Fat cosmic ray tracks in charge-coupled devices
Abstract
Cosmic rays are particles from the upper atmosphere, which often leave bright spots and trails in images from telescope charge-coupled devices (CCDs). We investigate so-called "fat" cosmic rays seen in images from Vera C. Rubin Observatory and the Subaru Telescope. These tracks are much wider and brighter than typical cosmic ray tracks and therefore are more capable of obscuring data in science images. By understanding the origins of these tracks, we can better ensure that they do not interfere with on-sky data. We compare the properties of these tracks to simulated and theoretical models to identify both the particles causing these tracks as well as the reason for their excess spread. We propose that the origin of these tracks is cosmic ray protons, which deposit much greater charge in the CCDs than typical cosmic rays due to their lower velocities. The generated charges then repel each other while drifting through the detector, resulting in a track that is much wider than typical tracks.
- Publication:
-
Journal of Astronomical Telescopes, Instruments, and Systems
- Pub Date:
- April 2023
- DOI:
- 10.1117/1.JATIS.9.2.028006
- arXiv:
- arXiv:2306.11235
- Bibcode:
- 2023JATIS...9b8006G
- Keywords:
-
- cosmic rays;
- charge-coupled devices;
- instrument signature removal;
- protons;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 13 pages, 7 figures. Accepted to JATIS