Infrared wavelengths are providing images of galaxies long dead. The Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) is allowing scientists to study galaxies far, far away. It was developed for the Cassegrain focus of the 10 m Keck 1 telescope and. has been installed at the observatory atop Mauna Kea which stands 13,796 feet above sea level on Big Island Hawaii.
Light that has been "redshifted" or stretched to the infrared spectrum by the expansion of the universe is providing information to scientists. Ian S. McLean, director of UCLA?s Infrared Laboratory for Astrophysics, and co project leader with Caltech?s Charles Steidel, said: "We are looking back in time to the era of the formation of some of the very first galaxies, which are small and very faint. That is an era that we need to study if we are going to understand the large-scale structure of the universe." MOSFIRE will undergo testing and evaluation in the coming months. Seen here is one of its first images taken under cloudy conditions with only a 60 second exposure.
MOSFIRE image of two colliding galaxies, the Antennae in the constellation of Corvus, about 45 million light years from Earth. Credit: Ian S. McLean/W.M. Keck Observatory
Sitting atop Mauna Kea, a Hawaiian volcano, MOSFIRE is aptly named. Pele, goddess of volcanoes and fire, is said to dwell in the craters of another of Big Island’s volcanoes, Kilauea. They say her face appears mysteriously in their fiery eruptions. The ancient goddess is revered by Christian, Buddhist, and Shinto inhabitants of the Hawaiian Islands. Like the Hindu Shiva, Pele destroys, yet she also builds. Her caustic fire flows over structures and earth, cooling to a lifeless, dark river of lava. The same lava flows seaward and in the last 30 years has added more than 70 acres of new land along the coastline on the island?s southeastern border.
While the fiery volcanic eruptions are stunningly visible, the infrared being picked up by the new five ton instrument cannot be seen by the human eye. McLean has been involved in building sophisticated infrared cameras and spectrometers which split light into its component colors since the 1980?s. The $14 million tab for his latest project was funded by the National Science Foundation through the Telescope System Instrumentation program and Gordon Moore co-founder of Intel. "We had an outstanding team," according to McLean, "with four institutions involved and many industrial partners. It was a fantastic team effort."
MOSFIRE optical train folded in three dimensions
MOSFIRE’s camera has four megapixels, whereas an earlier infrared spectrometer called NIRSPEC, also at the Keck Observatory, had only one. Modern digital imaging makes it extremely sensitive to faint objects. Another camera that McLean and his colleagues built, FLITECAM, can be converted to a spectrometer electronically, using a computer. It will go into operation on NASA’s SOFIA (Stratospheric Observatory for Infrared Astronomy). The world?s largest airborne observatory, the modified Boeing 747 SP jetliner will study planets orbiting other stars and stars eclipsed when an asteroid or comet in the outer part of the solar system passes in front of them.
To better understand how it is possible to take digital pictures across the electromagnetic spectrum at any wavelength, from gamma rays to radio waves, pick up a copy of McLean?s "Electronic Imaging in Astronomy: Detectors and Instrumentation." To learn more about the design and development of MOSFIRE, click here.