|A PACS Spectroscopic Survey of the Chemistry of Transition Disks
|In the past decade, transition disks have emerged as the first possible, measurable signposts of planets that have already or are in the process of forming. Recent detections of planetary mass objects within the inner holes of two transition disks definitively link the presence of disk holes with planet formation. However, these transitional disks have so far not yet been studied much in the warm molecular gas of a few 100 K, which connects the cold bulk mass of the outer disk (probed in the sub-mm) with warm inner regions (probed in the near-IR). The structure of transition disks is typically measured from the shape of the spectral energy distribution or the spatially imaged dust. Although the gaseous disk can be more difficult to study, the structure and chemistry of gas will provide significant constraints on the prospects for the final abundances and continued growth of gas giant planets. Herschel PACS offers a unique possibility to study the mid-J to high-J lines of CO together with lines of OH and water. These lines are predicted to emerge from the inner few tens of AU. Here we propose a deep search for molecular emission in PACS spectra of 12 of the most exciting transitional disks, two of which are already approved for ALMA observations. These PACS observations provide diagnostic information on the structure and chemistry of the warm gas that is needed to constrain models of gas in transition disks and to understand the connections, if any, between the gas in the inner and outer disk.
|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_gherczeg_4, SPG v14.2.0. https://doi.org/10.5270/esa-2mg2jo0