With human life seldom lasting longer than a century, it is hard to imagine the life cycle of galaxies that have been growing, moving and existing for billions of years. St. Michael’s physics professor Dr. John O’Meara is working on a team dedicated to understanding younger galaxies, in the hopes of better understanding the entire galaxy life cycle.
Applying for telescope time
O’Meara is serving as the principal investigator on a team of researchers from eight universities including the University of California – Santa Cruz, the University of Chicago and the University of Notre Dame.
Through a rigorous application process, the group managed to be granted use of the Hubble space telescope, and with it, two grants totaling over $300,000 from the Space Telescope Institute of NASA.
“Most telescopes, you apply for time and then you apply to a second agency for money,” O’Meara says. “In the case of the Hubble, you get money to do the observations and that comes directly from NASA, so they operate the telescope and they also give you the money to do data analysis.”
"He has some great ideas and knows how to work with those ideas," says Jason Prochaska, another member of the research team.
(Photo by Cailey McDermott)
The window to submit proposals is around 18 months, and a detailed idea must be presented on the proposed studies.
“It’s what you want to use the telescope for and why you should be given this time. That’s where most of the competition is,” O’Meara says.
One reason there is so much competition in the scientific community is because there are limited resources available for visual space research.
“There are many, many more proposals than there is time on the telescope, partly because there aren’t many telescopes in space,” O’Meara says.
“Getting telescope time is very competitive and about only one in 10 proposals are awarded for both the observatory and the Hubble. I’m proud to be pursuing science at both of those locations,” says Jason Prochaska, a member of the team from UC - Santa Cruz.
Around five months after the team submitted the proposal - it was approved. That meant the team had to work to articulate financing, as well as the finer details of the research for a second-phase proposal, O'Meara says.
A large amount of the grant will go to funding graduate students and post-doctoral researchers, but other costs include computers, hard drives and travel to the Keck Observatory in Hawaii for a follow-up observation, he says.
Surveying the stars
Much of the work will be dedicated to imaging and analyzing galaxies that are faint, or not visible without the Hubble’s high-resolution lenses. The team will also be taking spectrums of quasars, very large, bright objects in space, in the hopes of finding the young galaxies, O’Meara says.
“Quasars are used as a background light source, and if a galaxy gets in the way, it will absorb some light,” he says. “Looking at that absorption, you can tell how much carbon, how much hydrogen, and whatever is in that galaxy.”
The team will rely on two kinds of images during their research. The first are images of objects in space taken from observatories on Earth and through the Hubble. In order to more precisely identify the make-up of these objects, researchers will also require a second type of image, the spectrum.
O'Meara and the other researchers worked together on the proposals online before meeting to decide the finer points of research.
(Photo by Cailey McDermott)
“A spectrum is when you take light and pass it through a prism and it spreads the light out as a function of wavelength,” O’Meara says. “That’s important because depending on what atoms are in the thing, you’ll see little absorption or emission featured on the top of the spectrum.”
The observation of damped Lyman alpha systems (DLAs), gives researchers a snapshot to what the universe was producing billions of years ago.
“They were around when the universe was 15 percent of its age now,” O’Meara says. “The universe was much younger when these galaxies were being formed.”
The Milky Way was formed further in the universal timeline, and most of the neighboring galaxies fall between 10 and 12 billion years old.
“We do large telescope surveys to try and sample galaxies at their different stages of evolution because things in astronomy change on very, very long-time scales,” O’Meara says. “Our galaxy looks the same as it did five billion years ago.”
In order to absorb the multi-billion year process a galaxy undergoes, researchers try to find a wide range of galaxies at different points of the life cycle, in a manner similar to researchers conducting a survey like the census.
“The same way of doing the census you sample a couple hundred million people, and you’re guaranteed to get a couple babies and a couple of hundred-year-olds,” O’Meara says.
Clouds over Keck
O’Meara and the team of researchers depend heavily on several factors to ensure productive use of allocated time at the Keck observatory.
The Keck Observatory in Hawaii serves a central role in the team's research.
(Photo courtesy of John O'Meara)
“Unfortunately you can’t just take data and get a pretty picture and then stick it in a paper and say this is a picture of a galaxy,” O’Meara says. “A color picture in astronomy is actually one picture taken in red, one picture taken in green, and one picture taken in blue, and then you Photoshop them together to get your color image.”
The Hubble telescope is also a source of concern, given impending repairs to older technology on the spacecraft, and the limited time it is available for use during a typical research cycle.
“Part of the time it cannot look at science objects because it’s sunny,” O’Meara says. “But all of this, all this money and time is contingent on them fixing the telescope, and fixing things in space is hard.”
The telescope’s constant rotation around the Earth also means that researchers must wait until the Hubble is in low orbit in order to use it, but it is nonetheless able to avoid weather that could jeopardize the team’s observations.
“It’s hard to deal with… weather is weather,” Prochaska says. “That’s beyond our control, though.”
There are but the typical concerns of research, that O'Meara knows well.
"If you get your one night a semester and you get clouded out, they don't say, 'oh I'm sorry, that's bad, we'll give you another night,' no, that's not how it works," he says. "If you're clouded out, you're clouded out, tough, sorry, we'll see you next year, maybe."