125318951
Selfdual vortices in curved space
15623742
Lorentz and CPT violating Chern-Simons term in the formulation of functional integral
We show that in the functional integral formalism the (finite) coefficient of the induced, Lorentz- and CPT-violating Chern-Simons term, arising from the Lorentz- and CPT-violating fermion sector, is undetermined.
30363280
NGC 3801 caught in the act: a post-merger star-forming early-type galaxy with AGN–jet feedback
In the current models of galaxy formation and evolution, AGN feedback is crucial to reproduce galaxy luminosity function, colour-magnitude relation and M• � relation. However, if AGN-feedback can indeed expel and heat up significant amount of cool molecular gas and consequently quench star formation, is yet to be demonstrated observationally. Only in four cases so far (Cen A, NGC 3801, NGC 6764 and Mrk 6), Xray observations have found evidences of jet-driven shocks heating the ISM. We chose the least-explored galaxy, NGC 3801, and present the first ultraviolet imaging and stellar population analysisis of this galaxy from GALEX data. We find this mergerremnant early-type galaxy to have an intriguing spiral-wisp of young star forming regions (age ranging from 100–500 Myr). Taking clues from dust/PAH, Hi and CO emission images we interpret NGC 3801 to have a kinamatically decoupled core or an extremely warped gas disk. From the HST data we also show evidence of ionised gas outflow similar to that observed in Hi and molecular gas (CO) data, which may have caused the decline of star formation leading to the red optical colour of the galaxy. However, from these panchromatic data we interpret that the expanding shock shells from the young (�2.4 million years) radio jets are yet to reach the outer gaseous regions of the galaxy. It seems, we observe this galaxy at a rare stage of its evolutionary sequence where post-merger star formation has already declined and new powerful jet feedback is about to affect the gaseous star forming outer disk within the next 10 Myr, to further transform it into a red-and-dead early-type galaxy.