12:00–1:00 pm ERC 401
Mandy Chen "Spatially-resolved kinematics of the circumgalactic medium (CGM) in active halos"
Being able to map out the low-density circumgalactic medium (CGM) with unprecedented sensitivity, the recent advent of high-throughput integral-field-unit (IFU) spectrographs has tremendously aided in our investigation of the diffuse CGM. Here I will present spatially-resolved kinematic measurements of the CGM (up to a scale of ~100kpc) around four AGNs between z=0.5 and z=1, using [OII] and [OIII] emission lines detected by VLT/MUSE as tracers. I will show the velocity structure functions (VSFs) constructed from such measurements, which exhibit a wide range of power-law slopes from 0 (i.e., completely flat) to 2/3 (i.e., consistent with the expectation from Kolmogorov turbulence). While the interpretation of these VSFs is not unique, this work demonstrates that spatially-resolved imaging spectroscopy provides the most detailed insights yet into the dynamical state of the tenuous CGM.
Elena Pinetti "A new path for dark matter searches: cross-correlation between gamma rays and gravitational tracers of the matter distribution"
Dark matter in cosmic structures is expected to produce signals that originate from its particle-like nature, among which the electromagnetic emission represents a relevant opportunity. However, this emission is very faint and contributes only to the unresolved background radiation. This background emission is isotropic at first order, but exhibits a degree of anisotropy since it originates from clustered dark matter haloes. This fact implies that the anisotropies in the radiation field will be correlated to the matter distribution in the Universe. One method to measure the level of this correlation is to use the cross-correlation technique and the angular power spectrum. I will describe this technique and some interesting applications, in particular one promising cross-correlation channel consists of considering neutral hydrogen as a novel tracer of the matter distribution and gamma rays as the tracer of dark matter particles. This technique can also be extended to include cosmic voids.
