2025 Joint ARGOS-TITAN-TOSCA workshop

Session

21 cm data analysis

8 juil. 2025, 14:30

Room Stelios Orphanoudakis (FORTH Central Building)

25. Learnlet for component separation of noisy data

Dr Victor Bonjean (FORTH)

08/07/2025 14:30

Blind source separation (BSS) plays a pivotal role in modern astrophysics by enabling the extraction of scientifically meaningful signals from multi-frequency observations. Traditional BSS methods, such as those relying on fixed wavelet dictionaries, enforce sparsity during component separation, but may fall short when faced with the inherent complexity of real astrophysical signals. In this...

26. Foreground cleaning strategies for HI 21 cm signal extraction

Dr Sia Gkogkou (FORTH)

08/07/2025 14:55

Neutral hydrogen (HI) intensity mapping is a powerful probe of cosmological parameters, the epoch of reionization, and the dark ages. However, extracting the HI signal is challenging due to astrophysical foregrounds that are over four orders of magnitude stronger. This work evaluates various blind source separation and fitting methods for reconstructing the HI signal under different telescope...

27. Higher order statistics for HI intensity mapping

Pauline Gorbatchev

08/07/2025 15:20

HI intensity mapping is a promising tool for probing large-scale structure, but at late times the 21cm signal becomes strongly non-Gaussian due to nonlinear gravitational evolution and astrophysical effects. Standard two-point statistics like the angular power spectrum fail to capture this non-Gaussian information, potentially limiting their ability to constrain cosmological parameters. We...