STRONG [FE-II] EMISSION FROM NGC-1275

Infrared spectroscopy of the central region of NGC 1275 has revealed a n unusually strong [Fe II] lamdba12567 feature. Although the redshift of this line matches those of the lines of the active nucleus, its muc h narrower profile signifies its origin in a different volume of gas. The strength of the [Fe II] feature compared to the other emission lin es from the central region indicates that iron remains relatively unde pleted from the interstellar medium of NGC 1275. While other agents ma y contribute to the [Fe II] emission, we propose that the bulk of the emission is excited by wide-spread shocks. These shocks enrich the iro n content of the interstellar medium, excite the extensive low-ionizat ion regions which produce the [Fe II] flux, and contribute to the othe r low-excitation features which are so distinctive in the spectrum of NGC 1275. These shocks could result from supernova explosions, the acc retion on intracluster material, galaxy-galaxy interactions, or some p rocess associated with the active nucleus, but our observations do not distinguish among these phenomena. However, if supernovae generate th e shocks, then a very high, and observable, supernovae rate of approxi mately 3 yr-1 is implied by the [Fe II] luminosity. The presence of an [Fe II] feature comparable in brightness to the nuclear Pabeta emissi on, but exhibiting a very different profile, makes NGC 1275 an unambig uous example of a luminous active galaxy where the [Fe II] emission do es not originate in the active nucleus, and probably is not powered by the nuclear continuum source. While this observation of NGC 1275 does not exclude the active nucleus as the principal source of the strong [Fe II] emission detected in other active galaxies, it does indicate t hat other agents (e.g., shocks) can compete favorably in the productio n of the [Fe II] lines.