Nod Shuffle 3D Spectroscopy

摘要

We present first results from nod & shuffle 3D spectroscopy, obtained with the PMAS instrument at the Calar Alto 3. 5 m telescope in southern Spain. The nod & shuffle technique for accurate sky background subtraction has proven essential for the spectroscopy of faint surface brightness objects, which would otherwise be unobservable with conventional techniques. We present results from two applications: (1) measuring the line strengths of the calcium triplet lines in the optical near infrared for stellar population studies in elliptical galaxies, and (2) measuring faint diagnostic lines in the haloes of planetary nebulae to study the mass loss history of stars at the AGB. We present work in progress for these projects, which have yielded reliable Ca triplet gradient in an elliptical galaxy (NGC221) out to one effective radius for the first time, and unprecedented sensitivity in the case of haloes of planetary nebulae.