A small subclass of radio galaxies, exhibiting a pair of secondary low-surface-brightness radio lobes oriented at an angle to the primary high-surface-brightness lobes, is the group known as X-shaped radio galaxies (XRGs). In some cases, it is seen that less luminous secondary lobes emerge from the edges of the primary high-brightness lobes, giving a Z-symmetric morphology. These objects are known as Z-shaped radio galaxies (ZRGs). From the Tata Institute of Fundamental Research (TIFR) Giant Metrewave Radio Telescope (GMRT) Sky Survey at 150 MHz, we present systematic search results for XRGs and ZRGs. We identified a total of 58 radio sources, out of which 40 are XRGs and 18 are ZRGs. Taking advantage of the large sample size of XRGs and ZRGs reported in the current work, different properties of XRGs and ZRGs are studied. Out of 58 XRGs and ZRGs presented here, 19 (32 per cent) are FR I and 33 (57 per cent) are FR II radio galaxies. For four XRGs and three ZRGs, the morphology is so complex that they could not be classified. We have estimated the radio luminosity and spectral index of newly discovered winged radio galaxies and made a comparative study with previously detected XRGs and ZRGs. Most of the XRGs show a steep spectral index between 150 and 1400 MHz and only 14 per cent of the sources show a flat spectrum, but for ZRGs a good proportion of the sources (36 per cent) show a flat spectrum.
Hybrid Morphology Radio Sources (HyMoRS) are a very rare subclass of radio galaxies with apparent mixed FR morphology, i.e. these galaxies seem to have an FR-I structure on one side of the core and an FR-II structure on the other side of the core. We systematically searched for HyMoRS using Very Large Array (VLA) Faint Images of the Radio Sky at Twenty-cm (FIRST) survey with 1400 MHz frequency and identified 33 candidate HyMoRS. Our finding significantly increased the known sample size of HyMoRS. HyMoRS may play an essential role in understanding the interaction of jets with the interstellar medium and the much-debated topic of the FR dichotomy. We identified optical counterparts for 29 sources in our catalogue. In our sample of sources, one source (J1106+1355) had quasar-like behaviour. Four sources were BRCLG (Brightest Cluster Galaxies) and six were LRG (Luminous Red Galaxies). We have estimated the spectral index and radio luminosity of HyMoRS in our catalogue, when possible. We found that J1136–0328 was the most luminous source in our sample (log L = 27.01 W Hz−1sr−1). It was also the farthest HyMoRS (with a redshift z = 0.82) in our sample. With the help of a large sample size of discovered sources, various statistical properties of detected galaxies were studied.
more » « less- NSF-PAR ID:
- 10368620
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 514
- Issue:
- 3
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- p. 4290-4299
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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