Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

With computers, astronomers show predicted present day distribution of elusive first stars

13.12.2006
With the help of enormous computer simulations, astronomers have now shown that the first generation of stars –– which have never been observed by scientists –– should be distributed evenly throughout our galaxy, deepening the long-standing mystery about these missing stellar ancestors. The results are published in this week's issue of the Astrophysical Journal.

The problem is that despite years of looking, no one has ever found any of these stars. "Many astronomers thought this was because the stars without heavy elements were hidden from us," said Evan Scannapieco, first author and a postdoctoral fellow at the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara. "Because our galaxy formed from the inside out, the idea was that these very old stars would all be near the center. But the center of Milky Way is extremely crowded with dust and newer stars, making it very hard to detect individual old stars in this environment."

This earliest generation of stars should look very different from later-forming stars like the Sun; yet so far, no one has detected a survivor from this primordial population. One of the long-standing explanations for this discrepancy was that these stars might all be contained in regions near the center of the Milky Way, where they are very hard to observe. The results of the new study make that explanation unlikely.

Oxygen, carbon, and most of the elements we encounter every day on Earth were made in stars, rather than during the Big Bang. "But these heavy elements are made in the centers of stars and remain buried under the gas at the surface until the stars die and explode, so what you see when you look at a star are the elements that were present when it was born," said Brad K. Gibson, co-author and chair of the Department of Theoretical Astrophysics at the University of Central Lancashire in Britain. "This means that the stars still living from this first generation should continue to show no heavy elements."

Carrying out a detailed simulation of the formation of the Milky Way, the research group constructed not only the history of where stars formed over time, but the chemical composition of the gas out of which these stars formed. "We found that while the very oldest stars all end up near the center of the Milky Way, it takes a long time for heavy elements to enrich the gas that is further out," said co-author Daisuke Kawata, a scientist with the Carnegie Observatories in Pasadena, California. "This means that while the oldest stars all end up near the center of the galaxy, plenty of stars that contain only primordial elements are formed at later times throughout the galaxy. These primordial stars should be everywhere."

Because the stars forming in the Milky Way suburbs are easily detectable with present day telescopes, there must be some other reason that the remnants of this primordial generation didn't survive. "It could be that they were all high-mass stars, which would not have lived long enough to still be around, or there could be another twist to the story that we haven't yet figured out," said co-investigator Chris Brook, a scientist with the University of Washington. "Whatever the answer, it's clear that studies of the outskirts of our galaxy will have lots more to tell us about this remarkable, missing generation."

Gail Gallessich | EurekAlert!
Further information:
http://www.ia.ucsb.edu

More articles from Physics and Astronomy:

nachricht Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

nachricht Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>