Search for intraday radio variability in EGRET blazars

ROMERO, G. E.; COMBI, J. A.; BENAGLIA, P.; AZCÁRATE, I. N.; CERSÓSIMO, J. C.; WILKES, L. M.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Año: 1997 vol. 326 p. 77 - 86

0004-6361

We present results of intraday variability observations at 5 GHz of the EGRET blazars 0202+14, 0235+16, 2230+11, and 2251+15. The BL-Lac object 0235+16 presented flux density variations of ~7% over timescales of ~1.3days. The source 0202+14 was also variable, although with smaller amplitudes. The behaviour of 0235+16 at short timescales is almost identical to that presented in previous intraday observations carried out in 1990, when the flux density of the source was 4 times higher. We discuss the possible origin of the ultra rapid radio variability in these sources within different possible scenarios.