Measuring of the Hubble Constant with hardware stereo trigger between CTA-LST and MAGIC telescopes

Research Project

Project/Area Number	23K22497
Project/Area Number (Other)	22H01226 (2022-2023)
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Multi-year Fund (2024) Single-year Grants (2022-2023)
Section	一般
Review Section	Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
Research Institution	The University of Tokyo
Principal Investigator	Mazin Daniel 東京大学, 宇宙線研究所, 特任教授 (90747990)
Co-Investigator(Kenkyū-buntansha)	Vovk Ievgen 東京大学, 宇宙線研究所, 助教 (20899405) 手嶋政廣東京大学, 宇宙線研究所, グローバルフェロー (40197778) 齋藤隆之東京大学, 宇宙線研究所, 助教 (60713419) 高橋光成名古屋大学, 宇宙地球環境研究所, 特任助教 (60838960)
Project Period (FY)	2022-04-01 – 2025-03-31
Project Status	Granted (Fiscal Year 2024)
Budget Amount *help	¥15,600,000 (Direct Cost: ¥12,000,000、Indirect Cost: ¥3,600,000) Fiscal Year 2024: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000) Fiscal Year 2023: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000) Fiscal Year 2022: ¥7,020,000 (Direct Cost: ¥5,400,000、Indirect Cost: ¥1,620,000)
Keywords	Hubble constant / Cherenkov telescopes / Hardware stereo trigger / gamma-ray / Cherenkov / Hubble Constant / gamma-rays / hardware trigger / H0 constant / EBL / IACT / Trigger / gamma rays
Outline of Research at the Start	We will take data on flaring AGNs and GRBs with the new trigger system. We will analyse joint CTA-LST and MAGIC data and derive constraints on the extragalactic background light as well as the Hubble Constant H0. We also look into a new technology of Hollow Core Fibers to improve the trigger system.
Outline of Annual Research Achievements	The stereo hardware trigger has been installed and validated. In particular, we purchased and deployed a new trigger cable between the LST camera and MAGIC counting house shortening the trigger travel time by about 500ns compared to the previous installation. This is important to deliver the LST trigger in time to build a coincidence trigger with the MAGIC telescopes because MAGIC telescopes have a relatively short analog buffer length. We also installed a new firmware in MAGIC trigger system and developed the software code to control and monitor zenith and azimuth dependent trigger delays between LST and MAGIC telescopes. The trigger timing has been adjusted and several test data sets has been taken in hardware stereo mode. In the same time work on methodology to derive constraints on the density of the Extragalactic Background Light has been done, which can be directly used to constrain the Hubble constant H0.
Current Status of Research Progress	Current Status of Research Progress 2: Research has progressed on the whole more than it was originally planned. Reason The progress of the project is within the schedule. The hardware part of the project has been designed, deployed and commissioned. The evaluation of the performance is ongoing.
Strategy for Future Research Activity	In FY2023 we will study the actual performance and take data on various gamma-ray sources. We expect several trips to La Palma to polish the performance of the trigger and make it to a standard trigger system between LST1 and MAGIC telescopes. We also expect to take first data with hardware stereo trigger on extragalactic sources to derive preliminary limits on the H0 constant.