|Probing the gas in the outer Galaxy: Molecular or Atomic?
|Despite of all theoretical speculations and various observational constraints, the nature of the dark matter in the outer Galaxy is still unknown. Herschel-HIFI offers the unique opportunity to detect or set a significant upper limit to a potential component of baryonic matter in the form of cold gas, which is molecular in hydrogen, but does not form CO. Such gas can be potentially be traced through [CII] 150 um and HF J=1-0 absorption against continuum background sources. We propose a set of 7 the brightest outer Galaxy dust continuum sources, for which we will determine the positions of peak emission by PACS mapping. Deep integrations in [CII] and HF towards the 4 brightest peaks in these sources will potentially detect a cold gas component and will, in any case, give significant upper limits to its column density.
|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, OT2_jstutzki_3, SPG v14.2.0. https://doi.org/10.5270/esa-nwevgwj