# Galaxy Clusters as Tele-ALP-scopes

- Institution: CERN
- Department: TH Theoretical Seminar
- Speaker: Joseph Conlon
- Year: 2015
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3018202)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Teens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

Axion-like particles have good theoretical motivation and are characterized by conversion to photons in astrophysical magnetic fields. Galaxy clusters are the most efficient convertors of axion-like particles to photons in the universe. I discuss the physics and phenomenology of ALPs, and describe their astrophysical implications, with particular reference to the recently observed 3.5 keV X-ray line that is a candidate for a dark matter decay line. I discuss interpretations of this line in terms of dark matter decaying to an axion-like particle, that then converts to a photon in cluster magnetic fields, and describe the compatibility of this scenario with data and the different phenomenology for cool-core and non-cool-core clusters..

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## Lectures

1. [Galaxy Clusters as Tele-ALP-scopes](https://invisiblenetwork.ai/learn/cern/3018202/7432368a8f71), 1 h 6 min (CERN's player)