Abstract
High-resolution spectra of molecular hydrogen in the Homunculus nebula allow for the first direct measurement of the systemic velocity of η Carinae. Near-infrared long-slit data for H2 1-0 S(1) λ21218 obtained with the Phoenix spectrometer on the Gemini South telescope give V sys = -8.1 ± 1 km s-1 (heliocentric), or V LSR = -19.7 ± 1 km s-1, from the average of the near and far sides of the Homunculus. This measurement considerably improves the precision for the value of -7 ± 10 km s-1 inferred from neighbouring O-type stars in the Carina nebula. New near-infrared spectra also provide a high-resolution line profile of [Fe II] λ16435 emission from gas condensations known as the Weigelt objects without contamination from the central star, revealing a line shape with complex kinematic structure. Previously, uncertainty in the kinematics of the Weigelt knots was dominated by the adopted systemic velocity of η Car.
| Original language | English (US) |
|---|---|
| Pages (from-to) | L15-L18 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 351 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jun 11 2004 |
| Externally published | Yes |
Keywords
- Circumstellar matter
- Stars: individual: η Car
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science