The cold Circumgalactic Medium and its role in galaxy evolution

Event Date:
2025-03-17T16:00:00
2025-03-17T17:00:00
Event Location:
HENN 318
Speaker:
Paola Andreani, European Southern Observatory
Related Upcoming Events:
Astronomy Colloquia
Intended Audience:
Everyone
Local Contact:

Allison Man (aman@phas.ubc.ca) and Brett Gladman (gladman@astro.ubc.ca)

All are welcome to this event!

Event Information:

Abstract:

Galaxies are not isolated systems but complex ecosystems. Current theories predict that they form in dark-matter halos connected by a network of filaments, mainly made of gas, but for galaxies to keep forming stars, fresh gas needs to be continuously accreted through filaments onto galaxy halos. Some of this gas is pristine, of cosmological origin, while some is recycled from galaxy discs by energetic events such as powerful winds. This cycle of gas inflow and outflow creates a reservoir between a galaxy's disc and its outer environment, known as the circumgalactic medium (CGM).

Recent studies are showing that a -- so far unconstrained -- fraction of the CGM mass may reside in the cold molecular and atomic phase, especially in high-redshift dense environments. These gas phases, together with the warmer ionised phase, can be studied through bright far-infrared and sub-millimetre emission lines such as [CII](158um), [OIII](88um), CI[1-0](609um) CI[2-1](370um), and the rotational transitions of CO.

Using observations from the largest ground-based and space telescopes (ALMA and JWST), combined with traditional and AI-driven analysis techniques, and advanced simulations, we are undertaking a project making use of gas emission, kinematics, excitation and magnetic fields to address key questions in galaxy evolution: Is there sufficient gas and dust to solve the cosmological missing baryon puzzle? How does outflowing gas that reaches the CGM regulate star formation in galaxy discs? How do galaxies acquire material to sustain star formation via inflows? 

 

Bio:

Paola received her PhD in Physics from the Universita' di Roma La Sapienza, Rome, Italy and has held positions at the European Southern Observatory (ESO), at the Instituto Nazionale di Astrofisica (INAF) in Rome, Italy, the Max-Planck Institute in Munich, Germany, at the University of Padova in Padua, Italy, the Italian National Council of Research (CNR) and the Italian Ministry for University Research, Science, and Technology (MURST), and the Institut Astrophysique (IAP) in Paris, France.

She is currently Head of the ESO-Garching Office for Science and Chair of the Astronomer Faculty with academic interests in Cosmology and the Early Universe, the evolution of galaxies and the ISM and QSOs, observational cosmology, tand far infrared and submillimetric extragalactic backgrounds. 

Learn More:

Links:

Add to Calendar 2025-03-17T16:00:00 2025-03-17T17:00:00 The cold Circumgalactic Medium and its role in galaxy evolution Event Information: Abstract: Galaxies are not isolated systems but complex ecosystems. Current theories predict that they form in dark-matter halos connected by a network of filaments, mainly made of gas, but for galaxies to keep forming stars, fresh gas needs to be continuously accreted through filaments onto galaxy halos. Some of this gas is pristine, of cosmological origin, while some is recycled from galaxy discs by energetic events such as powerful winds. This cycle of gas inflow and outflow creates a reservoir between a galaxy's disc and its outer environment, known as the circumgalactic medium (CGM). Recent studies are showing that a -- so far unconstrained -- fraction of the CGM mass may reside in the cold molecular and atomic phase, especially in high-redshift dense environments. These gas phases, together with the warmer ionised phase, can be studied through bright far-infrared and sub-millimetre emission lines such as [CII](158um), [OIII](88um), CI[1-0](609um) CI[2-1](370um), and the rotational transitions of CO. Using observations from the largest ground-based and space telescopes (ALMA and JWST), combined with traditional and AI-driven analysis techniques, and advanced simulations, we are undertaking a project making use of gas emission, kinematics, excitation and magnetic fields to address key questions in galaxy evolution: Is there sufficient gas and dust to solve the cosmological missing baryon puzzle? How does outflowing gas that reaches the CGM regulate star formation in galaxy discs? How do galaxies acquire material to sustain star formation via inflows?    Bio: Paola received her PhD in Physics from the Universita' di Roma La Sapienza, Rome, Italy and has held positions at the European Southern Observatory (ESO), at the Instituto Nazionale di Astrofisica (INAF) in Rome, Italy, the Max-Planck Institute in Munich, Germany, at the University of Padova in Padua, Italy, the Italian National Council of Research (CNR) and the Italian Ministry for University Research, Science, and Technology (MURST), and the Institut Astrophysique (IAP) in Paris, France. She is currently Head of the ESO-Garching Office for Science and Chair of the Astronomer Faculty with academic interests in Cosmology and the Early Universe, the evolution of galaxies and the ISM and QSOs, observational cosmology, tand far infrared and submillimetric extragalactic backgrounds.  Learn More: About Galaxy Evolution: https://science.nasa.gov/universe/galaxies/evolution/ About the Circumgalactic Medium (CGM): https://ui.adsabs.harvard.edu/abs/2017ARA%26A..55..389T/abstract About the European Southern Observatory (ESO): https://www.eso.org/public/about-eso/ About ESO Telescopes: https://www.eso.org/public/teles-instr/  Links: Discover Paulo Andreani's research website: https://www.eso.org/~pandrean/index.html See article/images of the CMG in "Probing the Circumgalactic Medium with X-Ray Absorption Lines" from SpringNature: https://link.springer.com/referenceworkentry/10.1007/978-981-16-4544-0_112-1/figures/1  Event Location: HENN 318