Topic: Gravitational Lensing
Greenbelt, MD – NASA reports that Astronomers have discovered that there may be a missing ingredient in our cosmic recipe of how dark matter behaves.
They have uncovered a discrepancy between the theoretical models of how dark matter should be distributed in galaxy clusters, and observations of dark matter’s grip on clusters.
Dark matter does not emit, absorb, or reflect light. Its presence is only known through its gravitational pull on visible matter in space. Therefore, dark matter remains as elusive as Alice in Wonderland’s Cheshire Cat – where you only see its grin (in the form of gravity) but not the animal itself.
Greenbelt, MD – New results from the NASA/ESA Hubble Space Telescope suggest the formation of the first stars and galaxies in the early universe took place sooner than previously thought. A European team of astronomers have found no evidence of the first generation of stars, known as Population III stars, as far back as when the universe was just 500 million years old.
The exploration of the very first galaxies remains a significant challenge in modern astronomy. We do not know when or how the first stars and galaxies in the universe formed.
Washington, D.C. – The universe is a big place. NASA’s Hubble Space Telescope’s views burrow deep into space and time, but cover an area a fraction the angular size of the full Moon. The challenge is that these “core samples” of the sky may not fully represent the universe at large.
This dilemma for cosmologists is called cosmic variance. By expanding the survey area, such uncertainties in the structure of the universe can be reduced.
Space Telescope Science Institute
Baltimore, MD – More than halfway across the universe, an enormous blue star nicknamed Icarus is the farthest individual star ever seen. Normally, it would be much too faint to view, even with the world’s largest telescopes.
But through a quirk of nature that tremendously amplifies the star’s feeble glow, astronomers using NASA’s Hubble Space Telescope were able to pinpoint this faraway star and set a new distance record. They also used Icarus to test one theory of dark matter, and to probe the make-up of a foreground galaxy cluster.
NASA’s Hubble and Spitzer Space Telescopes discover farthest Galaxy seen to date using Gravitational Lensing
Written by Laurie Cantillo / Dwayne Brown
Washington, D.C. – An intensive survey deep into the universe by NASA’s Hubble and Spitzer space telescopes has yielded the proverbial needle-in-a-haystack: the farthest galaxy yet seen in an image that has been stretched and amplified by a phenomenon called gravitational lensing.
The embryonic galaxy named SPT0615-JD existed when the universe was just 500 million years old. Though a few other primitive galaxies have been seen at this early epoch, they have essentially all looked like red dots, given their small size and tremendous distances. However, in this case, the gravitational field of a massive foreground galaxy cluster not only amplified the light from the background galaxy but also smeared the image of it into an arc (about 2 arcseconds long).
Written by Elizabeth Landau
Pasadena, CA – What is our universe made of, and has its composition changed over time? Scientists have new insights about these fundamental questions, thanks to an international collaboration of more than 400 scientists called the Dark Energy Survey (DES).
Three scientists from NASA’s Jet Propulsion Laboratory in Pasadena, California, are part of this group that is helping to further our understanding of the structure of the universe.
The advances in astrophysics from DES are crucial to preparations for two upcoming space missions that will probe similar questions about the nature of the universe: ESA’s Euclid mission (which has significant NASA participation) and NASA’s Wide-Field Infrared Survey Telescope mission, both expected to launch in the 2020s.
NASA Goddard Space Flight Center
Greenbelt, MD – When it comes to the distant universe, even the keen vision of NASA’s Hubble Space Telescope can only go so far. Teasing out finer details requires clever thinking and a little help from a cosmic alignment with a gravitational lens.
By applying a new computational analysis to a galaxy magnified by a gravitational lens, astronomers have obtained images 10 times sharper than what Hubble could achieve on its own. The results show an edge-on disk galaxy studded with brilliant patches of newly formed stars.
Written by Arielle Samuelson
Washington, D.C. – In the “Star Wars” universe, ice, ocean and desert planets burst from the darkness as your ship drops out of light speed. But these worlds might be more than just science fiction.
Some of the planets discovered around stars in our own galaxy could be very similar to arid Tatooine, watery Scarif and even frozen Hoth, according to NASA scientists.
Written by Elizabeth Landau
Pasadena, CA – In the ongoing hunt for the universe’s earliest galaxies, NASA’s Spitzer Space Telescope has wrapped up its observations for the Frontier Fields project. This ambitious project has combined the power of all three of NASA’s Great Observatories — Spitzer, the Hubble Space Telescope and the Chandra X-ray Observatory — to delve as far back in time and space as current technology can allow.
Even with today’s best telescopes, it is difficult to gather enough light from the very first galaxies, located more than 13 billion light years away, to learn much about them beyond their approximate distance.
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