cgm_diagram_.jpeg

Arctomography

Collaboration: Sebastián López, Pasquier Noterdaeme, Felipe Barrientos, Nicolás Tejos, Cedric Ledoux, Evelyn Johnston, Giuseppe D'Ago 

The properties and distribution of gas around galaxies (the so-called circumgalactic medium, CGM) is key to the understanding of galaxy evolution. Until recently, absorption line spectroscopy towards bright background point sources provided the only way to probe CGM of distant galaxies. While information can be obtained using a large number of lines of sight, the spatial structure is expected to depend on the host galaxy properties. In this context, the technique of gravitational arc tomography has recently been pioneered in Chile: Integral field spectroscopy of gravitationally stretched sources provides hundreds of spectra that contain  absorption-line information of intervening galaxies in the field. Pasquier Noterdaeme has joined this "ARCTOMO" team, bringing his expertise on absorption line studies and derivation of gas incidence.