David Kirkpatrick

January 23, 2010

Beautiful space image — a rare double-tailed gas cloud

Here you go:

MSU’s Megan Donahue was part of an international team of astronomers that viewed this rare double-tailed gas cloud. Their paper on the subject is in the publication Astrophysical Journal. Photo courtesy of the Chandra X-Ray Observatory

Head below the fold for the release accompanying the image. (more…)

December 11, 2008

Beautiful image of The Tarantula Nebula

Filed under: Arts, Science — Tags: , , , , — David Kirkpatrick @ 4:03 pm

Very cool image.

Here’s the text from NASA:

A new Chandra X-ray Observatory image of the Tarantula Nebula gives scientists a close-up view of the drama of star formation and evolution. The Tarantula, also known as 30 Doradus, is in one of the most active star-forming regions in a galaxy close to the Milky Way. Massive stars in 30 Doradus are producing intense radiation and searing winds of multimillion-degree gas that carve out gigantic super-bubbles in the surrounding gas.

And, of course, the image:

Tarantula Nebula (30 Doradus):
Drama In The Heart Of The Tarantula


Credit: NASA/CXC/Penn State/L.Townsley, et al.

Found in the nearby Large Magellanic Cloud, 30 Doradus is one of the largest massive star forming regions close to the Milky Way. Enormous stars in 30 Doradus, also known as the Tarantula Nebula, are producing intense radiation and searing winds of multimillion-degree gas that carve out gigantic bubbles in the surrounding cooler gas and dust. Other massive stars have raced through their evolution and exploded catastrophically as supernovae, expanding these bubbles into X-ray-brightened superbubbles. They leave behind pulsars as beacons of their former lives and expanding supernova remnants that trigger the collapse of giant clouds of dust and gas to form new generations of stars.

At the center of 30 Doradus lies the star cluster R136 at the intersection of three of these superbubbles. However, with ages only between one and two million years old, the stars in R136 are too young to be source of the supernovae that brighten the superbubbles in X-rays. Instead, R136 is most likely just the latest cluster to form in 30 Doradus. It may be as massive as it is because these superbubbles have combined to concentrate their gas in this region and thus triggered intense star formation there.

30 Doradus is about 160,000 light years from Earth in the southern constellation of Dorado. It spans 800 light years across and is incredibly bright in many wavelengths. If it were at the distance of the Orion Nebula (1,300 light years), 30 Doradus would span the area of 60 full Moons and its optical light would be bright enough to cast shadows at night on the Earth. This latest X-ray image of 30 Doradus represents almost 114,000 seconds, or 31 hours, of Chandra observing time – three times longer than previously recorded. In this image, red represents the lower range of X-rays that Chandra detects, the medium range is green, while the highest-energy X-rays are blue.

Fast Facts for Tarantula Nebula:
Credit  NASA/CXC/Penn State/L.Townsley, et al.
Scale  Image is 24 arcmin across .
Category  Normal Stars & Star Clusters
Coordinates (J2000)  RA 05h 38m 42.9s | Dec -69° 06′ 3″
Constellation  Dorado
Observation Dates  09/21/1999 – 01/30/2006
Observation Time  32 hours
Obs. IDs  22, 5906, 7263, 7264, 62520
Color Code  Red (0.5-0.7 keV); Green (0.7-1.1 keV); Blue (1.1-2.0 keV)
Instrument  ACIS
Distance Estimate  About 160,000 light years
Release Date  December 11, 2008

August 27, 2008

Clash of galactic titans

UC Santa Barbara astronomers used the Hubble and Chandra to discover a collision of galaxy clusters.

From the release:

Collision of galaxy clusters captured by astronomers

(Santa Barbara, Calif.) – Two UC Santa Barbara astronomers are part of a team that has made a stunning discovery using the Hubble Space Telescope and Chandra X-ray Observatory, it was announced today by the National Aeronautics and Space Administration.

The capture of a collision of galaxy clusters was made by a team led by Marusa Bradac, a postdoctoral researcher and Hubble fellow in UCSB’s Department of Physics. The international team also included Tommaso Treu, assistant professor of physics at UCSB.

“It is in our view an important step forward to understanding the properties of the mysterious dark matter,” Bradac said. “Dark matter makes up five times more matter in the universe than ordinary matter. This study confirms that we are dealing with a very different kind of matter, unlike anything that we are made of. And were able to study it in a very powerful collision of two clusters of galaxies.”

Below is the complete text of the press release issued today by NASA.

(Cambridge, Mass.) – A powerful collision of galaxy clusters has been captured with NASA’s Chandra X-ray Observatory and Hubble Space Telescope. Like its famous cousin, the so-called Bullet Cluster, this clash of clusters provides striking evidence for dark matter and insight into its properties.

Like the Bullet Cluster, this newly studied cluster, officially known as MACSJ0025.4-1222, shows a clear separation between dark and ordinary matter. This helps answer a crucial question about whether dark matter interacts with itself in ways other than via gravitational forces.

This finding is important because it independently verifies the results found for the Bullet Cluster in 2006. The new results show the Bullet Cluster is not an exception and that the earlier results were not the product of some unknown error.

Just like the original Bullet Cluster, MACSJ0025 formed after an incredibly energetic collision between two large clusters in almost the plane of the sky. In some ways, MACSJ0025 can be thought of as a prequel to the Bullet Cluster. At its much larger distance of 5.7 billion light years, astronomers are witnessing a collision that occurred long before the Bullet Cluster’s.

Using optical images from Hubble, the team was able to infer the distribution of the total mass – dark and ordinary matter – using a technique known as gravitational lensing (colored in blue). The Chandra data enabled the astronomers to accurately map the position of the ordinary matter, mostly in the form of hot gas, which glows brightly in X-rays (pink).

An important difference between the Bullet Cluster and the new system is that MACSJ0025 does not actually contain a “bullet.” This feature is a dense, X-ray bright core of gas that can be seen moving through the Bullet Cluster. Nonetheless, the amount of energy involved in this mammoth collision is nearly as extreme as that found in the Bullet Cluster.

As the two clusters that formed MACSJ0025 (each almost a whopping million billion times the mass of the Sun) merged at speeds of millions of miles per hour, the hot gas in each cluster collided and slowed down, but the dark matter did not. The separation between the material shown in pink and blue therefore provides direct evidence for dark matter and supports the view that dark matter particles interact with each other only very weakly or not at all, apart from the pull of gravity.

One of the great accomplishments of modern astronomy has been to establish a complete inventory of the matter and energy content of the Universe. The so-called dark matter makes up approximately 23 percent of this content, five times more than the ordinary matter that can be detected by telescopes. The latest results with MACSJ0025 once again confirm these findings.




The international team of astronomers in this study was led by Marusa Bradac of UCSB, and Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford and Stanford Linear Accelerator Center (SLAC). Other collaborators included Tommaso Treu, UCSB; Harald Ebeling, University of Hawaii; Richard Massey, Royal Observatory Edinburgh; R. Glenn Morris, SLAC; and Anja von der Linden, and Douglas Applegate, both of Stanford. Their results will appear in an upcoming issue of The Astrophysical Journal.

Collision of clusters from the Hubble Telescope and Chandra Observatory.

Collision of clusters from the Hubble Telescope and Chandra Observatory.