Quasar ON471: WSRT and VLBI Observation, Radio Spectrum

1Volvach, AE, 1Nesterov, NS
1Laboratory of Radio Astronomy, SRI Crimean Astrophysical Observatory, Katsiveli, AR Crimea, Ukraine
Kosm. nauka tehnol. 2002, 8 ;(Supplement2):279-283
Publication Language: Russian
According to the observations of the quasar OH471 (z=3.4) at a frequency of 325 MHz in 1985–1996. detected variability of its radio emission. During this period, the flux density of radio emission increased 1.6 times. At a distance of 2.5 ′ to the north of the quasar, a radio source with a steep spectrum was selected. The flux density of its radio emission at a frequency of 5 GHz is 1.46 mJy, and at a frequency of 350 MHz – 14.5 mJy. According to the observations of 1964-1996. In the frequency range 0.325–90 GHz, the peculiarities of the variability of the OH 471 quasar were investigated. The spectrum had peaks at frequencies around 1 and 20 GHz. The flux density of the low-frequency component first decreased and then began to increase. The high-frequency component increased to 2.5 Jan in the late 1970s. The frequencies of the highs remained virtually unchanged. According to the results of VLBI observations at a frequency of 1.6 GHz, a structure of the type is obtained: the core is a jet 0.005 ″, oriented eastward. The object is one of the powerful quasars.
1. Carswell R. F., Strittmatter P. A. In: Nature, 242, 396 (1973).
2. Polatidis A. G., Wilkinson P. N., Xu W., Readhead A. C. S., et al. In: Astrophys. J. Suppl. Ser., 98, 1 (1995).
3. Efanov V. A., Moiseev I. G., Nesterov N. S., et al. Observations of radio sources with the RT-22 at CAO and the RT-14 at RHUT in the millimeter wavelength range. Izv. Krym. Astrofiz. Obs., 64, 103–108 (1981) [in Russian].
4. Boars J. W. M., Pauliny-Toth I. I. K., Witzel A. In: Astron. and Astrophys., 61, 99 (1977).
5. Riley J. M., Green D. A. In: Monthly Not. Roy Astron. Soc., 301, 203 (1998).
6. Minns A. R., Riley J. M. In: Monthly Not. Roy Astron. Soc., 315, 839 (2000).
7. Gubbay J., Legg A. J., Robertson D. S., et al. In: Astrophys. J., 215, 20 (1977).
8. Marscher A. P., Shaffer D. B. In: Astron. J., 85, 668 (1980).
9. Gurvits L. I., Kardashev N. S., Popov M. V., et al. In: Astron. Astrophys., 260, 82 (1992).
10. Bloom S. D., Marscher A. P., Moore E. M., et al. In: Astrophys. J. Suppl. Ser., 1, 1 (1999).
11. Xu W., Readhead C. S., Pearson T. J., et al. In: Astroph. J. Suppl. Ser., 99, 297 (1995).
12. Kellerman K. I., Vermeulen R. C., Zensus J. A., Cohen M. H. In: Astron. J., 115, 1295 (1998).

13. Fey A. L., Charlot P. In: Astroph. J. Suppl. Ser., 111, 95 (1997).