Coffee talks
Monday 21/09/2026 @ 11:30, Sala riunioni quarto piano e on-line (meet.google.com/sue-bwvk-axf)
Marco Di Bello (University of Bologna), "Study of the Molecular Gas in the Galaxy Cluster Abell 2495 via ALMA observations"
Galaxy clusters are the largest gravitationally bound systems in the Universe, offering unique laboratories to investigate the interplay between large-scale cosmological structures, the hot intracluster medium (ICM), and the regulatory role of Active Galactic Nuclei (AGN) feedback in resolving the long-standing cooling flow problem. Within cool-core clusters, the central Brightest Cluster Galaxy (BCG) frequently hosts a complex multi-phase gas reservoir, where cold molecular gas serves as the fuel for supermassive black hole (SMBH) growth. This thesis presents a dedicated study of the cold molecular gas reservoir in the galaxy cluster Abell 2495 (z = 0.07923), based on high-resolution ALMA Band 3 observations. To fully interpret these new data, we integrate our ALMA measurements with complementary multi-wavelength information, including deep Chandra X-ray imaging, VLT/MUSE optical H alpha line maps, and the precisely known position of the BCG from previous studies of this cluster. Abell 2495 represents a rare, highly disturbed system characterized by a spatial offset between the X-ray peak, the H alpha emission nebula, and the BCG, providing an ideal benchmark to explore how gas displacement impacts the AGN feeding and feedback cycle. We successfully detect and map the 106 GHz continuum and the CO(1-0) molecular line, from which we derive a total molecular gas mass of M_mol = (5.23 ± 0.33) × 10^8 M_?. The molecular gas peak is offset from the BCG core and radio continuum, aligning closely with the warm ionized gas. Furthermore, position-velocity diagrams reveal a coherent velocity gradient driven by cluster sloshing rather than a relaxed rotating disk, supporting a scenario where ICM sloshing modulates gas condensation and accretion onto the central SMBH to sustain a regulated feedback loop.