We present subarcsecond resolution mid infrared images of NGC 4151 at 10.8µm and 18.2µm. These images were taken with the University of Florida mid-IR camera/spectrometer OSCIR at the Gemini North 8 m telescope. We resolve emission at both 10.8µm and 18.2µm extending s 3.5′′ across at a P.A. of s 60◦. This coincides with the the narrow line region of NGC 4151 as observed in [OIII] by the Hubble Space Telescope. The most likely explanation for this extended mid-IR emission is dust in the narrow line region heated by a central engine. We find no extended emission associated with the proposed torus and place an upper limit on its mid-IR size of . 35 pc. (Refer to PDF file for exact formulas).

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Also archived in: arXiv:astro-ph/0212307 v1 12 Dec 2002 We would like to thank the Florida Space Grant Consortium for funding which led to the completion of this work as well as engineer Chris Carter who provided invaluable support while these observations were taken at Gemini North.ISSN:1538-4357 Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.

Document Type


Department, Program, or Center

School of Physics and Astronomy (COS)


RIT – Main Campus