Utilizing NASA’s Chandra X-ray Observatory, a team of astronomers has realized deep imaging observations of a high-redshift radio galaxy dubbed 4C 63.20. The research has unveiled an extended X-ray emission from the source.
Radio galaxies transmit huge amounts of radio waves from their cores. Black holes at the centers of these galaxies accrete dust and gas, producing high-energy streams noticeable in radio wavelengths, that accelerate electrically charged particles to high speeds. Here is what you need to know.
New Research Investigates X-ray Emission
A team of astronomers led by researcher Kate Napier of the University of Michigan examined a new X-ray source using the Advanced CCD Imaging Spectrometer (ACIS), an X-ray imager aboard Chandra.
The Chandra observations indicate that the X-ray counterpart to 4C 63.20 is made of a compressed core plus extended southeast-to-northwest ejection. This prolonged X-ray emission estimates for almost 30 % of the flux and turned out to be aligned with the radio hotspots of 4C 63.20 spotted at 5.0 GHz.
The astronomers observed that although the perceived separation and centroid positions of the two X-ray sources point to a diffuse (lobe-like origin), the scenario that they are two compact hotspots can’t be ruled out at the moment.
Trying to reproduce the SED (spectral energy distribution) of the 4C 63.20 system, the team discovered that it could be defined by a jet model attributing the majority of the radio flux to synchrotron emission from the hotspots. If it’s about the X-ray emission, it can be produced via IC (inverse Compton) scattering off the disc, CMB (cosmic microwave background), and torus.
“This scenario […] supports the view that IC/CMB may quench less extreme radio loves at high redshift,” explained the astronomers.
Summing up the findings, the team concluded that the case of 4C 63.20 indicates that HzRGs are not radio-quenched. The X-ray luminosities of these sources, however, are consistent with the expectation from highly magnetized lobes in a warmer CMB.