Posted by P. LaViolette, February 8, 2016
A group of astronomers has observed an ultrafast wind of oxygen atoms blowing away from the active core of Seyfert galaxy IRAS17020+4544. The wind was observed to be moving away from the galaxy’s active core at a velocity of 23,000 to 33,000 km/s, or at about 10% of the speed of light. This galaxy is of particular interest because it has a shape similar to our own and a supermassive core of mass 5.9 X 10^6 solar masses, slightly more massive than our own Galactic core, Sgr A*. Ultrafast winds had previously been identified in more massive elliptical galaxies. This was the first time one has been found in a galaxy similar to our own. This provides further confirmation for the reality of superwaves, a theory first proposed 33 years ago (LaViolette, 1983). According to this theory these high velocity winds observed to exit from active nuclei would be driven by cosmic ray volleys propagating outward along radial trajectories.
Co-author Matteo Guainazzi states:
“Of course we cannot be sure, but our discovery implies that fast outflows like those found in IRAS17020+4544 may have once swept through our own Galaxy during one of these active phases… This possibility was not considered before, because this ‘feedback’ from X-ray winds was previously observed only in galaxies very different from the Milky Way.”
To correct Dr. Guainazzi’s misstatement, the possibility of fast outflows having swept through our Galaxy was indeed considered before back in 1983 based on a combination of Galactic, extragalactic, and geological evidence. The results of this recent study by A. L. Longinotti et al. only confirms the conclusions already reached 33 years ago.
Longinotti et al. report that the wind entails a total mass loss rate of between 0.01 and 1 solar masses per year and comprises a kinetic energy of between 10^42 to 10^45 ergs/s. By comparison in my 1983 study I had considered a Seyfert like cosmic ray outburst from the Milky Way’s core that had a luminosity of 10^48 ergs/s occurring about 12,000 to 14,000 years ago. Hence if these cosmic rays were to transfer about 10^-5 of their energy to the interstellar medium, wind luminosities similar to those seen in IRAS17020+4544 would could have occurred in the Milky Way. If anything, this finding of high velocity winds coming from active cores underlines the fact that active galactic cores are not black holes powered by matter accreted from their surroundings. Because with such a strong wind, no matter would succeed in falling into the core. Any nearby dust or cometary material would be vaporized and pushed outward.
A mass loss rate of 0.01 to 1 Msolar per year reported above is not that great when compared with the Milky Way’s core where in its current quiescent state a high velocity wind is seen to be carrying matter away at the rate of 0.02 to 0.03 solar masses per year.
For news about this finding consider these links:
But do not be misled by the diagrams they use to illustrate their articles. There is no evidence that this is just a polar wind. Observations of other galaxies indicate that these winds are isotropic and hence propagate through the galaxy’s disc as well.