Wisconsin H-Alpha Mapper
The Wisconsin H-Alpha Mapper is a custom-built telescope operated by the University of Wisconsin–Madison, used to study the Hydrogen-alpha ions of the warm ionized medium. It is a tenant telescope at the Cerro Tololo Inter-American Observatory, in the Coquimbo Region of northern Chile.History
First interest in the ionised hydrogen of the interstellar medium came when Ron Reynolds pointed a spectrometer through a makeshift observing portal in an office of the University of Wisconsin-Madison's Physical Sciences Laboratory during the late 1970s. Reynolds and colleagues, including Matt Haffner, a senior scientist in UW-M's astronomy department, later developed WHAM.
WHAM formally began life at Kitt Peak National Observatory in November 1996, using the flat mirrors of a two axis, all-sky siderostat passing light horizontally through a 0.6 m diameter, 8.6 m focal length objective lens into a 2.5 m x 2.5 m x 6 m trailer that contained the spectrometer, that used a low noise, high efficiency CCD camera as a multichannel detector behind a pair of diameter Fabry-Perot etalons/spectrometers. The system was automated, so that the entire WHAM facility, including opening and closing at the beginning and end of the observing night, was operated from a campus office at the University of Wisconsin in Madison. It operated there from 1996 to 2008.
In 2009, WHAM was moved from KPNO to CTIO.
WHAM's field of view allows a whole sky survey in about 2 years. WHAM mapped the details of the Reynolds Layer.
