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Title: A MULTI-WAVELENGTH ANALYSIS OF NGC 4178: A BULGELESS GALAXY WITH AN ACTIVE GALACTIC NUCLEUS

We present Gemini longslit optical spectroscopy and Very Large Array radio observations of the nuclear region of NGC 4178, a late-type bulgeless disk galaxy recently confirmed to host an active galactic nucleus (AGN) through infrared and X-ray observations. Our observations reveal that the dynamical center of the galaxy is coincident with the location of the Chandra X-ray point source discovered in a previous work, providing further support for the presence of an AGN. While the X-ray and IR observations provide robust evidence for an AGN, the optical spectrum shows no evidence for the AGN, underscoring the need for the penetrative power of mid-IR and X-ray observations in finding buried or weak AGNs in this class of galaxy. Finally, the upper limit to the radio flux, together with our previous X-ray and IR results, is consistent with the scenario in which NGC 4178 harbors a deeply buried AGN accreting at a high rate.
Authors:
; ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Department of Physics and Astronomy, George Mason University, MS 3F3, 4400 University Drive, Fairfax, VA 22030 (United States)
  2. Department of Physics and Astronomy, Johns Hopkins University, 366 Bloomberg Center, 3400 N. Charles Street, Baltimore, MD 21218 (United States)
  3. Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States)
  4. INAF Istituto di Radioastronomia, I-40129 Bologna (Italy)
  5. NOAO Gemini Science Center, P.O. Box 26732, Tucson, AZ 85726 (United States)
  6. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)
Publication Date:
OSTI Identifier:
22270560
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 777; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; BLACK HOLES; GALAXIES; GALAXY NUCLEI; INFRARED SPECTRA; STAR CLUSTERS; VISIBLE SPECTRA; WAVELENGTHS; X-RAY SPECTRA