RADIO PHYSICS AND RADIO ASTRONOMY

Purpose: Estimate of the environment density of giant (with the linear size of about megaparsec) radio structures for galaxies and quasars with steep low-frequency spectra taken from the UTR-2 catalogue. Study of the cosmological evolution of environment density of giant radio sources. Determination of dependence of contribution of radio lobes into the emission of giant sources with respect to their environment density.

Design/methodology/approach: We use the sample of sources from the UTR-2 catalogue of extragalactic sources to estimate the environment density for giant sources with steep low-frequency spectra. The selection criteria for the examined objects are the following: 1) the spectral index value is equal or larger than 1; 2) the fl ux density of emission at the frequency of 25 MHz is larger than 10 Jy; 3) the sample sources are optically identifi ed. The value of environment density of examined sources is obtained with the assumption of equality of source jet luminosity (at the synchrotron mechanism of radio emission) and its corresponding kinetic luminosity. The analysis of the estimates of environment densities is made for different classes of the sample objects (for galaxies and quasars with linear steep spectra and with break steep spectra).

Findings: The estimates of environment density have been derived for giant radio structures formed by the jets of sources with steep spectrum from the UTR-2 catalogue. On the average, the environment density for the quasar structure (~ 10^-28 g/sm³) is lesser than the one for the galaxies (~ 10^-27 g/sm³ to ~ 10^-26 g/sm³). The larger jet environment density is typical for the galaxies and quasars with the break steep spectra than for those with the linear steep spectra. The inverse power relation of the jet environment density and the source redshift (the cosmological evolution of the jet environment density) has been derived. The contribution of jet-related radio lobes into the emission of sources displays the inverse power relation for the environment density of the corresponding radio structures.

Conclusions: The mean values of obtained estimates of environment density of giant jets of radio sources with steep low-frequency spectra indicate the lesser environment density of quasar jets than that for the galaxy jets. Giant radio sources with steep low-frequency spectrum (especially, with break steep spectrum) reveal considerable evolution of environment density of jets. The larger contribution of radio lobes (jets) into the emission of sources corresponds to the lesser environment density of sources taken from the UTR-2 catalogue. It can be due to propagation of jets (surrounded by radio lobes) from powerful radio sources to distances of about megaparsec, until the balance of source’s environment density and extragalactic environment density is reached.

Key words: steep low-frequency radio spectrum; giant radio structure; jets; radio lobes; galaxies; quasars; environment density

Manuscript submitted 01.02.2021

Radio phys. radio astron. 2021, 26(2): 165-172

REFERENCES

1. BRAUDE, S. YA., MEGN, A. V., RASHKOVSKI, S. L., RYABOV, B. P., SHARYKIN, N. K., SOKOLOV, K. P., TKACHENKO, A. P. and ZHOUCK, I. N., 1978. Decametric survey of discrete sources in the Northern sky. II. Source catalogue in the range of declinations +10^o to +20^o. Astrophys. Space Sci. vol. 54, is. 1, pp. 37–128. DOI: https://doi.org/10.1007/BF00637903

2. BRAUDE, S. YA., MEGN, A. V., SOKOLOV, K. P., TKACHENKO, A. P. and SHARYKIN, N. K., 1979. Decametric survey of discrete sources in the northern sky. V. Source catalogue in the range of declinations 0^o to +10^o. Astrophys. Space Sci. vol. 64, is. 1, pp. 73–126. DOI: https://doi.org/10.1007/BF00640035

3. BRAUDE, S. YA., MIROSHNICHENKO, A. P., SOKOLOV, K. P. and SHARYKIN, N. K., 1981. Decametric survey of discrete sources. VII. Source catalogue in the range of declinations –2^o to –13^o. Astrophys. Space Sci. vol. 74, is. 2, pp. 409–451. DOI: https://doi.org/10.1007/BF00656446

4. BRAUDE, S. YA., MIROSHNICHENKO, A. P., SOKOLOV, K. P. and SHARYKIN, N. K., 1981. Decametric survey of discrete sources. VIII. Spectra of discrete sources in the range 12.6 to 1400 MHz for declinations –2^o to –13^o. Astrophys. Space Sci. vol. 76, is. 2, pp. 279–299. DOI: https://doi.org/10.1007/BF00687495

5. BRAUDE, S. YA., MIROSHNICHENKO, A. P., RASHKOVSKII, S. L., SIDORCHUK, K. M., SIDORCHUK, M. A. and SHARYKIN, N. K., 2003. Decametric survey of discrete sources in the Northern sky. XIIIb. Spectra of discrete sources in the declination zone from +30° to +40°. Kinematika i Fizika Nebesnykh Tel. vol. 19, no. 4, pp. 291–306. (in Russian).

