Astronomers conclude that star formation in galaxies ceases during a less luminous period of active galactic nucleus (AGN) activity.
Can we conclude that the most luminous phase of AGN activity is in fact destroying the host galaxy, dissipating the surrounding stars and leaving behind only the active core?
I believe that the strong IR emission seen coming from this interacting galaxy II Zw 096 may be an example where the original host galaxy located in the center of this cluster, the bright red region, has been dissipated, and only the core remains.
Response to your post:
No, I very much doubt that an AGN would destroy its host galaxy. The above article about star formation and AGN’s is misleading. It assumes that stars form only through accretion of dust from their surroundings and that this accretion process results in excess infrared emission. In subquantum kinetics, on the other hand, the main mechanism for star formation is through continuous matter creation in the star’s interior, especially so in the more massive stars.
When astronomers refer to star forming regions they are referring to regions of excessive infrared radiation emission coming from dusty regions near stars. I believe that this infrared emission is instead being produced by the superwave cosmic rays that were emitted by a formerly active core. As this superwave cosmic ray shell travels away from the core, it vaporizes frozen ice and cometary material orbiting in the vicinity of a star and blows the resulting nebular material in close to the star where it aggravates the star into a flaring T Tauri state. This usually happens when the superwave has advanced outward from the core’s immediate vicinity and encounters dusty regions in the galaxy’s spiral arms. By that time, the AGN will have completed its active phase and entered its quiescent phase. So galactic core emission will no longer be visible, when excessive infrared emission is visible. This assumes that the core of a typical spiral galaxy spends about 15% of its time in its active phase, a period lasting several hundred to several thousand years.
Regarding the point you made about the interacting galaxy II Zw 096, sometimes called the “galactic train-wreck”, I doubt that we can conclude that this infrared emission comes from a bare galactic core. Astronomers find that 80% of the emission from this galaxy comes from this region which spans about 700 light years. We need more information before we may conclude that this IR region might harbor an ejected active core fragment.
November 2011, updated February 2013