Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sweeping X-ray Imaging Survey of Dying Stars is ‘Uncharted Territory'

11.10.2012
RIT astronomer Joel Kastner heads international team using the Chandra X-ray Observatory
The death throes of dying stars are the focus of a sweeping new survey using NASA’s Chandra X-ray satellite observatory.

More than two dozen astronomers have aligned their research goals to use Chandra to image a set of dying stars in the neighborhood of the Sun. The resulting X-ray images of these dying stars—called planetary nebulae—are shedding light on the violent “end game” of a Sun-like star’s life.

X-ray: NASA/CXC/RIT/J.Kastner et al.; Optical: NASA/STScI

Four planetary nebulae are shown here from the first systematic survey of these dying, Sun-like stars in the solar neighborhood using the Chandra X-Ray Observatory. X-ray emission from Chandra is colored purple and optical emission from the Hubble Space Telescope is colored red, green and blue. The nebulae are NGC 6543, also known as the Cat's Eye (top left), NGC 7662 (top right), NGC 7009 (bottom left) and NGC 6826 (bottom right).

The research team, led by Joel Kastner from Rochester Institute of Technology, won seven days of observing time with Chandra in 2011–12 to survey and image nearly two dozen relatively nearby planetary nebulae, resulting in the most comprehensive X-ray survey to date for such objects.

The same team recently won an eight-day time award with Chandra to continue its observing program, and will begin collecting new X-ray data later this year.

Both the previous and upcoming series of observations are part of the Chandra X-ray Survey of Planetary Nebulae (ChanPlaNS). Leaders in planetary nebula astronomy from seven countries joined forces to win the large Chandra observing time awards.

A planetary nebula is a dying star (recently a “red giant”) that has cast off its outer layers. The newly exposed, hot core of the star (which will eventually become a “white dwarf” star) illuminates these ejected layers, while the core’s fast winds sculpt the material into a variety of shapes. The resulting dazzling objects, bearing names like Cat’s Eye, Lemon Slice and Blue Snowball, are favorite targets of optical and near-infrared telescopes.

“Planetary nebulae have provided astrophysicists with dying star ‘laboratories’ for more than a century,” Kastner says. “They provide test beds for theories of stellar evolution and give us insight into the origin of heavy elements in the universe and on Earth. Yet we still don’t fully understand why they take on such a dazzling variety of shapes.”

The widespread debate among astrophysicists concerning the planetary nebula shaping process led Kastner and postdoctoral fellow Rodolfo Montez Jr. to organize their colleagues to request a large allocation of X-ray satellite observing time to investigate the processes of stellar death and wind collisions in X-rays.

“An X-ray survey of this kind is completely uncharted territory in the planetary nebula world,” Kastner adds. “Astronomers working in this area agreed that we need large quantities of time to look at as many planetary nebulae as possible, specifically with Chandra.”

His team is using X-ray imaging to look “under the hood” of planetary nebulae. X-rays cut through the illuminated gas and dust, allowing astronomers to investigate the last tens of thousands of years of history of the dying star that threw off its outer sheaths.

“With Chandra’s exceptional ‘X-ray vision,’ we can detect the million-degree plasma inside the discarded shells and probe the energies of the stellar winds that shape them,” Kastner says.

In the initial phase of the project, the team collected data for 35 planetary nebulae—21 previously unobserved and 14 pulled from Chandra archival data—all within roughly 5,000 light years of the Sun. The recent award will bump the study to a total of 59 objects from among the roughly 120 planetary nebulae identified within this distance.

“Because they all just happen to lie relatively nearby, we think this group of objects is fairly representative of planetary nebulae in general,” Kastner says.

The findings will give theorists material to refine models describing mechanisms that shape planetary nebulae, especially the potential influence of a stellar or even a planetary companion to the dying star.

“The ChanPlaNS study provides fresh new insights into the last, dying gasps of stars like the Sun,” Kastner says. “We expect it will clarify what planetary nebulae can tell us about binary star astrophysics and stellar wind interactions.”

Early findings from the study include:

• The collision of the fast wind from the exposed core with the ejected atmosphere causes shock waves that produce the diffuse X-ray emission seen in about 30% of the full sample (and in the four provided images). The Chandra survey data shows that most planetary nebulae with diffuse X-ray emission have sharp-rimmed shells that were ejected less than 5,000 years ago; these compact inner shells are surrounded by fainter halos of material ejected tens of thousands of years earlier.

• About half of the planetary nebulas in the Chandra study show point-like X-ray sources at their central stars. Many of these point sources show high-energy X-rays that may emanate from a previously undetected companion to the central star. This supports theories asserting that double stars are responsible for the nonspherical shapes of many planetary nebulas.

These and other results from the initial phase of the project were reported in the August issue of The Astronomical Journal. Kastner and Montez are the lead authors of the paper, entitled “The Chandra X-ray Survey of Planetary Nebulae (CHANPLaNS): Probing Binarity, Magnetic Fields and Wind Collisions.” Montez, one of the first recipients of a Ph.D. from RIT’s Astrophysical Sciences and Technology, is now a postdoctoral fellow at Vanderbilt University.

Susan Gawlowicz | EurekAlert!
Further information:
http://www.rit.edu

More articles from Physics and Astronomy:

nachricht Quantum optical sensor for the first time tested in space – with a laser system from Berlin
23.01.2017 | Ferdinand-Braun-Institut Leibniz-Institut für Höchstfrequenztechnik

nachricht SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

Quantum optical sensor for the first time tested in space – with a laser system from Berlin

23.01.2017 | Physics and Astronomy

The interactome of infected neural cells reveals new therapeutic targets for Zika

23.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>