Estimating the Ages of Bars: Implications for the Bar-AGN-Star Formation Connection
نویسنده
چکیده
In an effort to elevate to higher grounds our understanding on the impact of the formation and evolution of bars in the formation and evolution of galaxies, we have developed a diagnostic tool to distinguish between recently formed and evolved bars. Our method was applied in the study of a sample of 14 galaxies and revealed that, apparently, AGN activity tends to appear in galaxies which have young bars rather than evolved bars. This suggests that the time scale for the fueling of AGN by bars is short, and may help to explain, for instance, why there is not a clear correlation between the presence of bars and AGN in galaxies.
منابع مشابه
Bar strength and star formation activity in late-type barred galaxies
With the prime aim of better probing and understanding the intimate link between star formation activity and the presence of bars, a representative sample of 32 non-interacting late-type galaxies with well-determined bar properties has been selected. We show that all the galaxies displaying the highest current star forming activity have both strong and long bars. Conversely not all strong and l...
متن کاملThe AGN-Disk Dynamics Connection
Any connection between central activity and the large-scale dynamics of disk galaxies requires an efficient mechanism to remove angular momentum from the orbiting material. The only viable means of achieving inflow from kiloparsec scales is through gravitational stresses created by bars and/or mergers. The inflow of gas in bars today appears to stall at a radius of few hundred parsec, however, ...
متن کاملThe Influence of Bars on Nuclear Activity
Gravitational torques induced by a stellar bar on the interstellar medium of a disk galaxy instigate radial inflow of gas toward the central regions of the galaxy. Accordingly, the presence of a bar should reinforce nuclear star formation activity or the fueling of an active galactic nucleus (AGN). We test this hypothesis by comparing the detection rate and intensity of nuclear H II regions and...
متن کاملThe Starburst-AGN connection: Implications for the Unification of Seyferts
Observations at ultraviolet, optical and near-infrared wavelengths have shown the existence of recent star formation in the nuclear regions of Seyfert 2 (Sy2) galaxies that suggest a connection between the Starburst and the Seyfert phenomenon. According with the standard unified models of AGN circumnuclear starbursts also have to be present (and in the same numbers) in Sy1 as in Sy2 galaxies. T...
متن کاملDynamical Decoupling of Nested Bars: Self-gravitating Gaseous Nuclear Bars
A substantial fraction of barred galaxies host additional nuclear bars which tumble with pattern speeds exceeding those of the large-scale (primary) stellar bars. We have investigated the mechanism of formation and dynamical decoupling in such nested bars which include gaseous (secondary) nuclear bars within the full size galactic disks, hosting a double inner Lindblad resonance. Becoming incre...
متن کامل