Joan Alcaide-Núñez

During my 5-week research stay at the Osservatorio Astronomico di Brera, I worked on multi-messenger cosmology using Gamma-Ray Burst (GRB) data and simulated Binary Neutron Star (BNS) merger populations to constrain cosmological parameters.

The aim of the project was in understanding how the combination of these two independent information sources could provide tigher constraints on the Hubble constant and other cosmological parameters, contributing to the resolution of the Hubble tension.

For the analysis of GRBs, I used the E_peak - E_iso relation (Amati Relation), whcih I computed for each combination of cosmological parameters (O_m - O_Lambda) and fitted using the chi squared test to find the prefered cosmological settings. On the other end, I got data from BNS simulations from Colombo et al. 2025 and used those data to create a Hubble diagram (z - d_L) and infer the best-fit parameters that way.

Future work includes using short GRB data associated with the BNS simulation instead of using separate long GRB data for the cosmological constraints. Moreover, one could explore the effect of sensitivity and observation rate of events with new observatories, such as the Einstein Telescope (ET), to forecast what precision levels can we achieve with specific number of detections.

I would like to thank my advisors Dr. Giancarlo Ghirlanda, Dr. Om Sharan Salafia and Dr. Alberto Colombo for their invaluable guidance and the opportunity in first place to conduct a research stay at the Osservatorio Astronomico di Brera.

As Principal Investigator of the CAPIBARA (Collaboration for the Analysis of Photonic and Ionic Bursts and Radiation) Collaboration, I lead a team of student researchers in developing open-source tools with the aim to explore the high energy cosmos.

Project Goals:

• Build a cosmic ray detector (scintillator detector) to be deployed into space within an educational payload hosting satellite with OBA FARADAY and PLD Space's SPARK program.
• Create an organisation of young students with similar interests: astrophysics, engineering, etc and foster collaboration and intellectual exchange.
• In a long-term view, to launch a dedicated CubeSat mission (mid 2030s) for the monitoring of high-energy trasient events and gravitational wave counterparts.
• Showcase the capabilities of students in high-end research.

Visit the project's website for more information.

During my research stay at ICE-CSIC-IEEC, I worked on measuring cosmological distances using Type Ia Supernovae as standard candles, contributing to the ongoing effort to resolve the Hubble tension.

Research Methodology:

• Analysis of photometric data from various surveys
• Light curve fitting using SALT2 model
• Used measured distances to recompute the Hubble constant and other parameters

Key Results:

• Computed Hubble constant within the accepted uncertainty limits
• Learned about the research process and daily life at a research institute
• Deveoped mathematical and programing skills

During my 2-week internship at the German Space Agency's Institute for Remote Sensing, I gained hands-on experience with satellite data analysis and remote sensing techniques.

• Internship Experience: 2-week internship at the Institute for Remote Sensing (IMF-DLR) as Price at Jugend Forscht Landeswettbewerb.
• Departmental Work: First week with Experimental Methods Department (hyperspectral imaging, SVC spectrometers, field measurements, drone-boat testing). Second week with Photogrammetry and Image Processing Department (data analysis using QGIS and GDAL, satellite data analysis, thermal imaging).
• Additional Activities: Visited the German Space Operations Centre (GSOC) and the DLR plane hangar.

My early research project focused on using Cepheid variable stars as standard candles for cosmological distance measurements, laying the foundation for my future work in cosmology.

Research Approach:

• Analysis of Cepheid light curves from the Konkoly Observatory Extragalactic Cepheid Database
• Period-luminosity relation application (Leavitt Law)
• Distance measurements to nearby galaxies
• Computed Hubble constant value compatible with latest professional measurements

Significance:

• Provided foundation for understanding distance ladder methods
• Developed skills in astronomical data analysis
• Inspired continued interest in cosmological research

Currently pursuing a Bachelor of Science in Physics at one of Germany's leading universities, with a focus on astrophysics.

Completed dual diploma program with outstanding academic achievement, graduating with perfect grades in Abitur (1.0/1.0) and Bachillerato, equivalent to 4.0/4.0 GPA

Final Thesis: Recomputations of the Hubble-Lemaître Constant with Distance Ladder Methods in the Context of the current Crisis in Cosmology (translated from: "Neuberechnungen der Hubble-Lemaître-Konstante mit Distance-Ladder Methoden in Betrachtung der aktuelle Krise der Kosmologie")

Academic Excellence:

• Perfect score in Abitur (1.0/1.0)
• Top-of-class graduation
• DPG Abiturpreis for outstanding physics performance
• Multiple Jugend Forscht awards
• Languages: German, Spanish, English, Catalan

Comprehensive status report detailing the achievements, challenges, and future directions of the CAPIBARA Collaboration after its first year of operation.

Key Sections:

• Project overview and objectives
• Technical implementation details
• Team structure and contributions
• Milestones achieved in Year 1
• Future roadmap and development plans

Impact:

• Established foundation for continued collaboration
• Documented best practices and lessons learned
• Provided template for future student-led research initiatives

Comprehensive final examination project focusing on independent recomputation of the Hubble-Lemaître constant using various distance ladder methods and comparison with modern measurements.

Methodology:

• Analysis of Cepheid variable star data
• Type Ia Supernovae light curve fitting
• Calibration of period-luminosity relations
• Statistical error analysis

Key Findings:

• Independent verification of Hubble tension
• Assessment of systematic uncertainties
• Comparison with Planck and SH0ES results

Educational resource developed for high school students, providing an accessible introduction to astrophysics concepts and research methods.

Content Coverage:

• Basic astronomical concepts and terminology
• Introduction to cosmological principles
• Overview of research methods in astrophysics
• Career paths in astronomy and physics

Educational Impact:

• Used as teaching material in high school physics classes
• Inspired interest in astrophysics among younger students
• Provided foundation for further independent study

Early research project conducted as part of the Youth and Science Program, focusing on understanding and replicating Hubble constant measurements using publicly available data.

Project Scope:

• Introduction to cosmological distance measurements
• Basic data analysis techniques
• Understanding of measurement uncertainties
• Comparison with established values

Learning Outcomes:

• Foundation in cosmological research methods
• Experience with scientific computing
• Understanding of current challenges in cosmology

Educational presentation developed for elementary school students, introducing basic concepts of space exploration and astronomy in an engaging, accessible manner.

Educational Approach:

• Age-appropriate explanations of space concepts
• Interactive elements and visual aids
• Focus on inspiring curiosity about space
• Connection to current space missions

Impact:

• Successfully delivered to multiple elementary school classes
• Positive feedback from students and teachers
• Contributed to early science education outreach