The nature of dark energy

First Use of Cosmic Lens to Probe Dark Energy

Astronomers have devised a new method for measuring perhaps the greatest puzzle of our universe — dark energy. This mysterious force, discovered in 1998, is pushing our universe apart at ever-increasing speeds.
This is the Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away. Dark matter in the cluster is mapped by plotting the plethora of arcs produced by the light from background galaxies that is warped by the foreground cluster's gravitational field. Dark matter cannot be photographed, but its distribution is shown in the blue overlay. The dark matter concentration and distribution is then used to better understand the nature of dark energy, a pressure that is accelerating the expansion of the universe. The imaging data used in the natural-color photo was taken in 2002 with Hubble's Advanced Camera for Surveys.

This is the Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away. Dark matter in the cluster is mapped by plotting the plethora of arcs produced by the light from background galaxies that is warped by the foreground cluster's gravitational field. Dark matter cannot be photographed, but its distribution is shown in the blue overlay. The dark matter concentration and distribution is then used to better understand the nature of dark energy, a pressure that is accelerating the expansion of the universe. The imaging data used in the natural-color photo was taken in 2002 with Hubble's Advanced Camera for Surveys.

For the first time, astronomers using NASA's Hubble Space Telescope were able to take advantage of a giant magnifying lens in space — a massive cluster of galaxies — to narrow in on the nature of dark energy. Their calculations, when combined with data from other methods, significantly increase the accuracy of dark energy measurements. This may eventually lead to an explanation of what the elusive phenomenon really is.

"We have to tackle the dark energy problem from all sides," said Eric Jullo, an astronomer at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It's important to have several methods, and now we've got a new, very powerful one." Jullo is lead author of a paper on the findings appearing in the Aug. 20 issue of the journal Science.

Scientists aren't clear about what dark energy is, but they do know that it makes up a large chunk of our universe, about 72 percent. Another chunk, about 24 percent, is thought to be dark matter, also mysterious in nature but easier to study than dark energy because of its gravitational influence on matter that we can see. The rest of the universe, a mere 4 percent, is the stuff that makes up people, planets, stars, and everything made up of atoms.

In their new study, the science team used images from Hubble to examine a massive cluster of galaxies, named Abell 1689, which acts as a magnifying, or gravitational, lens. The gravity of the cluster causes galaxies behind it to be imaged multiple times into distorted shapes, sort of like a fun-house mirror reflection that warps your face.

Using these distorted images, the scientists were able to figure out how light from the more distant, background galaxies had been bent by the cluster — a characteristic that depends on the nature of dark energy. Their method also depends on precise ground-based measurements of the distance and speed at which the background galaxies are traveling away from us. The team used these data to quantify the strength of the dark energy that is causing our universe to accelerate.

"What I like about our new method is that it's very visual," said Jullo, "You can literally see gravitation and dark energy bend the images of the background galaxies into arcs."

According to the scientists, their method required multiple, meticulous steps. They spent the last several years developing specialized mathematical models and precise maps of the matter — both dark and "normal" — constituting the Abell 1689 cluster.

"We can now apply our technique to other gravitational lenses," said co-author Priya Natarajan, a cosmologist at Yale University, New Haven, Conn. "We're exploiting a beautiful phenomenon in nature to learn more about the role that dark energy plays in our universe."

Source: Hubblesite
The nature of dark energy - First Use of Cosmic Lens to Probe Dark Energy | Redshift live

The nature of dark energy

First Use of Cosmic Lens to Probe Dark Energy

Astronomers have devised a new method for measuring perhaps the greatest puzzle of our universe — dark energy. This mysterious force, discovered in 1998, is pushing our universe apart at ever-increasing speeds.
This is the Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away. Dark matter in the cluster is mapped by plotting the plethora of arcs produced by the light from background galaxies that is warped by the foreground cluster's gravitational field. Dark matter cannot be photographed, but its distribution is shown in the blue overlay. The dark matter concentration and distribution is then used to better understand the nature of dark energy, a pressure that is accelerating the expansion of the universe. The imaging data used in the natural-color photo was taken in 2002 with Hubble's Advanced Camera for Surveys.

