The Transient program of the Cherenkov Telescope Array

Abstract

The Cherenkov Telescope Array (CTA) is the next generation high-energy gamma-ray observatory. It will improve the sensitivity of current instruments up to an order of magnitude, while providing energy coverage for photons from 20 GeV to at least 300 TeV to reach high redshifts and extreme accelerators and will give access to the shortest timescale phenomena. CTA is thus a uniquely powerful instrument for the exploration of the violent and variable universe. The ability to probe short timescales at the highest energies will allow CTA to explore the connection between accretion and ejection phenomena surrounding compact objects, investigate the processes occurring in relativistic outflows, and open up significant phase space for serendipitous discoveries. Aiming at playing a central role in the era of multi-messenger astrophysics, the CTA Transient program includes follow-up observations of a broad range of multi-wavelength and multi-messenger alerts, ranging from Galactic compact object binary systems to novel phenomena like Fast Radio Bursts. A promising case is that of gamma-ray bursts (GRBs), where CTA will for the first time enable high-statistics measurements above ∼ 10 GeV, probing new spectral components and shedding light on the physical processes at work in these systems. Dedicated programs searching for very-high-energy (VHE) gamma-ray counterparts to gravitational waves and high-energy neutrinos complete the CTA transients program. This contribution will introduce and outline the CTA Transients program. We will provide an overview of the various science topics and discuss the links to multi-messenger and multiwavelength observations.

Summary of the 36th ICRC Gamma-ray Indirect sessions

“…Currently only the Northern part of the sky is covered by surface arrays (HAWC [8,9], and Tibet AS+MD array [10]). A similar installation is also considered for the Southern hemisphere (SWGO, [11,12]). Some instruments combine both measurement techniques of gamma rays in a hybrid system.…”

The gravitational-wave follow-up program of the Cherenkov Telescope Array

“…This work was conducted in the context of the CTA Transients Working Group [44]. We gratefully acknowledge financial support from the agencies and organizations listed here: http://www.ctaobservatory.org/consortium_acknowledgments.…”

The Cherenkov Telescope Array

“…The CTA surveys will open up discovery space in an unbiased way and generate legacy datasets of long-lasting value. Several science projects of the CTA consortium can be found in this conference, see [5,6,7,8]. In a decade-long effort, CTA Consortium members have developed and built prototype telescopes, and validated their performance.…”