SDM: AGN-Driven Multiphase Outflows | Non-Fellow Ticket

Outflows in galaxies hosting active galactic nuclei (AGN) are widely regarded as a key mechanism for removing gas from galaxies, potentially leading to the suppression of star formation over time. Over the past decade, the advent of advanced instruments on large telescopes has enabled observers to trace these outflows across multiple gas phases. At the same time, developments in numerical techniques have significantly advanced our ability to model AGN-driven feedback in cosmological and zoom-in simulations in the broader context of galaxy evolution. Observations and simulations are closely intertwined: empirical measurements—such as coupling efficiency, outflow kinetic power, and gas composition—serve as vital constraints for refining theoretical models and feedback prescriptions, while simulations provide crucial guidance for interpreting observational data. This specialist discussion aims to bring together observers and theorists working on AGN feedback, with a particular focus on researchers studying multi-phase outflows.

Organising this session is especially timely, given the growing number of observations of outflows in previously underexplored gas phases (e.g., warm molecular gas) in low and high-redshift galaxies via JWST. Combined with archival UV, optical, sub-mm and radio data, these multi-wavelength observations now allow us to assess the relative contributions of different gas phases to outflow rates, kinetic energy and coupling efficiencies. At the same time, advances in numerical techniques mean that simulations are spanning larger dynamic ranges and incorporating more realistic modelling of AGN radiation, winds and jets, alongside multiphase ISM prescriptions. Together, these developments allow for more direct and detailed comparisons across gas phases.

The specialist discussion will be structured into two sessions: one focused on observational studies and the other on theoretical perspectives.

1. Observational Studies of Multi-Phase Outflows: This session will explore both spatially resolved and unresolved observations across various gas phases—ionised, cold molecular, warm molecular, and neutral, at both low and high redshift. Key questions include: What is the morphology or how extended are these outflows in each gas phase? What is the coupling efficiency in each phase?

1. Theoretical Modelling of Multi-Phase Outflows: This session will highlight current efforts and recent advances in simulating multi-phase outflows, examining how realistic feedback processes interact with different gas phases and drive multi-phase outflows. Key questions mirror the observational counterpart: How well do theoretical predictions align with observations?

1. Assessing the Impact of outflows: Across both sessions, we will discuss emerging evidence for the broader consequences of AGN-driven outflows, including their role in regulating star formation, altering molecular gas content, and redistributing metals within galaxies.

Proposed timings

10:00-10:30 = Tea/Coffee

10:30-12:30 = First session

12:30-13:30 = Lunch

13:30-15:30 = Second session

15:30-16:00 = Tea/Coffee

Abstract submission deadline 5th August: https://forms.gle/6JMjL4j6vLQ1jfm4A

Invited Speakers

Debora Sijacki (Cambridge, UK)

Michele Perna (CAB, Spain)

Organisers

Co-Chairs: Darshan Kakkad (ZCAhIG0gISBrYWtrYWQgfCBoZXJ0cyAhIGFjICEgdWs=) & Martin Bourne (bSAhIGJvdXJuZSB8IGhlcnRzICEgYWMgISB1aw==), University of Hertfordshire

SOC: Chris Harrison (NewCastle), Martin Krause (Hertfordshire), Raffaella Morganti (Groningen), Cristina Ramos-Almeida (IAC)

Photo Credit:

Left panel: HST/ ALMA/ VLA/ M. Meenakshi/ D. Mukherjee/ A. Audibert (Audibert et al. 2023)

Middle panel: ESO/M. Kornmesser (Maiolino et al. 2017)

Right panel: From Talbot, Bourne & Sijacki (2021)

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