How The Early Universe Got Dusty Remains A Mystery

HOW THE EARLY UNIVERSE GOT DUSTY REMAINS A MYSTERY
From Lori Stiles, UA News Services, 520-621-1877
December 2, 2004

Astronomers who think they know how the very early universe came to have so
much interstellar dust need to think again, according to new results from
the Spitzer Space Telescope.

In the last few years, observers have discovered huge quantities of
interstellar dust near the most distant quasars in the very young universe,
only 700 million years after the cosmos was born in the Big Bang.

"And that becomes a big question," said Oliver Krause of the University of
Arizona in Tucson Steward Observatory and the Max Planck Institute for
Astronomy in Heidelberg. "How could all of this dust have formed so
quickly?"

------------------------------------------------
Contact Information
Oliver Krause 520.626.1798
George H. Rieke 520.621.2832

Related Web sites
MIPS - http://mips.as.arizona.edu/mipspage/
Spitzer Space Telescope - http://www.spitzer.caltech.edu/
---------------------------------------------------

Astronomers know two processes that form the dust, Krause said. One, old
sun-like stars near death generate dust. Two, infrared space missions have
revealed the dust is produced in supernovae explosions.

"The first process takes several billion years," Krause noted. "Supernovae
explosions, by contrast, produce dust in much less time, only about 10
million years."

So when astronomers reported detecting submillimeter emission from massive
amounts of cold interstellar dust in the supernova remnant Cassiopeia A last
year, some considered the mystery solved. Type II supernovae like 'Cas A'
likely produced the interstellar dust in the very early universe, they
concluded. (Type II supernovae come from massive stars that blow apart in
huge explosions after their cores collapse.)

Krause and colleagues from UA's Steward Observatory and the Max Planck
institute in Heidelberg have now discovered that the detected submillimeter
emission comes not from the Cas A remnant itself but from the molecular
cloud complex known to exist along the line of sight between Earth and Cas
A. They report the work in the Dec. 2 issue of Nature.

Cas A is the youngest known supernova remnant in our Milky Way. It is about
11,000 light years away, behind the Perseus spiral arm clouds that are
roughly 9,800 light years away. Krause suspects that the Perseus clouds
explain why late 17th century astronomers didn't report observing the
brilliant Cas A outburst around A.D. 1680. Cas A is so close to Earth that
the supernova should have been the brightest stellar object in the sky, but
dust in the Perseus clouds eclipsed the view.

The Arizona and German team mapped Cas A at 160-micron wavelengths using the
ultra-heat-sensitive Multiband Imaging Photometer (MIPS) aboard the Spitzer
Space Telescope. These long wavelengths are the most sensitive to cold
interstellar dust emission. They then compared the results with maps of
interstellar gas previously made with radio telescopes. They found that the
dust in these interstellar clouds account for virtually all the emission at
160 microns from the direction of Cas A.

Minus the emission from this dust, there is no evidence for large amounts of
cold dust in Cas A, the team concludes.

"Astronomers will have to go on searching for the source of the dust in the
early universe," UA Steward Observatory astronomer and Regents' Professor
George Rieke said. Rieke is principal investigator for the Spitzer Space
Telescope's MIPS instrument and a co-author of the Nature paper.

"Solving this riddle will show astronomers where and how the first stars
formed, or perhaps indicate there is some non-stellar process that can
produce large amounts of dust," Rieke said. "Either way, (finding the source
of the dust) will reveal what went on at the formative stage for stars and
galaxies, an epoch that is nearly unobserved in any other way."

Authors of the Nature article, "No cold dust within the supernova remnant
Cassiopeia A," are Oliver Krause, Stephan M. Birkmann, George H. Rieke,
Dietrich Lemke, Ulrich Klaas, Dean C. Hines and Karl D. Gordon.

Birkmann, Lemke and Klaas are with the Max Planck Institute for Astronomy in
Heidelberg. Krause, Rieke, and Gordon are with the University of Arizona
Steward Observatory. Hines is with the Space Science Institute in Boulder,
Colo.

The Spitzer Space Telescope is managed for NASA by the Jet Propulsion
Laboratory in Pasadena, Calif.

For this not to be a problem, just double the age of the Universe and it goes away.
For some unknown reason, 21 billion years sounds about right.

Not quite twice the age, but close enough.
Maybe there were some really dirty Aliens out there?


Regards
Robert

"Ron" wrote in message om...
HOW THE EARLY UNIVERSE GOT DUSTY REMAINS A MYSTERY
From Lori Stiles, UA News Services, 520-621-1877
December 2, 2004

Astronomers who think they know how the very early universe came to have so
much interstellar dust need to think again, according to new results from
the Spitzer Space Telescope.

In the last few years, observers have discovered huge quantities of
interstellar dust near the most distant quasars in the very young universe,
only 700 million years after the cosmos was born in the Big Bang.

"And that becomes a big question," said Oliver Krause of the University of
Arizona in Tucson Steward Observatory and the Max Planck Institute for
Astronomy in Heidelberg. "How could all of this dust have formed so
quickly?"

