Prospects for observations of pulsars and pulsar wind nebulae with CTA

Abstract

The last few years have seen a revolution in very-high gamma-ray astronomy (VHE; E > 100 GeV) driven largely by a new generation of Cherenkov telescopes (namely the H.E.S.S. telescope array, the MAGIC and MAGIC-II large telescopes and the VERITAS telescope array). The Cherenkov Telescope Array (CTA) project foresees a factor of 5 to 10 improvement in sensitivity above 0.1 TeV, extending the accessible energy range to higher energies up to 100 TeV, in the Galactic cut-off regime, and down to a few tens GeV, covering the VHE photon spectrum with good energy and angular resolution. As a result of the fast development of the VHE field, the number of pulsar wind nebulae (PWNe) detected has increased from one PWN in the early '90s to more than two dozen firm candidates today. Also, the low energy threshold achieved and good sensitivity at TeV energies has resulted in the detection of pulsed emission from the Crab Pulsar (or its close environment) opening new and exiting expectations about the pulsed spectra of the high energy pulsars powering PWNe. Here we discuss the physics goals we aim to achieve with CTA on pulsar and PWNe physics evaluating the response of the instrument for different configurations. (C) 2012 Elsevier B.V. All rights reserved

Prospects for the detection of high-energy (E > 25 GeV) Fermi pulsars with the Cherenkov Telescope Array

“…Despite the harder high-energy spectrum (γ = 3.0), a simulation of a 50 h observation of the Crab pulsar above 1 TeV also yields a marginal detection (S=4) because of the contamination from the bright point-like (in gamma-rays) Crab nebula. This result is consistent with the simu- lations presented by de Oña-Wilhelmi et al (2013). It also demonstrates an improvement of the CTA performance compared with the currently operating IACTs.…”

“…In addition to the pulsars simulations, we also calculate independently CTA sensitivity curves for each pulsar, comparing them with results of the ctools analysis. Our results are compared with similar estimates reported in 1FHL (Ackermann et al 2013) and in de Oña-Wilhelmi et al (2013).…”

“…More detailed investigations of the point source emission from the 12 HE Fermi pulsars in VHE gamma-rays will be possible with the future ground-based IACT installations as the Cherenkov Telescope Array (CTA, see e.g. de Oña-Wilhelmi et al (2013) for the prospects for observations of VHE pulsars and Burtovoi & Zampieri (2016) for the VHE timing analysis of the Crab pulsar). This Cherenkov instrument will be a next-generation facility, consisting of two arrays in the northern and southern hemispheres (CTA-North and CTA-South) with more than one hundred telescopes in total (Actis et al 2011;Acharya et al 2013).…”

VHE Gamma-ray sources in view of the Cherenkov Telescope Array - A Review

“…MAGIC discovered the first VHE pulsar when it detected pulsed emission the Crab. VERITAS has shown that emission extends up to 400 GeV and MAGIC even reports pulsed emission beyond 1 TeV, as opposed to an exponential cutoff as might have been expected (see [24] and references within). HESS-II has reported pulsed emission from the Vela pulsar, but no indication of a VHE spectral extension yet.…”

“…VHE PWN are very extended (up to 1-2 • ) so their study will benefit from the wide field of view of CTA [24]. The large energy range covered by CTA will be crucial to understand cooling effects in the electron parent populations, including the resolution of internal structures and the possibility to disentangle between synchrotron or adiabatic losses.…”