A study of blazar PKS 1424−418 was carried out using multi-waveband data collected by the Fermi Large Area Telescope (Fermi-LAT), Swift X-Ray Telescope (Swift-XRT), Swift UltraViolet and Optical Telescope (Swift-UVOT), and Small and Moderate Aperture Research Telescope System (SMARTS) between MJD 56000 and MJD 56600 (2012 March 14–2013 November 4). Two flaring episodes were identified by analysing the gamma-ray light curve. Simultaneous multi-waveband spectral energy distributions (SEDs) were obtained for those two flaring periods. A cross-correlation analysis of infrared (IR)–optical and γ-ray data suggested that the emission originated from the same region. We have set a lower limit for the Doppler factor using the highest energy photon observed from this source during the flaring periods, which should be >12. The broad-band emission mechanism was studied by modelling the SED using the leptonic emission mechanism.
A study of the gravitationally lensed blazar PKS 1830-211 was carried out using multi-wave band data collected by Fermi-LAT, Swift-XRT, and Swift-UVOT telescopes between MJD 58400 to MJD 58800 (2018 October 9–2019 November 13). Flaring states were identified by analyzing the γ-ray light curve. Simultaneous multi-wave band spectral energy distributions (SEDs) were obtained for these flaring periods. A cross-correlation analysis of the multi-wave band data was carried out, which suggested a common origin of the γ-ray and X-ray emission. The broadband emission mechanism was studied by modeling the SED using a leptonic model. Physical parameters of the blazar were estimated from the broadband SED modeling. The blazar PKS 1830-211 is gravitationally lensed by at least two galaxies and has been extensively studied in the literature because of this property. The self-correlation of the γ-ray light curve was studied to identify the signature of lensing, but no conclusive evidence of correlation was found at the expected time delay of 26 days.
The prototype Large-Sized Telescope (LST-1) of the Cherenkov Telescope Array Observatory (CTAO) is in commissioning phase at the Observatorio del Roque de Los Muchachos at 2200 m a.s.l. in La Palma (Canary Islands, Spain). LST-1 is a 23-m diameter telescope and is the first of four that will compose the LST part of the CTAO Northern array. The LST subarray is optimized to provide the best sensitivity for gamma rays in the 20 GeV -200 GeV energy range. The MAGIC telescopes, which are located approximately 100 m from the LST-1, is operating as a two 17-m telescope stereoscopic system for more than 14 years. LST-1 and MAGIC routinely perform joint observations of gamma-ray sources to exploit the potential of the three-telescope system. This contribution describes the analysis pipeline and evaluates the performance of the system using Monte Carlo simulations and data on the Crab Nebula. The sensitivity achieved during joint observations with MAGIC and LST-1 is about 30% higher than that of MAGIC alone.
There are several types of Galactic sources that can potentially accelerate charged particles up to GeV and TeV energies. These accelerated particles can produce Very High Energy (E>100 GeV) gamma-ray emission through different non-thermal processes such as inverse Compton scattering of ambient photon fields by accelerated electrons or pion decay after proton-proton collisions.Here we present highlight results of observations with the MAGIC telescopes on Galactic sources: millisecond pulsars, supernova remnants (SNRs), pulsar wind nebulae (PWNe), novae and binary systems. In particular, we present the promising PeVatron candidate SNR G106.3+2.7 containing an energetic PWN named Boomerang. Also, in the ongoing search for new source classes we looked for very-high-energy emission from the millisecond pulsar PSR J0218+4232 that has long been considered as one of the best candidates. Furthermore, we present the observations during an exceptionally bright X-ray outburst from the low mass X-ray binary MAXI J1820+070. Finally, we highlight the MAGIC results of the first nova detected at VHEs: RS Ophiuchi, a recurrent symbiotic nova located in the Milky Way. The detection with the MAGIC telescopes proves a hadronic origin of the the gamma-ray emission, and helps in understanding the contribution of novae to the cosmic-ray budget.
Extreme high-frequency-peaked BL Lac objects (EHBLs) are the most energetic persistent sources in the Universe. They are characterized by a spectral energy distribution (SED) featuring a synchrotron peak energy above 1 keV. 1ES 2344+514 is a blazar known to behave as an EHBL intermittently. Until now, its EHBL nature was only reported during flares, but a coherent picture is missing as unbiased monitoring campaigns are lacking. This work presents the longest observing campaign from radio to very-high-energy (VHE) frequencies performed so far on 1ES2344+514. Using observations during 2019-2021, we carry out a systematic investigation of the intermittent EHBL phases. Together with MAGIC, the dataset also includes X-ray observations from NuSTAR, XMM-Newton, and AstroSAT, providing an unprecedented determination of the two SED components. For the first time we report a clear EHBL behaviour during a low flux activity in 1ES 2344+514. It implies a significant hardening of the electron distribution inside the jet independent of flux. We also detect a bright X-ray state characterized by an unusually soft spectra, thus violating the harder-when-brighter relation typically found in blazars. The SED study further reveals an excess in the ultraviolet data with respect to the extrapolation of the X-ray spectrum, suggesting at least two regions contributing to the synchrotron flux. Finally we investigate a gamma-ray flare not accompanied by an X-ray counterpart. This peculiar outburst is interpreted using a time-dependent model involving two emitting components.
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