Cherenkov Telescope Array

The CTA will be the most powerful γ-detector, built on the advаnces of its predecessors (H.E.S.S., VERITAS and MAGIC), and is expected to register over 1,000 new objects. In order to cover the largest possible range of energies, three groups of telescopes are planned: 70 small-sized, 40 medium-sized and 8 large-sized, set at two sites: one in the northern hemisphere (the Canary Islands) and one in the southern hemisphere (Chile). 

Different size telescopes


Each telescope will have its own specific dimensions, but they will all have a segmented cosmic ray detection mirror, a high-speed camera that records the registered rays and mounts that allow fast guidance to any direction of the sky.

Large Size Telescopes

Since low-energy gamma rays produce less Cherenkov radiation, γ-telescopes with large
mirrors are needed to record it. The mirrors of the large-sized telescopes will be parabolic,
with a diameter of 23 m. The entire structure will weigh 50 tons, but this does not prevent it
from being extremely mobile - the aim is to re-position to any point in the sky within 20

Medium-sized Telescopes

Medium-sized telescopes will have mirrors with a diameter of 12 meters, and their large field
of view allows for large-scale night-sky γ-studies.

Galactic Plane

Observations of the galactic plane will also be a target for CTA to discover new and
unexpected galactic phenomena, whole classes of new sources of variable behavior, and a
large number of high-energy sources such as supernova remnants and strong pulsar winds.

So far, a prototype of a middle-sized size telescope has been built and tested, as well as three different variants of a small-sized telescope.
In October 2018, the first large-sized telescope was inaugurated. It is expected that the entire infrastructure will be completed and put into operation in 2025.

Areas of research

Galactic Center

One of CTA's main goals will be to study the area of ​​the Galactic Center. It is rich in high
energy sources: the supermassive black hole in the center, as well as thick molecular
clouds, areas of active star formation, supernova remnants and others. This is one of the
most studied regions of the sky at many wavelengths and the CTA will contribute with
precise measurements at the highest energies.

Big Magellanic Cloud

Another object of interest is the Big Magellanic Cloud - a galaxy-companion of the Milky
Way, full of unusual objects: star formation regions, stellar clusters, supernova remnants. An
advantage is that this galaxy is so close to the Milky Way and is also very active: the star
formation rate is about 1/10 of that of the Milky Way, at an area of ​​only 2% of that of the
Milky Way. Over 60 supernova remnants, hundreds of H II areas, various bubbles and shells
have been found.

Small-sized Telescopes

The small-sized telescopes will be sensitive to the most energetic γ-rays coming from our
galaxy. Since it is more suitable for observation from the southern hemisphere, the small
telescopes will have the largest number and will be installed only at the Chile site. The
diameter of their mirrors is 4 m and their field of view is very large, 9 degrees.

Galaxy Clusters

Galaxy clusters are expected to contain protons and electrons accelerated by structure
formation processes, member galaxies or active galactic nuclei. The observation of diffuse
synchrotron radio emission in several such clusters confirms the presence of such electrons.
The CTA will be able to record diffuse γ-radiation from one of the closest galactic clusters,

Cosmic Rays

Cosmic rays may play an important role in regulating the star formation process, so it is
important to understand the mechanism of acceleration, propagation and their interactions.
Deep observations of various objects are needed to investigate the relationship between γ-
radiation and star formation and the influence of cosmic rays on their surrounding

Galactic Nuclei

Other important observations are those of radio-loud active galactic nuclei. Regular
observations, especially of blazars and radio-galaxies, will provide information not only about
the physics of active galactic nuclei, but also about the study of γ-rays, cosmic rays and
fundamental physics. The active galactic nuclei will be the main objects detected by the
proposed study of ¼ of the extragalactic sky at energies between 100 GeV and 10 TeV.

CTA Team

Evgeni P. Ovcharov

Assoc. Prof., PhD

Call: (+3592) 81-61-717

Email: evgeni[at]phys.uni-sofia.bg

    Galina Maneva

    Assoc. Professor, Ph.D.

    Call: (+359) 2 979-5568

    Email: [email protected]

      Martin Makariev

      Assistant Professor, Ph.D.

      Call: (+359) 2 97-95-5549

      Email: [email protected]

        Milen Minev

        Ph.D. Student

          Petar Temnikov

          Professor, PhD

          Call: (+359) 2 9795568

          Email: [email protected]

            Vassil Verguilov


              Vladimir Bozhilov

              Head Assistant Prof., PhD

              Call: (+3592) 81-61-413

              Email: vbozhilov[at]phys.uni-sofia.bg