This is the Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away. Dark matter in the cluster is mapped by plotting the plethora of arcs produced by the light from background galaxies that is warped by the foreground cluster's gravitational field. Dark matter cannot be photographed, but its distribution is shown in the blue overlay. The dark matter concentration and distribution is then used to better understand the nature of dark energy, a pressure that is accelerating the expansion of the universe. The imaging data used in the natural-color photo was taken in 2002 with Hubble's Advanced Camera for Surveys.

For the first time, astronomers using NASA's Hubble Space Telescope were able to take advantage of a giant magnifying lens in space — a massive cluster of galaxies — to narrow in on the nature of dark energy. Their calculations, when combined with data from other methods, significantly increase the accuracy of dark energy measurements. This may eventually lead to an explanation of what the elusive phenomenon really is.

"We have to tackle the dark energy problem from all sides," said Eric Jullo, an astronomer at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It's important to have several methods, and now we've got a new, very powerful one." Jullo is lead author of a paper on the findings appearing in the Aug. 20 issue of the journal Science.

Scientists aren't clear about what dark energy is, but they do know that it makes up a large chunk of our universe, about 72 percent. Another chunk, about 24 percent, is thought to be dark matter, also mysterious in nature but easier to study than dark energy because of its gravitational influence on matter that we can see. The rest of the universe, a mere 4 percent, is the stuff that makes up people, planets, stars, and everything made up of atoms.

In their new study, the science team used images from Hubble to examine a massive cluster of galaxies, named Abell 1689, which acts as a magnifying, or gravitational, lens. The gravity of the cluster causes galaxies behind it to be imaged multiple times into distorted shapes, sort of like a fun-house mirror reflection that warps your face.

Using these distorted images, the scientists were able to figure out how light from the more distant, background galaxies had been bent by the cluster — a characteristic that depends on the nature of dark energy. Their method also depends on precise ground-based measurements of the distance and speed at which the background galaxies are traveling away from us. The team used these data to quantify the strength of the dark energy that is causing our universe to accelerate.

"What I like about our new method is that it's very visual," said Jullo, "You can literally see gravitation and dark energy bend the images of the background galaxies into arcs."

According to the scientists, their method required multiple, meticulous steps. They spent the last several years developing specialized mathematical models and precise maps of the matter — both dark and "normal" — constituting the Abell 1689 cluster.

"We can now apply our technique to other gravitational lenses," said co-author Priya Natarajan, a cosmologist at Yale University, New Haven, Conn. "We're exploiting a beautiful phenomenon in nature to learn more about the role that dark energy plays in our universe."

Source: Hubblesite
» print article
Related articles:
The Planck spacecraft, which was launched on 14 May 2009, scans the entire sky in the microwave range. Characteristics of dark energy will be derived from its observations.
Astronomy's Dark Side

What is dark energy?

» go to article
A cosmic concoction in NGC 2467
Hubble Space Telescope image of NGC 2467

Hubble snaps sharp image of cosmic concoction

» go to article
This broad vista of young stars and gas clouds in our neighbouring galaxy, the Large Magellanic Cloud, was captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS). This region is named LHA 120-N 11, informally known as N11, and is one of the most active star-forming regions in the nearby Universe. This picture is a mosaic of ACS data from five different positions and covers a region of about 6 arcmin across.
The Large Magellanic Cloud

Hubble captures bubbles and baby stars

» go to article
The core of the star cluster in NGC 3603 is shown in great detail in an image from the Wide Field Planetary Camera 2 (WFPC2) camera on the NASA/ESA Hubble Space Telescope. The image is a colour composite of observations in the WFPC2 filters F555W (blue), F675W (green) and F814W (red). This view shows the second of two images taken ten years apart that were used to detect the motions of individual stars within the cluster for the first time. The field of view is about 20 arcseconds across.
Surprising signs of unrest in massive star cluster

Hubble catches stars on the move

» go to article
This craggy fantasy mountaintop shrouded by wispy clouds looks like a bizarre landscape from Tolkien’s The Lord of the Rings. The NASA/ESA Hubble Space Telescope image, which is even more dramatic than fiction, captures the chaotic activity atop a pillar of gas and dust, three light-years tall, which is being eaten away by the brilliant light from nearby bright stars. The pillar is also being assaulted from within, as infant stars buried inside it fire off jets of gas that can be seen streaming from towering peaks.
Hubble Space Telescope

