SPHINX: Solving the riddles from stellar populations in UVX galaxies
I'm delighted to announce that the SPHINX project has been awarded the Fondecyt Fellowship, securing three years of fully funded research! Ranked number 2 among the 29 projects submitted in Astronomy & Astrophysics, and honoured among only 12 awarded, this recognition highlights the impact and potential of our work. Starting in April 2024, I will be joining the EvolGal4D group led by Prof. Patricia Tissera at the Pontificia Universidad Católica de Chile in Santiago, Chile, to delve into some of the most intriguing questions in current Astrophysics.
SPHINX, which stands for Stellar Populations Hid IN uvX, is dedicated to exploring the causes of the UV upturn phenomenon in galaxies or other aged stellar systems.
The origin of our Universe finds its roots in the well-established theory of the "Big Bang." Currently, our Universe is an intriguing blend, with 30% comprised of matter and an astonishing 70% shrouded in mysterious dark energy. Of the 30% matter, a mere 4% is what we term "baryonic" - visible components like stars, galaxies, gas, and dust. The remaining 96% consists of "dark matter" and "dark energy" combined. Our investigations predominantly focus on this discernible 4%, as direct detection methods are limited to this fraction.
Galaxies and galaxy clusters emerge as the fundamental building blocks of the visible Universe. Among their observable constituents, stars stand out as arguably the most vital. The study of these stellar objects unravels a myriad of details – from their formation and evolution to masses, ages, luminosities, and chemical compositions.
Yet, peering into galaxies beyond our own - the Milky Way - presents a formidable challenge. Observing a galaxy involves capturing the collective light of all its stars, akin to gazing at a dense forest without discerning individual leaves, only seeing a vast expanse of greenery. The information about stars within a galaxy is, in essence, encrypted, demanding numerous assumptions to decipher. An invaluable ally in this cosmic decryption process is our detailed knowledge of the Milky Way. Through intricate analysis of its tenant stars, we construct what we term "stellar population libraries," essential tools in our pursuit of unravelling the mysteries of the Cosmos.
In the context of the Stellar Populations Hid IN uvX (SPHINX) Project, our focus is on delving into one of the most intriguing cosmic puzzles found in galaxies hosting aged stars. Typically, ultraviolet light is associated with the fiery brilliance of young, hot stars. Therefore, one would anticipate a vibrant ultraviolet glow in galaxies with recent star formation. However, our perplexity arises from the detection of robust ultraviolet light in galaxies inhabited by old and cold stars – a phenomenon aptly named the "ultraviolet upturn" or simply "UVX," where the "X" signifies an unexpected excess.
This UVX mystery becomes even more compelling when we realize that similar phenomena occur within aged stellar clusters within our very own Milky Way. Most notably observed in Globular Clusters, but intriguingly also detected in old Open Clusters, this phenomenon occurs right in our cosmic neighborhood. It's akin to witnessing a celestial enigma unfolding not just in the distant reaches of the cosmos but surprisingly close to home.
The SPHINX project unfolds a variety of paths for investigating the UV upturn phenomenon. Possibilities range from testing stellar population libraries to thoroughly exploring globular clusters. A key aspect involves a detailed and systematic comparison of observational features with simulations, offering a nuanced understanding of cosmic intricacies. Alongside these, the project considers various other potential avenues for exploration.
This well-rounded approach positions SPHINX as a pragmatic initiative, poised to uncover insights through a range of explorations. The project's adaptability reflects its commitment to methodical investigations.
Stay tuned for upcoming news on the SPHINX project!
If you're interested or keen on collaboration, we welcome your involvement. Feel free to get in touch!