Reassessment of an Origin of the Radio Structure of J1420–0545 (original) (raw)

Intermittent jet activity in the radio galaxy 4C�29.30

Monthly Notices of The Royal Astronomical Society, 2007

We present radio observations at frequencies ranging from 240 to 8460 MHz of the radio galaxy 4C 29.30 (J0840+2949) using the Giant Metrewave Radio Telescope (GMRT), the Very Large Array (VLA) and the Effelsberg telescope. We report the existence of weak extended emission with an angular size of ∼520 arcsec (639 kpc) within which a compact edge-brightened double-lobed source with a size of 29 arcsec (36 kpc) is embedded. We determine the spectrum of the inner double from 240 to 8460 MHz and show that it has a single power-law spectrum with a spectral index of ∼0.8. Its spectral age is estimated to be ≲33 Myr. The extended diffuse emission has a steep spectrum with a spectral index of ∼1.3 and a break frequency ≲240 MHz. The spectral age is ≳200 Myr, suggesting that the extended diffuse emission is due to an earlier cycle of activity. We re-analyse archival X-ray data from Chandra and suggest that the X-ray emission from the hotspots consists of a mixture of non-thermal and thermal components, the latter being possibly due to gas which is shock heated by the jets from the host galaxy.

Radio Observation of J 1035-201 , J 1045-294 and J 1046-293

2005

Radio observations of J1035-201, J1045-294, and J1046-293 were taken in order to characterize their structure on the parsec scale relative to their structure on the kiloparsec scale. All three sources were found to have jets on the kiloparsec scale, while only two exhibited this feature on the parsec scale. For each source, the peak core flux density at the kiloparsec scale was determined to originate almost entirely from a single pointlike source at the parsec scale. The possibility that these sources are black holes was explored and the characteristics of these potential black holes were approximated. Introduction Intense, pointlike radio sources, often accompanied by jets, have been found to exist at the center of some galaxies. These sources are known as quasars. It is hypothesized that these radio sources are supermassive black holes. The intense radio emission is thought to be radiated by matter falling into the black hole from a rapidly spinning accretion disk surrounding the...

Revealing the unusual structure of the KAT-7-discovered giant radio galaxy J0133−1302

Monthly Notices of the Royal Astronomical Society, 2021

We present a new study of the 1.7 Mpc KAT-7-discovered giant radio galaxy, J0133−1302, which was carried out using GMRT data at 323 and 608 MHz. This source is located at RA 01h33m13s and Dec −13○03′00″ and has a photometric redshift of ∼0.3. We discovered unusual morphological properties of the source which include lobes that are exceptionally asymmetric, where the upper lobe is much further from the core when compared to the lower lobe, and a complex structure of the upper lobe. The complex structure of the upper lobe hints at the presence of another source, in close proximity to the edge of the lobe, which resembles a bent-double, or distorted bent tail (DBT) radio galaxy. Both the upper lobe and the lower lobe have a steep spectrum, and the synchrotron age of the lower lobe should be less than about 44 Myr. The core has an inverted spectrum, and our results suggest that the parent galaxy in J0133−1302 is starting a new jet activity. Our spectral analysis indicates that this sour...