Daily Image
22-10-2007
Radio jets and gas: they don't go well together
| Submitter: | Raffaella Morganti |
| Description: | In many radio sources, the effect of radio jets expanding in the surrounding gaseous medium can be disastrous. The gas can be blown away by the high-speed plasma of the jet. A dramatic example of this phenomenon has been observed in the southern Seyfert galaxy IC 5063. High-resolution and high-frequency (17 and 24 GHz) radio images were obtained with the Australia Telescope Compact Array ATCA (17 GHz shown in contours) while optical spectra of the ionised gas were obtained with EMMI on the ESO-NTT telescope at La Silla. The figure on top shows some of the many strong emission lines that are detected. The figure also shows the complex kinematics of the gas in the region co-spatial with the radio emission, while outside it the gas follows the gentle rotation of the galaxy. Broad and blueshifted emission is observed in the region of the radio lobe, indicating hot, ionised gas moving toward us at high speeds of about 500 km/s. Interestingly, at the same location, fast outflow of neutral hydrogen (with similar speeds) was observed already a few years ago with the ATCA. From this study we have learned that the mass outflow rate of the ionised gas is not large while that of the neutral gas is substantial and likely to have a significant impact on the evolution of the interstellar medium in the host galaxy. This study will soon appear in Astronomy & Astrophysics (Morganti, Holt, Saripalli, Oosterloo & Tadhunter 2007 http://arxiv.org/abs/0710.1189). |
| Copyright: | ASTRON |
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