η Carinae: linelist for the emission spectrum of the Weigelt blobs in the 1700 to 10 400 Å wavelength region^⋆

¹ Atomic Astrophysics, Lund Observatory, Lund University, Box 43, 22100 Lund, Sweden
e-mail: Henrik.Hartman@astro.lu.se
² Astrophysics Science Division, Code 667, Goddard Space Flight Center, Greenbelt, MD 20771, USA
e-mail: Theodore.R.Gull@nasa.gov

Received: 11 February 2011
Accepted: 27 January 2012

Abstract

Aims. We present line identifications in the 1700 to 10 400 Å region for the Weigelt blobs B and D, located 0″.1 to 0″.3 NNW of Eta Carinae. The aim of this work is to characterize the behavior of these luminous, dense gas blobs in response to the broad high-state and the short low-state of η Carinae during its 5.54-year spectroscopic period.

Methods. The spectra were recorded in a low state (March 1998) and an early high state (February 1999) with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) from 1640 to 10 400 Å using the 52″ × 0″.1 aperture centered on Eta Carinae at position angle, PA  =  332 degrees. Extractions of the reduced spectrum including both Weigelt B and D, 0″.28 in length along the slit, were used to identify the narrow, nebular emission lines, measure their wavelengths and estimate their fluxes.

Results. A linelist of 2500 lines is presented for the high and low states of the combined Weigelt blobs B and D. The spectra are dominated by emission lines from the iron-group elements, but include lines from lighter elements including parity-permitted and forbidden lines. A number of lines are fluorescent lines pumped by H Lyα. Other lines show anomalous excitation.