Title: Beyond Black Holes: How Data Mining and HPC Revolutionized the ULX Paradigm

Place: Seminar del DAA. Jeroni Muñoz Research Building, fourth floor, in Burjassot.

Day: Wednesday, April 9, 2025. Time: 12:00.

Abstract:

Making use of advanced Big Data management and High-Performance Computing (HPC), we have explored vast high-energy data archives, employing innovative methodologies of timing analysis to extract concealed insights within the extensive high-energy astrophysical data archives (mainly XMM-Newton, Chandra and NuSTAR). This synergistic application of Data Mining and HPC techniques has led to the discovery of a previously unrecognized cohort of Extragalactic Neutron Stars (NS). Significantly, our findings challenged the long-standing paradigm, suggesting that the predominant source of energy for Ultra-Luminous X-Ray sources (ULXs) is derived from accretion onto stellar-mass or intermediate-mass black holes — a paradigm that had persisted for over 25 years.
This paradigm shift, triggered by the identification of Pulsating ULXs (PULXs) — Neutron Stars with markedly Super-Eddington luminosities — marks a radical transformation in our comprehension of the ULX population and enhances our understanding of accretion processes. Currently, our focus revolves around a new approach that integrates HPC capabilities with newly acquired and archive X-ray observations. This approach aims to expand the PULX population as part of the "OBIWAN" project, ushering in a new era of exploration and discovery in the hot field of ULXs.