------------------------------------------------
Contact Information
Oliver Krause 520.626.1798
George H. Rieke 520.621.2832

Related Web sites
MIPS - http://mips.as.arizona.edu/mipspage/
Spitzer Space Telescope - http://www.spitzer.caltech.edu/
---------------------------------------------------

Astronomers know two processes that form the dust, Krause said. One, old
sun-like stars near death generate dust. Two, infrared space missions have
revealed the dust is produced in supernovae explosions.

"The first process takes several billion years," Krause noted. "Supernovae
explosions, by contrast, produce dust in much less time, only about 10
million years."

So when astronomers reported detecting submillimeter emission from massive
amounts of cold interstellar dust in the supernova remnant Cassiopeia A last
year, some considered the mystery solved. Type II supernovae like 'Cas A'
likely produced the interstellar dust in the very early universe, they
concluded. (Type II supernovae come from massive stars that blow apart in
huge explosions after their cores collapse.)

Krause and colleagues from UA's Steward Observatory and the Max Planck
institute in Heidelberg have now discovered that the detected submillimeter
emission comes not from the Cas A remnant itself but from the molecular
cloud complex known to exist along the line of sight between Earth and Cas
A. They report the work in the Dec. 2 issue of Nature.

Cas A is the youngest known supernova remnant in our Milky Way. It is about
11,000 light years away, behind the Perseus spiral arm clouds that are
roughly 9,800 light years away. Krause suspects that the Perseus clouds
explain why late 17th century astronomers didn't report observing the
brilliant Cas A outburst around A.D. 1680. Cas A is so close to Earth that
the supernova should have been the brightest stellar object in the sky, but
dust in the Perseus clouds eclipsed the view.

The Arizona and German team mapped Cas A at 160-micron wavelengths using the
ultra-heat-sensitive Multiband Imaging Photometer (MIPS) aboard the Spitzer
Space Telescope. These long wavelengths are the most sensitive to cold
interstellar dust emission. They then compared the results with maps of
interstellar gas previously made with radio telescopes. They found that the
dust in these interstellar clouds account for virtually all the emission at
160 microns from the direction of Cas A.

Minus the emission from this dust, there is no evidence for large amounts of
cold dust in Cas A, the team concludes.

"Astronomers will have to go on searching for the source of the dust in the
early universe," UA Steward Observatory astronomer and Regents' Professor
George Rieke said. Rieke is principal investigator for the Spitzer Space
Telescope's MIPS instrument and a co-author of the Nature paper.

"Solving this riddle will show astronomers where and how the first stars
formed, or perhaps indicate there is some non-stellar process that can
produce large amounts of dust," Rieke said. "Either way, (finding the source
of the dust) will reveal what went on at the formative stage for stars and
galaxies, an epoch that is nearly unobserved in any other way."

Authors of the Nature article, "No cold dust within the supernova remnant
Cassiopeia A," are Oliver Krause, Stephan M. Birkmann, George H. Rieke,
Dietrich Lemke, Ulrich Klaas, Dean C. Hines and Karl D. Gordon.

Birkmann, Lemke and Klaas are with the Max Planck Institute for Astronomy in
Heidelberg. Krause, Rieke, and Gordon are with the University of Arizona
Steward Observatory. Hines is with the Space Science Institute in Boulder,
Colo.

The Spitzer Space Telescope is managed for NASA by the Jet Propulsion
Laboratory in Pasadena, Calif.



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Ron wrote in message
om...
HOW THE EARLY UNIVERSE GOT DUSTY REMAINS A MYSTERY
From Lori Stiles, UA News Services, 520-621-1877
December 2, 2004

Astronomers who think they know how the very early universe came to have
so much interstellar dust need to think again, according to new results
from
the Spitzer Space Telescope.

In the last few years, observers have discovered huge quantities of
interstellar dust near the most distant quasars in the very young
universe, only 700 million years after the cosmos was born in the Big
Bang.

"And that becomes a big question," said Oliver Krause of the University of
Arizona in Tucson Steward Observatory and the Max Planck Institute for
Astronomy in Heidelberg. "How could all of this dust have formed so
quickly?"

The simple answer is that the quasars aren't that far away. Redshift
doesn't always equal doppler or cosmic expansion.

Of course, the BB will eventually get another epicycle added to explain yet
another discrepancy with observation.

{snip the rest}


--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}

"greywolf42" ha scritto nel messaggio
.. .

In the last few years, observers have discovered huge quantities of
interstellar dust near the most distant quasars in the very young
universe, only 700 million years after the cosmos was born in the Big
Bang.

"And that becomes a big question," said Oliver Krause of the University
of
Arizona in Tucson Steward Observatory and the Max Planck Institute for
Astronomy in Heidelberg. "How could all of this dust have formed so
quickly?"

The simple answer is that the quasars aren't that far away. Redshift
doesn't always equal doppler or cosmic expansion.

Too simple and too logic to be accepted...

Luigi Caselli