The Galactic Center as a pradigm for low-luminosity nuclei? What can be learned from SgrA* for the central engine and conditions of star formation in nuclei of Seyfert galaxies and low luminosity nearby QSOs; The K-band identification of the DSO/G2 source

Eckart, Andreas; Britzen, S.; Horrobin, M.; Zamaninasab, M.; Muzic, K.; Sabha, N.; Shahzamanian, B.; Yazici, S.; Moser, L.; Zuther, J.; Garcia-Marin, M.; Valencia-S., M.; Bursa, M.; Karssen, G.; Karas, V.; Jalali, B.; Vitale, M.; Bremer, M.; Fischer, S.; Smajic, S.; Rauch, C.; Kunneriath, D.; Moultaka, J.; Straubmeier, C.; Rashed, Y. E.; Iserlohe, C.; Busch, G.; Markakis, K.; Borkar, A.; Zensus, A.
Proceedings of Nuclei of Seyfert galaxies and QSOs - Central engine & conditions of star formation (Seyfert 2012). 6-8 November, 2012. Max-Planck-Insitut für Radioastronomie (MPIfR), Bonn, Germany. Online at, id.4 (2012).


The super-massive 4 million solar mass black hole (SMBH) SgrA* shows flare emission from the millimeter to the X-ray domain. The nucleus of the Milky Way has properties (stellar cluster, young stars, molecular gas and an accreting SMBH) that resemble those of currently higher luminous Low Luminosity Active Galactic Nuclei. A detailed analysis of the infrared light curves shows that the flares are probably generated in a single-state process forming a power-law distribution of the flux density. Near-infrared polarimetry shows signatures of strong gravity that are statistically significant against randomly polarized red noise. Details of the emission mechanism are discussed in a synchrotron/self-Compton model. SgrA* also allows to study the interaction of the SMBH with the immediate interstellar and gaseous environment of the central stellar cluster. Through infrared imaging of the central few arcseconds it is possible to study both inflow and outflow phenomena linked to the SgrA* black hole. In this context we also discuss the newly found dusty object that approaches SgrA* and present a comparison between recent Keck and VLT K-band data that clearly supports its detection as a about 19m K'-band continuum source.