First measurements and upgrade plans of the MAGIC intensity interferometer
Abstract
The two MAGIC 17-m diameter Imaging Atmospheric Cherenkov Telescopes have been equipped to work also as an intensity interferometer with a deadtime-free, 4-channel, GPU-based, real-time correlator. Operating with baselines between approx. 40 and 90 m the MAGIC interferometer is able to measure stellar diameters of 0.5-1 mas in the 400-440 nm wavelength range with a sensitivity roughly 10 times better than that achieved in the 1970s by the Narrabri Stellar Intensity Interferometer. Besides, active mirror control allows to split the primary mirrors into sub-mirrors. This allows to make simultaneous calibration measurements of the zero-baseline correlation or to simultaneously collect six baselines below 17 m with almost arbitrary orientation, corresponding to angular scales of approx. 1-50 mas. We plan to perform test observations adding the nearby Cherenkov Telescope Array (CTA) LST-1 23 m diameter telescope by next year. All three telescope pairs will be correlated simultaneously. Adding LST-1 is expected to increase the sensitivity by at least 1 mag and significantly improve the u-v plane coverage. If successful, the proposed correlator setup is scalable enough to be implemented to the full CTA arrays.
Keywords
Cite
@article{arxiv.2209.14844,
title = {First measurements and upgrade plans of the MAGIC intensity interferometer},
author = {Juan Cortina and V. A. Acciari and A. Biland and E. Colombo and C. da Costa and C. Delgado and C. Diaz and M. Fiori and D. Fink and T. Hassan and I. Jimenez-Martinez and E. Lyard and M. Mariotti and G. Martinez and R. Mirzoyan and G. Naletto and M. Polo and N. Produit and J. J. Rodriguez and T. Schweizer and R. Walter and C. W. Wunderlich and L. Zampieri and the MAGIC and LST collaborations},
journal= {arXiv preprint arXiv:2209.14844},
year = {2022}
}
Comments
15 pages, 9 figures, 1 table, SPIE Astronomical Telescopes + Instrumentation 2022