GALEX Blasts Off Science Lecture Series

Isiah Reyes

An adventure in ultraviolet with the Galaxy Evolution Explorer was experienced by a full house on Sept. 22 featuring Caltech speaker Dr. James Don Neill in the ongoing Science Lecture series on campus.

The free lecture was held in the Santa Barbara building at noon and focused on the orbiting space telescope known as GALEX, which observes galaxies in ultraviolet light across 10 billion years of cosmic history.

Neill, a senior postdoctoral scholar at Caltech, discussed the GALEX mission, the expected and unexpected results of its findings and other details about the telescope, such as its cost, dimensions and abilities.

“If you want to learn a lot about galaxies that are distant, you are restricted to essentially detecting radiation from those galaxies,” Neill said.

The telescope specializes in detecting ultraviolet wavelengths.

Poghos Kazarian, professor of general physics on campus, said, “From time to time, you get very high energy objects being born and they give you a splash of ultraviolet.”
This helps scientists map together the universe’s past.

Astronomical discoveries require new and advanced technologies to help measure unexplained phenomena that occur throughout the galaxy. The telescope uses one of the most sensitive, wide-field ultraviolet detectors available. It can help give a better understanding of localized and universal star formation.

“The process you want to desire is to basically observe our universe with more precision, more accuracy and with more scope,” Neill said.

Neill explained how a typical galaxy, the basic structure of our universe, continues to evolve and change. He stated that young galaxies tend to be blue in color, whereas older galaxies (such as our own sun) tend to comprise of a red color. Transitional stars are green in color.

“[GALEX] gives more detailed information about how stars and galaxies evolve,” Kazarian said. “High intensity stars basically live fast and die young. The bigger your mass, the faster you burn.”
Led by the California Institute of Technology, GALEX is conducting several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey.

During its mission, the telescope will produce the first comprehensive map of a universe of galaxies under construction, bringing a better understanding of how galaxies like our own Milky Way were formed.
GALEX was successfully launched on April 28, 2003 at 8 a.m. from Cape Canaveral, Fla. It has a 384-mile orbit and orbits Earth every 98 minutes.

It consists of two detectors, one of which detects far ultraviolet wavelengths (150 nanometers) and the other which detects near ultraviolet wavelengths (250 nanometers).
All GALEX data is archived, hosted and made publicly available through the Multi-Mission archive at the Space Telescope Science Institute.

The telescope is also available for guest investigators to use for their own projects.
Partnering with the Jet Propulsion Laboratory on the mission are Caltech; Orbital Sciences Corporation, Germantown, Md.; UC Berkeley; Yonsei University, Seoul, Korea; Johns Hopkins University, Baltimore, Md.; Columbia University, N.Y. and Laboratoire d’Astrophysique de Marseille, France.

A power surge on May 29 shut the telescope down. The project reviewed data from the incident and confirmed it had the same characteristics as three previous incidents occurring in 2005, 2006 and 2007.

Presently, the GALEX project is performing a series of actions to remove debris believed to be causing the shorting condition from within the detector. The actions require multiple on-and-off cycling of the detector at various voltage levels, followed by an analysis of the results. The voltage and current settings are then adjusted, and the process is repeated.

To make up for its lost time and observations, the project plans to use its far-ultraviolet detector when it resumes operations.

The discoveries made by the telescope are important to scientists and non-scientists alike. The more breakthroughs that are being unearthed, the more it will help lead into a future where technological advancements can help improve our understanding of the universe.

The Science Lecture Series is coordinated by Dr. Sid Kolpas. The next science lecture is called “From the Beginning to the End… and Everything in Between (System Error: Please Reinstall the Universe and Reboot)” and will be held on Oct. 27 by Kazarian in SB 243. It is free and open to the public.

The GCC Cosmology and Astrophysics Club will also be presenting a lecture as part of the Humanities Lecture Series called “The Anthropology of Star Trek and Star Wars” on Oct. 8 in Kreider Hall at noon. It will be presented by Daryl Frazetti from Western Nevada College.