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High-resolution 6450-24500 A spectra of eta CarinaeWe discuss high-resolution (Delta lambda/lambda approximately equals 3000-8600) spectra of the central knot or 'star' in eta Car between approximately 6450 and approximately 24,500 A, and of the Homunculus approximately 7 sec southeast of the knot between approximately 6450 and approximately 9250 A. A complete flux calibrated list of more than 170 emission lines is provided longward of approximately 8780 A, with additional measurements of the strongest forbidden lines and Fe II features down to approximately 6700 A. The continuum flux increased by a factor of approximately 1.6 to approximately 2.0 at 23,000 A compared to recent measurements, by remained the same at approximately 11,000 A. 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(sub V) approximately 5 mag to 6 mag (from A(sub V) approximately less than 3.2 mag 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 and (2) narrow emission cores that may be associated with a low-velocity (equatorial?) wind with speeds approximately less than 100 km/s. The broad lines in the Homunculus have profiles and equivalent widths similar to the broad components in the know, but they are redshifted by approximately greater than 250 km/s 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. 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(exp 4) to nearly 10(exp 7)/cu cm. 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 approximately greater than 7000 A, 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 Lyman alpha.
Document ID
19950036099
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Hamann, Fred
(Ohio State Univ. Columbus, OH, United States)
Depoy, D. L.
(Ohio State Univ. Columbus, OH, United States)
Johansson, Sveneric
(Univ. of Lund Lund, Sweden)
Elias, Jay
(Cerro Tololo Inter-American Observatory La Serena, Chile)
Date Acquired
August 16, 2013
Publication Date
February 20, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 422
Issue: 2
ISSN: 0004-637X
Subject Category
Astronomy
Accession Number
95A67698
Funding Number(s)
CONTRACT_GRANT: NAG5-1645
Distribution Limits
Public
Copyright
Other

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