| The discovery of this source, TeV J2032+4130, is of particular interest because there are only a few very high energy sources in our Galaxy; most of them lie outside our Galaxy.
Additionally, this source does not show any counterpart at other wavelengths, notably at X-ray wavelengths. This team was also involved in the recent discovery of a similar unidentified source, suggesting the emergence of a new class of high energy gamma-ray sources of unknown nature.
The source TeV J2032+4130 has very interesting features. It is most likely located within our own Galaxy, which is remarkable since there are only a few very high energy gamma ray sources in our Galaxy. The centre of our Galaxy is a famous gamma ray source. Another well-known source is the Crab Nebula (see right picture), the remnant of a supernova explosion. In both cases, the corresponding sources also have strong emission at X-ray wavelengths, suggesting the presence of accelerated electrons.
On the contrary, TeV 2032+4130 does not show any counterpart at other wavelengths, notably at X-ray energies. The lack (or at least the low level) of X-ray emission of TeV 2032+4130 suggests that the gamma ray emission arises from the interaction of accelerated cosmic rays with the local ambient matter.
TeV J2032+4130 is located in the Cygnus region, an extremely active star-formation region. It contains a large number of X-ray and low energy gamma-ray sources. To explain the gamma rays emitted by TeV J2032+4130, the HEGRA collaboration looked for sites in this region that could accelerate cosmic ray particles to high enough energy. Such sites could be supernova remnants, expanding clouds of gas that represent the outer layers of exploded stars named supernovae. However, no such supernova remnant has been identified yet in this region. The team believes that TeV J2032+4130 might be related to the “OB stellar association” Cygnus OB2. An OB association is a grouping of very hot and massive young stars. Such an association is named “OB” because these stars have O and B spectral types. Cygnus OB2 is thought to be powering the entire region via the intense stellar winds emanating from its stars. |
