Unlike some integral field units (IFUs) in front of conventional slit spectrographs, PMAS is a dedicated fiber-optical integral field spectrograph, featuring two different types of IFUs to address both high spatial resolution and wide field-of-view (FoV) in a single instrument. The instrument was designed, built, and tested completely in-house at the Astrophysical Institute Potsdam from 1996 to 2000. It was commissioned at the Calar Alto 3.5m Telescope in May 2001. PMAS employs an all-refractive fiber spectrograph, built with CaF₂ optics, to provide good transmission and high image quality over the entire nominal wavelength range. A set of user-selectable reflective gratings provides low to medium spectral resolution in first order of approx. 1.5, 3.2, and 7 Å, depending on the groove density (1200, 600, 300 gr/mm). The standard IFU uses a 16×16 element lens array, which provides seeing-limited sampling in a relatively small field-of-view (FOV) in one of three magnifications (8×8, 12×12, or 16×16 arcsec², respectively). The additional fiber bundle IFU (PPak) expands the FOV to a hexagonal area with a footprint of 65×74 arcsec².

Date Published: 27 June 2006
PDF: 10 pages
Proc. SPIE 6269, Ground-based and Airborne Instrumentation for Astronomy, 62690H (27 June 2006); doi: 10.1117/12.672091

Published in SPIE Proceedings Vol. 6269:
Ground-based and Airborne Instrumentation for Astronomy
Ian S. McLean; Masanori Iye, Editor(s)