16 (mu)m Imaging around the Hubble Deep Field-North with the Spitzer IRS

We present a pilot study of 16 (mu)m imaging within the GOODS northern field. Observations were obtained using the "peak-up" imaging capability of the Spitzer IRS. We survey 35 arcmin2 to an average 3 (sigma)depth of 0.075 mJy and detect 149 sources. The survey partially overlaps the area imaged at 15 (mu)m by the ISO, and we demonstrate that our photometry and galaxy number counts are consistent with its measurements. We infer the total infrared luminosity of 16 (mu) m detections using a comparison to local templates and find a wide range of LIR, from ~109 to 1012 L(circled dot operator). Approximately 1/5 of the detected sources have counterparts in the Chandra 2 Ms catalog, and we show that the hard-band (2-8 keV) detected sources are likely to have strong active galactic nucleus (AGN) contributions to the X-ray flux. The ultradeep sensitivity of Chandra implies that some X-ray detections may be purely starbursting objects. We examine the 16 to 24 (mu)m flux ratio and conclude that it shows evidence for the detection of redshifted polycyclic aromatic hydrocarbon (PAH) emission at z ~0.5 and z > 0.8.