Resonance-Enhanced Two-Photon Ionization (RETPI) of SiII and an Anomalous, Variable Intensity of the 1892A SiIII] Line in the Weigelt Blobs of Eta Carinae

Abstract

The Si III] 1892A intercombination line shows an anomalously high intensity in spectra of the radiation-rich Weigelt blobs in the vicinity of Eta Carinae. The line disappears during the 100 days long spectral events occurring every 5.5 years. The aim is to investigate whether resonance-enhanced two-photon ionization (RETPI) is a plausible excitation mechanism for the Si III] 1892A line. The possible intensity enhancement of the 1892A line is investigated as regards quasi-resonant intermediate energy levels of Si II. The RETPI mechanism is effective on SiII in the radiation-rich Weigelt blobs where the two excitation steps are provided by the two intense hydrogen lines Ly alpha and Ly gamma

arXiv comment4 pages, Accepted for publication in A&A

References in corpus (3)

• Latitude-dependent effects in the stellar wind of Eta Carinae
• Direct measurement of the size and shape of the present-day stellar wind of Eta Carinae
• Time variations of the narrow FeII and HI spectral emission lines from the close vicinity of Eta Carinae during the spectral event of 2003

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• Accretion onto the Companion of Eta Carinae During the Spectroscopic Event. IV. the Disappearance of Highly Ionized Lines
• Eta Carinae's Declining Outflow Seen in the UV, 2002-2015
• The peculiar chemistry of the inner ejecta of Eta Carina