(ORDO NEWS) — Astronomers in Costa Rica and Australia have reported new supernova remnants from a gamma source known as FHES J1723.5-0501. The researchers found that this source is a supernova remnant, and gave it the designation G17.8 + 16.7.
Supernova remnants are diffuse, expanding structures created by a supernova explosion. They contain erupting material that is expanding from the explosion, as well as other material from interstellar space that was captured by the shockwave passing from the side of the exploding star.
The study of supernova remnants is of interest to astronomers, since they play a key role in the evolution of galaxies, as they scatter the chemical elements formed as a result of stellar explosions, as well as the energy spent on heating the interstellar medium. It is also believed that supernova remnants are responsible for the acceleration of galactic cosmic rays.
Object FHES J1723.5-0501 is a gamma-ray source detected outside the galactic plane by NASA‘s Fermi spacecraft. Previous observations have shown the presence of an unclassifiable radio envelope in the vicinity of the southwestern edge of this source, indicating that FHES J1723.5-0501 may be associated with supernova remnants or a pulsar wind nebula.
In a new work, a group of astronomers led by Miguel Araya from the University of Costa Rica provides new evidence that FHES J1723.5-0501 is a supernova remnant. This study is based on an analysis of historical data collected primarily from the Very Large Array Sky Survey (NVSS) and the Continuum map of the HI Parkes All-Sky Survey (CHIPASS).
According to the study, G17.8 + 16.7 is a well-defined elliptical shell with bright borders that is denser, brighter, and well-defined eastward. The size of this radio envelope is 51 to 45 arc minutes.
The total radiation flux density from the side of the G17.8 + 16.7 source at a frequency of 1.4 gigahertz is 2.1 yang, while at a frequency of 2.3 gigahertz it is equivalent to 1.45 yang. These measurements allowed us to calculate the spectral index at two points, which was approximately -0.75. This value of the spectral index is in good agreement with nonthermal radiation from supernova remnants, which actively emit synchrotron radiation.
According to these results, supernova remnants SNR G17.8 + 16.7 are located between 4,500 and 11,400 light-years from Earth. Astronomers believe that these supernova remnants are approximately 10,000 years old, but they do not completely rule out alternative estimates of the object’s age. Additional observations will be required to resolve these uncertainties, the authors say.
The research has been published on the arxiv.org preprint server.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.