Faint Object Spectrograph Spectra of the Broad Fe II Absorption Lines in the Remnant of SN 1006

Abstract

Ultraviolet spectra of a hot subdwarf star located behind the remnant of SN 1006 have been obtained with the Faint Object Spectrograph on the Hubble Space Telescope. The FOS UV spectra show strong and extremely broad Fe II λ2343, λ2374, λ2382, λ2586, and λ2599 lines in absorption from the supernova remnant, confirming an earlier detection with the International Ultraviolet Explorer. The better resolution and signal-to-noise of the FOS spectra allow for the removal of narrow interstellar and stellar lines and the deblending of the broad Fe II lines, resulting in an intrinsic Fe II profile suitable for detailed comparison with model predictions.

The velocity profile of the ejecta is approximately symmetric around 0 km s^-1 and extends up to ±8300 km s^-1 at the continuum. The absorption-line width and angular size of the remnant yield a lower limit of 1.9 kpc to the distance of the remnant. The remnant contains approximately 0.014 M_sun of Fe⁺.