HIGH-RESOLUTION 6450-24500-A SPECTRA OF ETA-CARINAE

We discuss high-resolution (DELTAlambda/lambda almost-equal-to 3000-8600) spectra of the central knot or ''star'' in eta Car between approximately 6450 and approximately 24,500 angstrom, and of the Homunculus approximately 7'' southeast of the knot between approximately 6450 and approximately 9250 angstrom. A complete flux calibrated list of more than 170 emission lines is provided longward of approximately 8780 angstrom, with additional measurements of the strongest forbidden lines and Fe II features down to approximately 6700 angstrom. The generally strong N I and weak O I lines are consistent with an abundance mixture resulting from CNO burning in stellar envelopes, thus supporting the interpretation of eta Car as an evolved massive star. The continuum flux increased by a factor of approximately 1.6 to approximately 2.0 at 23,000 angstrom compared to recent measurements, but remained the same at approximately 11,000 angstrom. This brightening and reddening of the IR continuum was accompanied by stronger H I and He I lines, constant or slightly weaker Fe II and [Fe II] lines, and increased extinction to A(V) approximately 5m to 6m (from A(V) less than or similar to 3.2m previously). The complex line profiles fall into two categories: (1) broad emission and sometimes blueshifted absorptions that form in a high-velocity wind reaching at least 700 km s-1, and (2) narrow emission cores that may be associated with a low-velocity (equatorial?) wind with speeds less than or equal to 100 km s-1. The broad lines in the Homunculus have profiles and equivalent widths similar to the broad components in the knot, but they are redshifted by greater than or similar to 250 km s-1 due to rapid expansion of the reflecting dust. The reflected light spectrum of the Homunculus offers a better ''view'' of the high-velocity wind because it is free of the many strong narrow lines in the knot. For example, the Homunculus spectrum clearly shows lower velocity absorptions in O I lambda7773 compared to H I and He I, suggesting deceleration of the high-speed wind at large radii. The range of excitation in both the high- and low-velocity regions encompasses He I recombination and Fe II emission, but excludes the lower ionization required for Fe I, the CO band heads, and the infrared Ca II triplet, which are not detected. The narrow forbidden lines indicate densities in excess of the critical densities, ranging from approximately 10(4) to nearly 10(7) cm-1. The narrow permitted lines are slightly broader than the forbidden lines and probably form in a denser region nearer the central star. All of the strongest Fe II lines at wavelengths greater than or equal to 7000 angstrom, in both the broad and narrow-line regions, can be attributed to cascades from excited states that are ''pumped'' by resonant absorption of H I Lyalpha. This process requires partially ionized gas and densities greater than or equal to 10(5) cm-3.