With the help of MAGIC telescopes and the NASA space probe Fermi, an international team of astronomers has discovered a new source of high-energy gamma-ray emission around the supernova remnant (SNR) G24.7 + 0.6. The detection of the new source called MAGIC J1
Supernova remnants are essentially remnants of massive stars that ended their lives in huge explosions known as supernovae. Astronomers generally distinguish three types of SNRs, one of which is the compound SNR – these have fast spreading shells from the supernova pressure wave, accompanied by wind mists driven by young pulsars formed in the explosions.
Observations show that composite SNRs are known to accelerate particles to very high energies (VHE) of up to hundreds of TeV or above in their expanding bursts or the relativistic wind surrounding the energetic pulsar. Therefore, such objects are an excellent target for observations focused on finding new sources of VHE emissions.
The approximately 16,300 light-years away SNR G24.7 + 0.6 is an example of a middle-aged radio (about 9,500 years old) gamma-ray composite SNR. A group of astronomers studied this remnant with the MAGIC system (Major Atmospheric Gamma Imaging Cherenkov Telescopes) at the Roque de los Muchachos Observatory in the Canary Islands and the Large Area Telescope (LAT) aboard the NASA Fermi Gamma-ray Space telescope ,
The data provided by these telescopes allowed the team to identify a VHE emission from an extended source that was 0.34 degrees from the center of G24.7 + 0.6 and was named MAGIC J1835-069.
We study the interesting region around SNR G24.7 + 0.6 with Fermi-LAT in the energy range between 60 MeV and 500 GeV and use the MAGIC telescopes to study the region to study the spectral response above 150 GeV. LAT observed to limit the emission range by the SNR, "the researchers write in the paper.
The MAGIC J1835-069 emission was detected at energies above 150 GeV and detected up to 5 TeV, and the spectrum of this source is represented by a power law function Spectral index of 2.74 well represented.
The emission of MAGIC J1835-069 also has a projected size of about 98 light-years and shows an extended morphology.The newly found source lies between two known extended sources, those of Fermi-LAT above of 10 GeV, namely FGES J1836.5-0652 and FGES J1834.1-0706.
The origin of the VHE gamma-ray emission of MAGIC J1835-06 9 remains uncertain due to the complexity of the neighboring region G24.7 + 0.6. However, the authors suggest that this could be explained by cosmic rays that are accelerated within the remainder by proton-proton collisions with the carbon monoxide-rich surrounding medium.
"Results of the proton-proton interaction between the supernova and the CO-rich environment," the researchers concluded.
The fading spirit of a long dead star
MAGIC Collaboration. Discovery of the emission of TeV gamma rays from the vicinity of the supernova remnant G24.7 + 0.6 by MAGIC. arXiv: 1812.04854 [astro-ph.HE]. arxiv.org/abs/1812.04854