| Description |
We will investigate the inflow of matter in the bulge of the Milky Way using the HIFI and PACS instruments on Herschel to observe [C II], [N II], [O I], [O III], and high-J CO emission lines to determine the relationship between central black holes and their host galactic bulges and thus the causes and mechanisms of starbursts. As Binney et al. (1991) have suggested, the gas in closed orbits in the bar of the Milky Way provides a means to study in detail the accretion processes leading to starbursts and active galactic nuclei. Shocks effectively transfer some fraction of the clouds. orbital kinetic energy into heat which escapes through dust continuum and line emission. By measuring this emission and characterizing the star formation that occurs under these unusual conditions, we can estimate the amount of orbital energy that has been dissipated and constrain estimates of the mass inflow from the decaying orbits. For this purpose high velocity resolution observations of interstellar cooling lines are required. In the following proposal we discuss how HIFI and PACS observations of [C II], [N II], [O I], [O III], and high-J CO lines can be combined with existing radio emission line surveys and far-infrared continuum surveys to identify and estimate the energy loss and resulting infall motions from clumps in the inner galaxy. Using existing submillimeter-wave spectral line surveys, we are able to identify those regions lying between 2 kpc and 200 pc of the Galactic center that are emitting significant terahertz line radiation, and we can therefore accomplish a comprehensive characterization of gas in the inner galaxy using pointed Herschel observations. As ALMA comes online, we will be able to use the understanding produced by this study to understand the gas dynamics of other galaxies and properly place them in context. |
