Australian astronomers detected a mystery bright and compact radio source known as J054149.24–641813.7 while doing radio continuum measurements of the spiral galaxy NGC 2082. This source’s origin and nature are unknown, and more research is needed. The discovery is detailed in a paper published on the arXiv pre-print site on May 23.
Radio sources are various objects in the universe that emit large amounts of radio waves in general. Pulsars, certain nebulas, quasars, and radio galaxies are among the most powerful sources of such emission.
A group of astronomers led by Joel Balzan of Western Sydney University in Australia has discovered a new radio source, the nature of which is still unknown. They discovered a powerful point radio source 20 arcseconds from the galaxy center while observing NGC 2082 with the Australian Square Kilometer Array Pathfinder (ASKAP), Australia Telescope Compact Array (ATCA), and Parkes radio telescope. NGC 2082 is a G-type spiral galaxy in the Dorado constellation, 60 million light years away from Earth and measuring 33,000 light years in diameter.
“From 888 MHz to 9,000 MHz, radio continuum observations of NGC 2082 were made using the ASKAP, ATCA, and Parkes telescopes. We detected a bright and compact radio source, J054149.24–641813.7, about 20 arcsec from the centre of this neighbouring spiral galaxy “The findings were published in a study by the researchers.
The radio luminosity of J054149.24–641813.7 at 888 MHz is 129 EW/Hz, according to the analysis, and it has a flat radio spectral index (about 0.02). This, the astronomers claim, rules out the possibility that J054149.24–641813.7 is a supernova remnant (SNR) or a pulsar, implying that the source is of thermal origin.
The compact nature of J054149.24–641813.7, as well as its location on the fringes of NGC 2082, reminded the researchers of several quick radio bursts (FRBs). The findings show, however, that J054149.24–641813.7 is unlikely to represent a persistent radio source with an embedded FRB progenitor.
J054149.24–641813.7 is most likely an extragalactic background source, such as a quasi-stellar object (QSO, quasar), radio galaxy, or active galactic nucleus, according to the researchers (AGN). They went on to say that the flat spectral index and weak polarisation between 5,500 and 9,000 MHz corroborate their theory. However, there is currently no high-resolution neutral atomic hydrogen (HI) absorption data for NGC 2082 to support this theory.
The authors of the research noted, “We find that the chance of detecting such a source behind NGC 2082 is P = 1.2 percent, and infer that the most likely origin for J054149.24–641813.7 is a background quasar or radio galaxy.”
