Projects

Low-mass main-sequence stars lose angular momentum over time, leading to a decrease in their magnetic activity. The details of this rotation-activity relation remain poorly understood, however. Using observations of members of the 300 Myr-old open cluster Group-X, we aim to characterize the rotation-activity relation at this age. We will measure the equivalent width of the H-alpha line—which serves as an indicator of magnetic chromospheric activity—from mid-resolution optical spectra of several dozen cluster members. We will convert equivalent width into H-alpha luminosity, which we will then compare against rotational data for the same stars. our chromospheric activity-rotation relation analysis will make Group-X a critical new benchmark as we seek to map out the behavior of low-mass stars over their first 1 Gyr.)

Extragalactic mapping is the main tool that allows us to study the nature of the Universe, trying to answer a multitude of questions such as the nature of dark matter, dark energy and the initial conditions of the Universe. These mappings observe maps of the distribution of galaxies or supernovae during different phases of the history of the Universe with instruments at different frequencies, such as optical or radio. In this way we can try to study uninvestigated epochs such as the "redshift desert". One of the main tests of gravity theory on cosmological scales is the study of the growth rate of large-scale structures. This growth rate produces distortions in the redshifts of galaxies due to the peculiar velocities of the galaxies by the local gravitational field. The proposed project consists of measuring this effect on the angular distribution of extragalactic mapping galaxies through the angular correlation function and the possible use of tomography. The project will learn how to handle and visualize data catalogs, measure correlation functions and determine cosmological parameters through comparison with cosmological theory. Cosmological simulations will also be used to validate the measurement codes.

With the data coming from the successful Gaia mission, it has been possible to study in unprecedented detail the complicated formation process of the Milky Way. We now know that about nine billion years ago the last major collision with the progenitor of the so-called "Gaia Sausage" occurred (Belokurov et al., 2018; Helmi et al., 2018). Recent studies (e.g., Aguado et al., 2021; Matsuno et al., 2021) have pointed out a significant enrichment of elements produced via fast neutron absorption or r-process. The observed Eu abundance and Ba/Eu ratios open the door to an extended study to understand the formation of these elements in galaxies smaller than the Milky Way (e.g., Ji et al., 2016). This project relies on high-resolution data from the FIES spectrograph at the Nordic Telescope (NOT), at the Roque de los Muchachos Observatory in the Canary Islands. The student will participate in the analysis and derive heavy element abundances that allow understanding the phenomenon in the lower metallicity (less chemically evolved) limit.

The development of increasingly sensitive radio telescopes has been accompanied by an increase in the number of molecules detected in the interstellar medium. The synthesis of these molecules is a hotly debated topic within the astrochemical community, although there is a consensus on the importance of dust grains in the chemical pathways forming these molecules. However, at the temperature characteristic of molecular clouds (10 K, -263°C), regions of the interstellar medium particularly suitable for the formation of complex molecules, the thermal energy is insufficient for an effective release of the newly synthesized molecules into the gas, where they are detected. One of the most popular hypotheses to circumvent this problem consists in explaining the return of the molecules to the gas using the energy produced in the chemical reaction of formation itself, a process known as "Chemical Desorption". In this work, you will use kinetic simulations to determine the fraction of chemical desorption needed to account for the abundances of such important molecules in space chemistry as methanol (CH3OH), acetaldehyde (CH3CHO) or acetonitrile (CH3CN). To carry out this project, a computer with a Linux operating system or, failing that, a fully functional alternative, e.g. Linux Subsystem for Windows installed and properly configured, is required.

Space weather is influenced by solar eruptive phenomena such as CMEs and flares. They can impact and affect the Earth’s magnetosphere. The relationship between clusters of fast Coronal Mass Ejections (CMEs) (v > 1000 km/s) and their potential geoeffectiveness by evaluating the geomagnetic Dst index was widely explored by Rodríguez Gómez et al. 2020 during solar cycles 23 and 24. The clusters were defined as fast CMEs that occur in close succession. In the current project, the potential geoeffectiveness of solar flares during solar cycles 23, 24 and the ascending phase of solar cycle 25 will be explored.

The solar wind originates from the continuous emission of plasma from the solar corona into outer space, thus permeating the interplanetary medium. Although its existence has been well-known for decades, major problems remain to be solved. One of these enigmas is the acceleration of the wind, which sometimes reaches velocities of up to 800 km/s. One of the possible explanations is Alfvénic fluctuations, coherent variations of the magnetic field, and plasma velocity that are similar to Alfvén Waves. It is believed that these waves could provide an additional source of momentum and energy to accelerate the solar wind. This project focuses on the study of the macroscopic properties of the solar wind, as well as the characterization of Alfvénic fluctuations and their evolution in relation to the distance to the sun, time scales, and relevant plasma parameters. To carry out this analysis, in-situ observations of the solar wind taken by different space missions, such as HELIOS, WIND, and Parker Solar Probe, will be used.