Spitzer Telescope
How NASA’s Spitzer Has Stayed Alive for So Long
Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
calla.e.cofield@jpl.nasa.gov
After nearly 16 years of exploring the cosmos in infrared light, NASA’s Spitzer Space Telescope will be switched off permanently on Jan. 30, 2020. By then, the spacecraft will have operated for more than 11 years beyond its prime mission, thanks to the Spitzer engineering team’s ability to address unique challenges as the telescope slips farther and farther from Earth.
Managed and operated by NASA’s Jet Propulsion Laboratory in Pasadena, California, Spitzer is a small but transformational observatory. It captures infrared light, which is often emitted by “warm” objects that aren’t quite hot enough to radiate visible light. Spitzer has lifted the veil on hidden objects in nearly every corner of the universe, from a new ring around Saturn to observations of some of the most distant galaxies known. It has spied stars in every stage of life, mapped our home galaxy, captured gorgeous images of nebulas and probed newly discovered planets orbiting distant stars.
NASA Space Telescopes See Magnified Image of Faintest Galaxy from Early Universe
Astronomers harnessing the combined power of NASA’s Hubble and Spitzer space telescopes have found the faintest object ever seen in the early universe. It existed about 400 million years after the big bang, 13.8 billion years ago.
The team has nicknamed the object Tayna, which means “first-born” in Aymara, a language spoken in the Andes and Altiplano regions of South America.
Though Hubble and Spitzer have detected other galaxies that are record-breakers for distance, this object represents a smaller, fainter class of newly forming galaxies that until now had largely evaded detection. These very dim objects may be more representative of the early universe, and offer new insight on the formation and evolution of the first galaxies.
“Thanks to this detection, the team has been able to study for the first time the properties of extremely faint objects formed not long after the big bang,” said lead author Leopoldo Infante, an astronomer at the Pontifical Catholic University of Chile. The remote object is part of a discovery of 22 young galaxies at ancient times located nearly at the observable horizon of the universe. This research means there is a substantial increase in the number of known very distant galaxies.
The results are published in the December 3 issue of The Astrophysical Journal.
The new object is comparable in size to the Large Magellanic Cloud, a diminutive satellite galaxy of our Milky Way. It is rapidly making stars at a rate 10 times faster than the Large Magellanic Cloud. The object might be the growing core of what will likely evolve into a full-sized galaxy.
The small and faint galaxy was only seen thanks to a natural “magnifying glass” in space. As part of its Frontier Fields program, Hubble observed a massive cluster of galaxies, MACS0416.1-2403, located roughly 4 billion light-years away and weighing as much as a million billion suns. This giant cluster acts as a powerful natural lens by bending and magnifying the light of far more distant objects behind it. Like a zoom lens on a camera, the cluster¹s gravity boosts the light of the distant proto-galaxy to make it look 20 times brighter than normal. The phenomenon is called gravitational lensing and was proposed by Albert Einstein as part of his General Theory of Relativity.
The galaxy’s distance was estimated by building a color profile from combined Hubble and Spitzer observations. The expansion of the universe causes the light from distant galaxies to be stretched or reddened with increasing distance. Though many of the galaxy’s new stars are intrinsically blue-white, their light has been shifted into infrared wavelengths that are measurable by Hubble and Spitzer. Absorption by intervening cool intergalactic hydrogen also makes the galaxies look redder.
This finding suggests that the very early universe will be rich in galaxy targets for the upcoming James Webb Space Telescope to uncover. Astronomers expect that Webb will allow us to see the embryonic stages of galaxy birth shortly after the big bang.
For more information, visit http://www.nasa.gov/hubble or http://www.nasa.gov/spitzer.
Whopping Galaxy Cluster Spotted with Help of NASA Telescopes
Astronomers have discovered a giant gathering of galaxies in a very remote part of the universe, thanks to NASA’s Spitzer Space Telescope and Wide-field Infrared Survey Explorer (WISE). The galaxy cluster, located 8.5 billion light-years away, is the most massive structure yet found at such great distances.
Galaxy clusters are gravitationally bound groups of thousands of galaxies, which themselves each contain hundreds of billions of stars. The clusters grow bigger and bigger over time as they acquire new members.
How did these clusters evolve over time? What did they look like billions of years ago? To answer these questions, astronomers look back in time to our youthful universe. Because light takes time to reach us, we can see very distant objects as they were in the past. For example, we are seeing the newfound galaxy cluster — called Massive Overdense Object (MOO) J1142+1527 — as it existed 8.5 billion years ago, long before Earth formed.
As light from remote galaxies makes its way to us, it becomes stretched to longer, infrared wavelengths by the expansion of space. That’s where WISE andSpitzer help out.
For infrared space telescopes, picking out distant galaxies is like plucking ripe cherries from a cherry tree. In the infrared images produced by Spitzer, these distant galaxies stand out as red dots, while closer galaxies look white. Astronomers first combed through the WISE catalog to find candidates for clusters of distant galaxies. WISE catalogued hundreds of millions of objects in images taken over the entire sky from 2010 to 2011.
They then used Spitzer to narrow in on 200 of the most interesting objects, in a project named the “Massive and Distant Clusters of WISE Survey,” or MaDCoWS. Spitzer doesn’t observe the whole sky like WISE, but can see more detail.
“It’s the combination of Spitzer and WISE that lets us go from a quarter billion objects down to the most massive galaxy clusters in the sky,” said Anthony Gonzalez of the University of Florida in Gainesville, lead author of a new study published in the Oct. 20 issue of the Astrophysical Journal Letters.
From these observations, MOO J1142+1527 jumped out as one of the most extreme.
The W.M. Keck Observatories and Gemini Observatory on Mauna Kea in Hawaii were used to measure the distance to the cluster at 8.5 billion light-years. Using data from the Combined Array for Research in Millimeter-wave Astronomy (CARMA) telescopes near Owens Valley in California, the scientists were then able to determine that the cluster’s mass is a quadrillion times that of our sun — making it the most massive known cluster that far back in space and time.
MOO J1142+1527 may be one of only a handful of clusters of this heft in the early universe, according to the scientists’ estimates.
“Based on our understanding of how galaxy clusters grow from the very beginning of our universe, this cluster should be one of the five most massive in existence at that time,” said co-author Peter Eisenhardt, the project scientist for WISE at NASA’s Jet Propulsion Laboratory in Pasadena, California.
In the coming year, the team plans to sift through more than 1,700 additional galaxy cluster candidates with Spitzer, looking for biggest of the bunch.
“Once we find the most massive clusters, we can start to investigate how galaxies evolved in these extreme environments,” said Gonzalez.
JPL managed and operated WISE for NASA’s Science Mission Directorate in Washington. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA’s efforts to identify potentially hazardous near-Earth objects. JPL manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations and data processing for Spitzer and NEOWISE take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
More information about WISE is online at: http://www.nasa.gov/wise
More information about Spitzer is online at: http://www.nasa.gov/spitzer and http://spitzer.caltech.edu
Cosmology & Space Research Institute 