So-called ‘Little Red Dots’ appeared in the very first deep extragalactic JWST surveys and their unusual properties have confounded astronomers ever since. They appear to be dominated by luminous point-like emission comprised of broad hydrogen emission lines and a continuum which rises both to the rest-frame UV and NIR, with an inflection around 4000A. They have generally ascribed to obscured AGN, but exhibit few other traits typically of accreting SMBHs. I will review what we know about these objects thus far and discuss potential origins.
LAM seminar
LAM seminar: Patricia Schady – The use of long GRBs as probes of the ISM in high redshift galaxies
With the launch of the highly successful Swift GRB mission 20 years ago came a step change in our understanding of GRBs in terms of their emission properties, their progenitors and their use as probes of star formation and the distant universe. In this talk I will focus on the use of the luminous, multi-wavelength afterglow to study the properties of the intervening attenuating dust and gas within the GRB host galaxy, and on how combing the afterglow absorption properties with host galaxy emission properties can further the potential of GRBs as unique probes of distant galaxies.
LAM seminar: Daniele Michilli – Fast radio bursts: what they are, why we care
I recently joined LAM with a project to detect fast radio bursts (FRBs) and use them to study the cosmos. In this talk, I will give an overview of the field of FRBs: what we know, where we stand, and what is about to happen. FRBs are flashes of radio waves visible from distant galaxies whose origin is obscure. However, they can be used as unprecedented tools to study the Universe thanks to their unique combination of short duration, high luminosity, and low frequencies. For example, they can be used to probe the interstellar medium, gather information on galaxy feedback processes, measure magnetic fields of other galaxies, and constrain the Hubble constant. In this regard, FRBs that are gravitationally lensed by intervening galaxies are a particularly interesting category yet to be explored. This is an exciting time for FRB science as new instruments promise to revolutionize the field, and I will discuss some of the most interesting prospects for the coming years.