6. KONOVALENKO, A., SODIN, L., ZAKHARENKO, V., ZARKA, P., ULYANOV, O., SIDORCHUK, M., STEPKIN, S., TOKARSKY, P., MELNIK, V., KALINICHENKO, N., STANISLAVSKY, A., KOLIADIN, V., SHEPELEV, V., DOROVSKYY, V., RYABOV, V., KOVAL, A., BUBNOV, I., YERIN, S., GRIDIN, A., KULISHENKO, V., REZNICHENKO, A., BORTSOV, V., LISACHENKO, V., REZNIK, A., KVASOV, G., MUKHA, D., LITVINENKO, G., KHRISTENKO, A., SHEVCHENKO, V. V., SHEVCHENKO, V. A., BELOV, A., RUDAVIN, E., VASYLIEVA, I., MIROSHNICHENKO, A., VASILENKO, N., OLYAK, M., MYLOSTNA, K., SKORYK, A., SHEVTSOVA, A., PLAKHOV, M., KRAVTSOV, I., VOLVACH, Y., LYTVINENKO, O., SCHEVCHUK, N., ZHOUK, I., BOVKUN, V., ANTONOV, A., VAVRIV, D., VINOGRADOV, V., KOZHIN, R., KRAVTSOV, A., BULAKH, E., KUZIN, A., VASILYEV, A., BRAZHENKO, A., VASHCHISHIN, R., PYLAEV, O., KOSHOVYY, V., LOZINSKY, A., IVANTYSHIN, O., RUCKER, H. O., PANCHENKO, M., FISCHER, G., LECACHEUX, A., DENIS, L., COFFRE, A., GRIEßMEIER, J.-M., TAGGER, M., GIRARD, J., CHARRIER, D., BRIAND, C. and MANN, G., 2016. The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT. Exp. Astron. vol. 42, is. 1, pp. 11–48. DOI: https://doi.org/10.1007/s10686-016-9498-x

7. MIROSHNICHENKO, A. P., 2010. Luminosity and space distributions of radio sources with steep spectra at the decameter band. In: S. K. CHAKRABARTI, A. I. ZHUK and G. S. BISNOVATYI-KOGAN, eds. Astrophysics and Cosmology after Gamow. AIP Conference Proceedings. Vol. 1206. New York: AIPC, pp. 335–345. DOI: https://doi.org/10.1063/1.3292538

8. MIROSHNICHENKO, A. P., 2012. Physical parameters of radio sources with steeply rising decameter wavelength spectra. Radio Phys. Radio Astron. vol. 3, is. 3, pp. 215–221. DOI: https://doi.org/10.1615/RadioPhysicsRadioAstronomy.v3.i3.40

9. MIROSHNICHENKO, A. P., 2013. The timing scale of the steep-spectrum sources. Odessa Astronomical Publications. vol. 26, is. 2, pp. 248–250.

10. MIROSHNICHENKO, A. P., 2015. Luminosity-linear size relation for galaxies and quasars with steep radio spectrum. Odessa Astronomical Publications. vol. 28, is. 2, pp. 238–241. DOI: https://doi.org/10.18524/1810-4215.2015.28.71032

11. MIROSHNICHENKO, A. P., 2019. Jet propagation velocity and environmental density of giant radio sources with steep radio spectrum. Astrophys. Space Sci. vol. 364, is. 5, id. 92. DOI: 10.1007/s10509-019-3580-6

12. DALY, R. A., 1995. Powerful extended radio sources as tools to estimate ambient gas densities, jet luminosities, and other key physical parameters. Astrophys. J. vol. 454, pp. 580–592. DOI: https://doi.org/10.1086/176511

13. KLEIN, U., MACK, K.-H. and SARIPALLI, L., 1996. General properties of giant radio galaxies. In: R. EKERS, C. FANTI, and L. PADRIELLI, eds. Extragalactic Radio Sources. International Astronomical Union, vol 175. Dordrecht: Kluwer Academic Publ., pp. 311–312. DOI: https://doi.org/10.1007/978-94-009-0295-4_109

14. MACK, K.-H., KLEIN, U., O’DEA, C. P., WILLIS, A. G. and SARIPALLI, L., 1998. Spectral indices, particle ages, and the ambient medium of giant radio galaxies. Astron. Astrophys. vol. 329, pp. 431–442.

15. SHOENMAKERS, A. P., MACK, K.-H., DE BRUYN, A. G., RÖTTGERING, H. J. A., KLEIN, U. and VAN DER LAAN, H., 2000. A new sample of giant radio galaxies from the WENSS survey. II. A multifrequency radio study of a complete sample: properties of the radio lobes and their environment. Astron. Astrophys. Suppl. Ser. vol. 146, no. 2, pp. 293–322. DOI: https://doi.org/10.1051/aas:2000267

16. MACHALSKI, J., CHYZY, K. and JAMROZY, M., 2004. Giant radio sources in view of the dynamical evolution of FRII-type population. I. Observational data and basic physical parameters of sources derived from the analytical model. Acta Astron. vol. 54, pp. 249–279.

17. LACY, M., RAWLINGS, S., SAUNDERS, R. and WARNER, P. J., 1993. 8C 0821+695: a giant radio galaxy at z=0.538. Mon. Not. R. Astron. Soc. vol. 264, is. 3, pp. 721–728. DOI: https://doi.org/10.1093/mnras/264.3.721

18. LEAHY, J., 1991. Interpretation of large scale extragalactic jets. In: P. HUGHES, ed. Beams and Jets in Astrophysics. Cambridge: Cambridge University Press, pp. 100–186. DOI: https://doi.org/10.1017/CBO9780511564703.004

19. MACHALSKI, J., KOZIEŁ-WIERZBOWSKA, D., JAMROZY, M. and SAIKIA, D. J., 2008. J1420–0545: The radio galaxy larger than 3C 236. Astrophys. J. vol. 679, no. 1, pp. 149–155. DOI: https://doi.org/10.1086/586703

20. O’DEA, C. P., DALY, R. A., KHARB, P., FREEMAN, K. A. and BAUM, S. A., 2009. Physical properties of very powerful FRII radio galaxies. Astron. Astrophys. vol. 494, no. 2, pp. 471–488. DOI: https://doi.org/10.1051/0004-6361:200809416

21. HUNIK, D. and JAMROZY, M., 2016. Discovery of ultra-steep spectrum giant radio galaxy with recurrent radio jet activity in Abell 449. Astrophys. J. Lett. vol. 817, no. 1, id. L1. DOI: https://doi.org/10.3847/2041-8205/817/1/L1