PKS 0252−71

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Wikipedia

PKS 0251−71
The Radio galaxy PKS 0251−71
Observation data (J2000.0 epoch)
ConstellationHydrus
Right ascension02h 52m 46.15s[1]
Declination−71° 04′ 35.26″[1]
Redshift0.562880[1]
Heliocentric radial velocity168,747 km/s[1]
Distance5.636 Gly
Apparent magnitude (V)19.0
Characteristics
TypeNLRG[1]
Other designations
G4Jy 304, ICRF J025246.1−710435, LEDA 2823293, PAPER J042.83−71.00, PKS B0252−712, SUMSS J025246−710436[1]

PKS 0252−71 is a radio galaxy located in the southern constellation of Hydrus. The redshift of the object is (z) 0.562[1] and it was first discovered by astronomers as an astronomical radio source in 1977 whom they associated it with two objects.[2] Later in 1994, it was identified with a faint slightly resolved galaxy described to have emission lines in its spectrum.[3]

Description

PKS 0251−71 is classified as a narrow-line radio galaxy with a compact steep spectrum (CSS) source.[4][5] The emission lines in its optical spectrum are found mainly rich in ionized chemical element abundances.[6][7]

The radio source of PKS 0251−71 is found mainly compact with a symmetric structural appearance with the radio peaks having a separation gap of 145 milliarcseconds when imaged by Very Long Baseline Interferometry (VLBI). There are two resolved components containing 95% of the total flux density at 3.7 Jansky. There is absence of a radio core between the lobes.[8] A study published in 2014, has found its X-ray spectrum is mainly faint with two components; one jet-related with a bright appearance and some traces of absorption.[9]

The host galaxy of PKS 0251−71 is suggested to have an irregular halo structure surrounding it and also towards a companion galaxy that is located 33 kiloparsecs south from it. This suggest both galaxies are somehow interacting with each other.[10] There is also presence of outflows from the galaxy but it is mainly confined to the edges of its radio lobes with its outflow radius only being half of its radio source.[11]

References

  1. 1 2 3 4 5 6 7 "NED Search results for PKS 0252-71". NASA/IPAC Extragalactic Database. Retrieved 2025-12-13.
  2. ↑ Savage, A.; Bolton, J. G.; Wright, A. E. (April 1977). "Identification of southern radio sources - III". Monthly Notices of the Royal Astronomical Society. 179 (2): 135–141. doi:10.1093/mnras/179.2.135. ISSN 0035-8711.
  3. ↑ Alighieri, S. d. S.; Danziger, I. J.; Morganti, R.; Tadhunter, C. N. (1994-08-15). "New identifications and redshifts for southern 2-Jy radio sources" (PDF). Monthly Notices of the Royal Astronomical Society. 269 (4): 998–1010. doi:10.1093/mnras/269.4.998. ISSN 0035-8711.
  4. ↑ Morganti, R.; Oosterloo, T. A.; Reynolds, J. E.; Tadhunter, C. N.; Migenes, V. (January 1997). "A study of cores in a complete sample of radio sources". Monthly Notices of the Royal Astronomical Society. 284 (3): 541–551. doi:10.1093/mnras/284.3.541. ISSN 0035-8711.
  5. ↑ Tadhunter, C.; Dickson, R.; Morganti, R.; Robinson, T. G.; Wills, K.; Villar-Martin, M.; Hughes, M. (March 2002). "The origin of the UV excess in powerful radio galaxies: spectroscopy and polarimetry of a complete sample of intermediate-redshift radio galaxies". Monthly Notices of the Royal Astronomical Society. 330 (4): 977–996. arXiv:astro-ph/0201391. Bibcode:2002MNRAS.330..977T. doi:10.1046/j.1365-8711.2002.05153.x. ISSN 0035-8711.
  6. ↑ Morganti, R.; Tadhunter, C. N.; Dickson, R.; Shaw, M. (October 1997). "Clues on the nature of Compact Steep Spectrum radio sources from optical spectroscopy". Astronomy and Astrophysics. 326: 130–138. Bibcode:1997A&A...326..130M. ISSN 0004-6361.
  7. ↑ Tadhunter, C. N.; Morganti, R.; di Serego Alighieri, S.; Fosbury, R. a. E.; Danziger, I. J. (August 1993). "Optical spectroscopy of a complete sample of southern 2-Jy radio sources". Monthly Notices of the Royal Astronomical Society. 263 (4): 999–1022. Bibcode:1993MNRAS.263..999T. doi:10.1093/mnras/263.4.999. ISSN 0035-8711.
  8. ↑ Tzioumis, A.; King, E.; Morganti, R.; Dallacasa, D.; Tadhunter, C.; Fanti, C.; Reynolds, J.; Jauncey, D.; Preston, R.; McCulloch, P.; Tingay, S.; Edwards, P.; Costa, M.; Jones, D.; Lovell, J. (2002-09-01). "A sample of southern Compact Steep Spectrum radio sources: The VLBI observations" (PDF). Astronomy & Astrophysics. 392 (3): 841–850. arXiv:astro-ph/0207495. Bibcode:2002A&A...392..841T. doi:10.1051/0004-6361:20020964. ISSN 0004-6361.
  9. ↑ Mingo, B.; Hardcastle, M. J.; Croston, J. H.; Dicken, D.; Evans, D. A.; Morganti, R.; Tadhunter, C. (2014-03-08). "An X-ray survey of the 2 Jy sample – I. Is there an accretion mode dichotomy in radio-loud AGN?". Monthly Notices of the Royal Astronomical Society. 440 (1): 269–297. arXiv:1402.1770. doi:10.1093/mnras/stu263. ISSN 1365-2966.
  10. ↑ Ramos Almeida, C.; Tadhunter, C. N.; Inskip, K. J.; Morganti, R.; Holt, J.; Dicken, D. (October 2010). "The optical morphologies of the 2 Jy sample of radio galaxies: evidence for galaxy interactions". Monthly Notices of the Royal Astronomical Society: no. arXiv:1008.2683. doi:10.1111/j.1365-2966.2010.17542.x. ISSN 0035-8711.
  11. ↑ Santoro, F.; Tadhunter, C.; Baron, D.; Morganti, R.; Holt, J. (2020-12-01). "AGN-driven outflows and the AGN feedback efficiency in young radio galaxies". Astronomy & Astrophysics. 644: A54. arXiv:2009.11175. Bibcode:2020A&A...644A..54S. doi:10.1051/0004-6361/202039077. ISSN 0004-6361.