|Characterization of the long wavelength features of interstellar Polycyclic Aromatic Hydrocarbons
|Strong emission features at 3.3, 6.2, 7.7, and 11.2 um dominate the mid-infrared spectra of most interstellar objects. These IR features are due to vibrational fluorescence of large (50-150 C-atom) Polycyclic Aromatic Hydrocarbon molecules pumped by UV photons. These species will also have bands at far-infrared wavelength, notably due to .drum-head modes. We have performed experimental and theoretical studies that demonstrate that these bands carry unique information, particularly on the size of the emitting species that cannot be obtained from the shorter wavelength bands. We propose to measure the far-IR spectra of a sample of well-studied PAH sources using PACS and SPIRE. The sample has been carefully selected to show strong mid-IR PAH bands, and a relatively weak dust continuum at the Herschel wavelengths to maximize the line-to-continuum ratio for far-IR PAH bands. These observations are designed to measure infrared bands to a level of 1% of the dust continuum. Together with the Spitzer-ISO studies, the full spectrum of the IR emission features from 3 to 600 um can be determined. In order to determine the implications for the emitting PAHs, we will compare these bands to the PAH database that we have compiled over the last 15 years and analyze the emission using the realistic PAH emission model that we have developed over the years.
|The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder - II. Estimating radial velocity of SPIRE spectral observation sources . Scott Jeremy P. et al. . Monthly Notices of the Royal Astronomical Society . null . null . 2020MNRAS.496.4894S ,
Herschel PACS and SPIRE spectroscopy of the photodissociation regions associated with S 106 and IRAS 23133+6050 . Stock D. J. et al. . Astronomy & Astrophysics, Volume 579, id.A67, 19 pp. . 579 . 10.1051/0004-6361/201425245 . 2015A&A...579A..67S ,
The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder - III. Line identification and off-axis spectra . Benson Chris S. et al. . Monthly Notices of the Royal Astronomical Society . null . null . 2020MNRAS.496.4906B ,
The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder I. The Spectral Feature Finder and Catalogue . Hopwood R. et al. . Monthly Notices of the Royal Astronomical Society . null . null . 2020MNRAS.496.4874H ,
|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, 2012, OT1_epeeters_1, SPG v14.2.2. https://doi.org/10.5270/esa-xqphe64