Hubble celebrates 20 years of awe and discovery

» go to article
This is a composite image of the most distant galaxy cluster yet detected.
Galaxy Clusters in the Young Cosmos

Record Breaking Galaxy Clusters

» go to article
Search
Astronomy Software

Solar Eclipse by Redshift

Solar Eclipse by Redshift for iOS

Observe, understand, and marvel at the solar eclipse on August 21, 2017! » more

Solar Eclipse by Redshift

Solar Eclipse by Redshift for Android

Observe, understand, and marvel at the solar eclipse on August 21, 2017! » more

The nature of dark energy

First Use of Cosmic Lens to Probe Dark Energy

Astronomers have devised a new method for measuring perhaps the greatest puzzle of our universe — dark energy. This mysterious force, discovered in 1998, is pushing our universe apart at ever-increasing speeds.
This is the Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away. Dark matter in the cluster is mapped by plotting the plethora of arcs produced by the light from background galaxies that is warped by the foreground cluster's gravitational field. Dark matter cannot be photographed, but its distribution is shown in the blue overlay. The dark matter concentration and distribution is then used to better understand the nature of dark energy, a pressure that is accelerating the expansion of the universe. The imaging data used in the natural-color photo was taken in 2002 with Hubble's Advanced Camera for Surveys.

This is the Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away. Dark matter in the cluster is mapped by plotting the plethora of arcs produced by the light from background galaxies that is warped by the foreground cluster's gravitational field. Dark matter cannot be photographed, but its distribution is shown in the blue overlay. The dark matter concentration and distribution is then used to better understand the nature of dark energy, a pressure that is accelerating the expansion of the universe. The imaging data used in the natural-color photo was taken in 2002 with Hubble's Advanced Camera for Surveys.

For the first time, astronomers using NASA's Hubble Space Telescope were able to take advantage of a giant magnifying lens in space — a massive cluster of galaxies — to narrow in on the nature of dark energy. Their calculations, when combined with data from other methods, significantly increase the accuracy of dark energy measurements. This may eventually lead to an explanation of what the elusive phenomenon really is.

"We have to tackle the dark energy problem from all sides," said Eric Jullo, an astronomer at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It's important to have several methods, and now we've got a new, very powerful one." Jullo is lead author of a paper on the findings appearing in the Aug. 20 issue of the journal Science.

Scientists aren't clear about what dark energy is, but they do know that it makes up a large chunk of our universe, about 72 percent. Another chunk, about 24 percent, is thought to be dark matter, also mysterious in nature but easier to study than dark energy because of its gravitational influence on matter that we can see. The rest of the universe, a mere 4 percent, is the stuff that makes up people, planets, stars, and everything made up of atoms.

In their new study, the science team used images from Hubble to examine a massive cluster of galaxies, named Abell 1689, which acts as a magnifying, or gravitational, lens. The gravity of the cluster causes galaxies behind it to be imaged multiple times into distorted shapes, sort of like a fun-house mirror reflection that warps your face.

Using these distorted images, the scientists were able to figure out how light from the more distant, background galaxies had been bent by the cluster — a characteristic that depends on the nature of dark energy. Their method also depends on precise ground-based measurements of the distance and speed at which the background galaxies are traveling away from us. The team used these data to quantify the strength of the dark energy that is causing our universe to accelerate.

"What I like about our new method is that it's very visual," said Jullo, "You can literally see gravitation and dark energy bend the images of the background galaxies into arcs."

According to the scientists, their method required multiple, meticulous steps. They spent the last several years developing specialized mathematical models and precise maps of the matter — both dark and "normal" — constituting the Abell 1689 cluster.

"We can now apply our technique to other gravitational lenses," said co-author Priya Natarajan, a cosmologist at Yale University, New Haven, Conn. "We're exploiting a beautiful phenomenon in nature to learn more about the role that dark energy plays in our universe."

Source: Hubblesite
» print article

Search
Astronomy Software

Solar Eclipse by Redshift

Solar Eclipse by Redshift for iOS

Observe, understand, and marvel at the solar eclipse on August 21, 2017! » more

Solar Eclipse by Redshift

Solar Eclipse by Redshift for Android

Observe, understand, and marvel at the solar eclipse on August 21, 2017! » more