|Probing The Unique Environment Around Sgr A*
|We propose to study the extreme conditions in the molecular gas surrounding Sgr A* by obtaining a full spectral survey of this source with Herschel-HIFI. This will provide a complete chemical inventory, containing multiple transitions spanning a broad range of excitation conditions, and will constitute a unique resource with which to explore the diverse physical processes at work and confront current models with important new constraints. The molecular gas in this circumnuclear disk also serves as a template for the study of central regions of other galaxies, helping to elucidate the properties in those distant sources. These data will also include absorption lines from many important hydrides in diffuse clouds along the line of sight, and we will also perform deep integrations at specific frequencies to target key metal hydrides, which will allow depletion, diffuse cloud chemistry and key chemical reactions to be probed. The plethora of emission and absorption lines that these observations will provide, across a frequency range that is largely inaccessible from the ground, will constitute a detailed chemical and physical portrait of the interstellar medium under a diverse and extreme range of conditions. As such, the proposed spectral survey and deep integrations represent a valuable legacy dataset for the future.
|High-velocity hot CO emission close to Sgr A*. Herschel-HIFI submillimeter spectral survey toward Sgr A* . Goicoechea J. R. et al. . Astronomy & Astrophysics, Volume 616, id.L1, 7 pp. . 616 . 10.1051/0004-6361/201833684 . 2018A&A...616L...1G ,
|Herschel was launched on 14 May 2009! It is the fourth 'cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
|Publisher And Registrant
|European Space Agency
|European Space Agency, 2013, OT1_tbell_2, SPG v14.1.0. https://doi.org/10.5270/esa-thi9p9n