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Full low resolution (65<R<130) and high resolution (R~600) spectra between 5microns and 37 microns obtained with the Infrared Spectrograph (IRS) on theSpitzer Space Telescope are presented for eight classical active galacticnuclei (AGN) which have been extensively studied previously. Spectra of theseAGN are presented as comparison standards for the many objects, includingsources at high redshift, which are being observed spectroscopically in themid-infrared for the first time using the IRS. The AGN are NGC4151, Markarian3, I Zwicky 1, NGC 1275, Centaurus A, NGC 7469, Markarian 231, and NGC 3079.These sources are used to demonstrate the range of infrared spectra encounteredin objects which have widely different classification criteria at otherwavelengths but which unquestionably contain AGN. Overall spectralcharacteristics - including continuum shape, nebular emission lines, silicateabsorption and emission features, and PAH emission features - are considered tounderstand how spectral classifications based on mid-infrared spectra relate tothose previously derived from optical spectra. The AGN are also compared to thesame parameters for starburst galaxies such as NGC 7714 and the compact, lowmetallicity starburst SBS 0335-052 previously observed with the IRS. Resultsconfirm the much lower strengths of PAH emission features in AGN, but there areno spectral parameters in this sample which unambiguously distinguish AGN andstarbursts based only on the slopes of the continuous spectra.Comment: Accepted by Ap

Mid‐Infrared Spectra of Classical AGNs Observed with theSpitzer Space Telescope