1995 revolutionized modern astrophysics. Various space and ground based observing facilities have been built in the last 25 years and led to the discovery of a large variety of exoplanetary systems. With now more than 4000 discovered exoplanets, the field shifts from planet hunting planets towards characterizing the chemical composition of exoplanets and understanding their formation and evolution. As part of the Millennium Nucleus for Planet Formation (www.npf.cl), the astrophysics group at the Campus Central in Valparaíso aims at playing a major role in planetary sciences.
The second focus of our group are compact stars mostly in close binary star settings. These binaries produce some of the most energetic and fascinating events in the Universe ranging from supernovae Ia, the thermonuclear explosion of white dwarfs in close binaries, to short gamma-ray bursts which are related to the merging of two neutron stars in a close binary star configuration. At the Campus Central in Valparaíso we study the evolution of these close compact binary stars using observations performed with the arsenal of telescopes located in Chile and theoretical binary star population synthesis.
We plan to grow by hiring academics that strengthen, complement, and/or extend our current research lines.
Current research lines and some selected recent publications:
We aim at discovering and characterizing extrasolar planets and protoplanetary disks and in the near future hope to relate planet formation theories and exoplanet demographics. We also work on the dynamical evolution of planetary systems and the impact of the evolution of the host star including effects like tides and evaporation among others.
https://ui.adsabs.harvard.edu/abs/2020MNRAS.492.1531M/abstract
https://ui.adsabs.harvard.edu/abs/2020A%26A…640A..13S/abstract
https://ui.adsabs.harvard.edu/abs/2018A%26A…610A..13C/abstract
https://ui.adsabs.harvard.edu/abs/2020ApJ…898L..23R/abstract
https://ui.adsabs.harvard.edu/abs/2020MNRAS.tmp.3485L/abstract
We study magnetic field generation and evolution in white dwarfs, metal polluted white dwarfs, and planets around white dwarfs. The latter is clearly related to research line a). We also participate in large scale observational surveys of white dwarfs such as SDSS V.
https://ui.adsabs.harvard.edu/abs/2020MNRAS.497..130T/abstract
https://ui.adsabs.harvard.edu/abs/2020MNRAS.499.2564G/abstract
https://ui.adsabs.harvard.edu/abs/2019Natur.576…61G/abstract
We participate in observational surveys of close compact binary stars and perform theoretical binary population synthesis. So far we focus mostly on white dwarf binaries. We aim at a better understanding of fundamental processes such as common envelope evolution or magnetic braking.
https://ui.adsabs.harvard.edu/abs/2020MNRAS.492.1523B/abstract
https://ui.adsabs.harvard.edu/abs/2020MNRAS.491.5717B/abstract
https://ui.adsabs.harvard.edu/abs/2020MNRAS.499L.121L/abstract
Extragalactic Astrophysics
The Extragalactic Astrophysics group will address fundamental questions in the fields of cosmology, the large-scale structure of the Universe (LSS), galaxy formation and evolution, and the halo-galaxy connection. Particular emphasis will be given to projects lying in the interface between galaxy evolution and cosmology. These two fields have progressively converged into an overlapping research space in the context of next-generation cosmological surveys. Cosmology needs information about the properties of galaxies, not only for targeting and completeness purposes, but also in order to optimize the LSS mapping and the extraction of cosmological information from (LSS) multi-tracer samples. The formation and evolution of galaxies, on the other hand, cannot be disconnected from that of their hosting halos and large scale-structure, which plays a fundamental role in driving their evolution.
The extragalactic group aims at integrating multiple observational and theoretical datasets and techniques in order to shed light onto the above interconnected research fields. Among these tools : N-body numerical simulations of dark matter, hydrodynamical simulations for the baryonic component, cosmological survey data, semi-analytical models of galaxy formation and evolution and/or machine learning techniques. In terms of datasets, we are leading and also participate in several observing campaigns designed to understand the effect of environment on galaxy properties, including the large 4MOST Chilean Cluster Galaxy Evolution Survey, CHANCES which will obtain spectra for over 300.000 galaxies in and around 100 of the most massive clusters and superclusters in the low-z Universe.
We are also interested in developing new research lines, particularly related to a) machine learning applied to galaxy properties, large-scale structure, cosmology and the halo-galaxy connection, and b) gravitational waves (GW) as tracers of the LSS.
Current research lines and some selected recent publications:
This line addresses study of the Large-Scale Structure (LSS) of the Universe from theory, simulations, and observations. Particular emphasis is given to elucidating the physical origins of secondary halos bias (the secondary dependencies of halo bias on halo properties at fixed mass) and investigating the manifestation of these effects on the galaxy population (galaxy assembly bias).
https://ui.adsabs.harvard.edu/abs/2021MNRAS.500.2777T/abstract
https://ui.adsabs.harvard.edu/abs/2020arXiv200808607M/abstract
https://ui.adsabs.harvard.edu/abs/2020MNRAS.496.1182M/abstract
https://ui.adsabs.harvard.edu/abs/2019MNRAS.487.1570S/abstract
We intend to develop models that connect galaxies with halos in the context of SHAM, HOD, SAMs, or machine learning techniques.
https://ui.adsabs.harvard.edu/abs/2019MNRAS.489..653G/abstract
https://ui.adsabs.harvard.edu/abs/2019MNRAS.486.1316S/abstract
https://ui.adsabs.harvard.edu/abs/2017ApJ…839..121T/abstract
This line will be devoted to the determination of the statistical properties of the galaxy population from massive galaxy surveys. Hydrodynamical simulations such as Illustris will be used to interpret observational results.
https://ui.adsabs.harvard.edu/abs/2020arXiv201100014R/abstract
https://ui.adsabs.harvard.edu/abs/2018MNRAS.480.1415F/abstract
https://ui.adsabs.harvard.edu/abs/2016MNRAS.456.3265M/abstract
https://ui.adsabs.harvard.edu/abs/2016MNRAS.461.1131M/abstract
This line will be devoted to the development of methods that can optimize the extraction of cosmological information from surveys such as J-PAS or, particularly, the LSST.
https://ui.adsabs.harvard.edu/abs/2020MNRAS.493.5257M/abstract
https://ui.adsabs.harvard.edu/abs/2013AJ….145…10D/abstract
https://ui.adsabs.harvard.edu/abs/2012MNRAS.425..415S/abstract
This is a new research line where we will explore the potential of GW sources as LSS tracers for cosmological studies.
https://ui.adsabs.harvard.edu/abs/2020MNRAS.491.3419A/abstract
https://ui.adsabs.harvard.edu/abs/2019MNRAS.487.1675A/abstract
