July 28, 2025 to August 1, 2025
Perimeter Institute for Theoretical Physics
America/Toronto timezone

The circumgalactic medium in emission and absorption, from dwarf galaxies to massive quasar hosts

Jul 30, 2025, 11:15 a.m.
10m
PI/1-100 - Theatre (Perimeter Institute for Theoretical Physics)

PI/1-100 - Theatre

Perimeter Institute for Theoretical Physics

190
Contributed Talk

Speaker

Dr Sean Johnson

Description

The circum-galactic medium (CGM) is at the nexus of the gas inflows and outflows that regulate galaxy evolution. Consequently, the CGM provides an ideal laboratory for studying galaxy fueling, feedback, and interactions.
In the last decade, the simultaneous availability of UV spectra from the Cosmic Origins Spectrograph, deep integral field spectrographs, and wide galaxy redshift surveys have revolutionized our ability to characterize the CGM empirically. I will review recent progress enabled by the Cosmic Ultraviolet Baryon Survey (CUBS) and MUSE Quasar Blind Emitter Survey (MUSEQuBES), which combine these data for 31 intermediate redshift quasar fields. These surveys simultaneously provide for the first studies of physical conditions and abundances of the CGM and IGM around low-mass dwarf galaxies that constrain the physical conditions and abundances of the gas while also enabling the discovery of giant rest-frame optical emission nebulae around quasar hosts. I will highlight enlightening case studies, including filamentary accretion from 100 kpc scales into the ISM of a massive quasar host confirmed by down-the-barrel inflows observed in the UV and the first studies of relative abundances in the CGM/IGM around isolated dwarf galaxies that reveal surprisingly high metallicity and low [C/O] and [N/O] ratios, suggestive of core-collapse supernova outflows with modest mass loading.

Primary Theme Galactic to intergalactic scales
Secondary Theme Diffuse to dense structures
Presenter's Name Sean D. Johnson
Presenter's Email Address [email protected]
Keywords IGM, CGM, quasars, dwarf galaxies
Recording Permission YES
Virtual Audience Permission YES
Photography Permission YES
If your talk is not accepted for a contributed talk, would you be interested in presenting a fireslide/lightning talk? No
If your fireslide/lighting talk is not accepted, would you be interested in presenting a poster? No

Author

Dr Sean Johnson

Presentation materials

There are no materials yet.

External references