Abstract
We present here the discovery of rapid, large amplitude intraday
variability in the compact flat-spectrum radio quasar 1156+295. The
detection of 40% flux density variations at 15 GHz on a timescale of
only 2.7 hours was serendipitously made when the source was observed
with the Very Long Baseline Array as a part of the MOJAVE survey
programme on February 5, 2007. Intraday variability on timescales of a
few hours or less is rare, and there exist very few sources that show
large-amplitude variations on a timescale as short as what is now
observed for 1156+295. The shape of the visibility function of the
source changes very little during the observation, although the
correlated flux density changes by 40%. This suggests that the
variability occurs in a single dominant compact component. The observed
variability characteristics are consistent with interstellar
scintillation in nearby, highly turbulent medium. The rms amplitude of
modulation at 15 GHz is unusually large and it implies a rather high
scattering measure along the line-of-sight towards 1156+295.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the Workshop on Blazar Variability across the Electromagnetic Spectrum. April 22-25, 2008 Palaiseau, France. Proceedings of Science |
| Pages | 62 |
| Volume | PoS(BLAZARS2008) |
| Publication status | Published - 2008 |
| MoE publication type | B3 Non-refereed conference publication |