Upgrade of MAGIC Telescopes
11 March 2015
The two MAGIC telescopes at the Roque de los Muchachos Observatory on the Canary island of La Palma (Max Planck Institute for Physics/R. Wagner).
by Razmik Mirzoyan
MAGIC project leader at the Max Planck Institute for Physics, Munich, and spokesperson of the MAGIC Collaboration
Both MAGIC telescopes were upgraded about 2.5 years ago and now they are running with 1039 fine pixel (0.10°) cameras in the coincidence (stereo) mode. The standard trigger provides an energy threshold of ~ 50 GeV. Currently we are evaluating the results of the SUM-Trigger, which allows us lowering the trigger threshold down to ~ 35 GeV. Now both telescopes are using a 1.64 GSample/s readouts based on DRS4 chips. During last summer we changed about one third of the mirrors on the MAGIC-I telescope, which were in operation since 2004, and also a small number of mirrors on the MAGIC-II telescope. I have been involved with the MAGIC telescopes since the very first days of their operation and I can say with certainty that these were never in such a good shape as they are now.
All researchers involved in the collaboration are really enjoying pointing the telescopes to the skies and picking sources to find, sometimes unexpectedly, highly interesting results. Last year we were literally flooded by novel results and, although we published a really large number of peer-reviewed papers, we still have almost triple as many results in the publication queue. Trying to cope with this situation, we have introduced the position of “publication manager” whose sole task is to accelerate the publications. What I find very interesting and pleasing is the large flux of young female researchers who are in increasingly large numbers joining our collaboration, obviously attracted by the very dynamic research.
Just to name a few highly interesting results, recently we succeeded in measuring the pulsations from the Crab pulsar, extending to at least 2 TeV, and we could not observe any tailing off of the spectrum yet. Even a few years ago nobody could imagine this. In a series of five papers (the fifth one is under review for publication) on the same Crab pulsar, spread over the last several years, we could experimentally measure several very novel features: e.g. the spectrum starting from 25 GeV and extending to TeV energies, indicating extreme acceleration of electrons in this compact object (the size of a pulsar is estimated to be ~ 10km), the existence of the bridge component of the emission at higher energies, very sharp pulse time profiles, inverse-Compton scattering mechanism for energies above 10 GeV, and many other interesting features.
From qualitative measurements we moved to precision measurements of the parameters of the Crab pulsar, providing accurate input for novel theories. I should mention that with every next measurement of MAGIC we showed that none of the existing or currently developed novel theoretical models was able to satisfactorily describe the experimental data. In my opinion the pulsars, along with the black holes, are the most complex objects in the sky. We are anticipating novel, quantitative theory models to appear in the next years, which can be tested with our experimental measurements.
Another example of highly interesting results, is our recent finding of the most distant source at VHE energies, S3 0218 at a redshift of 0.944. We detected the delayed flare from this object, due to gravitational lensing, 11 days after the first alert reported by the Fermi satellite mission. So with this measurement we doubled the redshift reach of IACTs. The physics implications of this detection are still under evaluation.
I want also to mention our recent article on a big flare from the radio galaxy IC 310, which appeared in the SCIENCE magazine. The ~ 5 minutes signal variability received from this object was about five times shorter than the size of the event horizon of the black hole residing in IC 310. We suggested a novel theoretical model, a pulsar like mechanism for the black hole, in order to explain this unusual behavior.
We are confident that the next five years will be the most productive time in the history of MAGIC and that we will continue to strongly contribute to the physics of cosmic rays, astroparticle physics and cosmology. We are looking forward to the exciting future of ground-based gamma-ray astronomy, which soon will be crowned by the CTA arrays.
Submitted by Eleni Chatzichristou
APPEC Communications Officer