|Polycyclic aromatic hydrocarbons (PAHs) in protoplanetary disks around late-type T Tau stars in Orion Nebular Cluster
|kim, k. h.
|We propose a search for far-infrared features from polycyclic aromatic hydrocarbon molecules (PAHs) in a small sample of protoplanetary disks around late-type T Tau stars. These objects were identified in the course of our large Spitzer-IRS survey of the Orion A cloud to have mid-infrared PAH features with unusual profiles, which are far too bright to explain by photoexcitation by their host stars; they must be excited by ultraviolet light from their more massive neighbors. Recent laboratory spectra of PAHs demonstrate the variation of wavelength and strength with molecule size for the far-infrared features of PAHs, a sensitivity that is lacking in the mid-infrared features. The observation of such features in disks around low-mass stars, in which we frequently see the effects of coagulation and growth among the silicate-grain population, represents an opportunity to search for size variation among the PAH population, a congruence with the PAH molecules found in the primitive meteorites, and perhaps hints of the role played by carbonaceous molecules in the assembly of solid bodies in disks.
|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_kkim_1, SPG v14.2.2. https://doi.org/10.5270/esa-af5myv4