2001/02/09 by E. Oliva, A. Marconi, R. Maiolino +19 · 1 citation
Physics and Astronomy · #Active galactic nucleus #Astronomy and Astrophysical Research #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Infrared #Line (geometry) #Luminous infrared galaxy #Spectroscopy #Stellar, planetary, and galactic studies #Supernova #astro-ph
paper · pdf · doi:10.1051/0004-6361:20010214
4 pages, accepted for publication in A&A
arxiv created 2001/02/09 · openalex publication_date 2001/04/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report 0.9-1.4 μm spectroscopic observations of NGC 1068 collected during the commissioning phase of the near infrared camera spectrometer (NICS) of the Telescopio Nazionale Galileo (TNG). These yielded the first extragalactic measurement of [ PII] (1.188 μm) line emission. In the central the [ FeII] /[ PII] line-intensity ratio is close to unity, similar to that measured in the Orion bar and a factor of 20 smaller than in supernova remnants. This indicates that most of iron is locked into grains and, therefore, argues against shock excitation being the primary origin of [ FeII] line emission in the central regions of NGC 1068. We propose the [ FeII] /[ PII] ratio as a simple and effective tool to study and perhaps resolve the long debated questions related to the origin of [ FeII] line emission and, more generally, to constrain the role of shock excitation in active galaxies.