Astrophysicists identify missing fuel for galactic star formation

Aug 25, 2011
This diagram shows the large-scale flows of gas in the Milky Way halo of faint stars and hot gas. Using the Hubble Space Telescope's Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph, Nicolas Lehner and Chris Howk at the University of Notre Dame were able to directly constrain the distance of the fast-moving ionized clouds responsible for flows of gas in the Milky Way halo. The invisible clouds were detected by finding their absorption signature in the ultraviolet spectra of distant background halo stars. The researchers found that the clouds are reservoirs of gas that enable stars to continue to form in the Milky Way. Without the replenishment from recycled gas and infalling extragalactic material, stars would have stopped forming in the Milky Way a long time ago. This study also suggests the clouds slow down as they approach the Milky Way. Credit: NASA, ESA, and N. Lehner and C. Howk (University of Notre Dame)

(PhysOrg.com) -- The Milky Way will have the fuel to continue forming stars, thanks to massive clouds of ionized gas raining down from its halo and intergalactic space. This is the conclusion of a new study by Nicolas Lehner and Christopher Howk, faculty in the Department of Physics at the University of Notre Dame. Their report, "A Reservoir of Ionized Gas in the Galactic Halo to Sustain Star Formation in the Milky Way," will be published in Science tomorrow (Aug. 26).

Using the Spectrograph, one of the newest instruments on the NASA/ESA , these researchers measured for the first time the distances to fast-moving clouds of ionized gas previously seen covering a large fraction of the sky. These fast-moving clouds reside in the distant reaches of the and contain huge quantities of gas.

The Milky Way would rapidly change its gas into stars if no supply of new matter were available to replenish the gas. Astronomers have hypothesized that the ionized fast-moving gas clouds could be this reservoir of gas, but it was not known if they were interacting with the Milky Way.

"Our findings explain why the Milky Way can keep having ," Lehner says. "Knowing the distances to these clouds tells us where the gaseous fuel is for forming stars over billions of years."

Gas clouds can be identified and studied because elements in the cloud absorb small amounts of the light from a star or other as it passes through a cloud on its way to the Earth. The characteristic "fingerprint" left in the spectrum allows astronomers to determine the properties of the gas.

Star Formation in the Milky Way

Earlier studies of these fast-moving ionized clouds used light from , which are too far away to mark the clouds' locations. To solve the problem, Lehner and Howk identified 27 stars around the Milky Way, whose distances were known, and used the Hubble to take line-of-sight readings of light coming from them.

Results from the stellar sample showed the ionized clouds largely resided in the Milky Way's halo. The authors concluded that these flows of ionized gas are within about one Galactic radius (40,000 light years) of Earth. The new Hubble observations revealed the presence of in half the stellar sample, comparable to the fraction observed toward more distant quasars.

The are not uniformly distributed around the Galaxy, but rather collected in different areas. They cover only part of our Galactic sky, analogous to the partial coverage of the sky on a partly cloudy day on Earth. This research also confirmed models that predicted gas falling into the Milky Way slows as it approaches. Clouds closer to the Galaxy seem to have been decelerated and do not move as fast as those farther away, much like a meteorite slowing as it enters the Earth's atmosphere.

"We know now where is the missing fuel for Galactic star formation." Lehner concludes. "We now have to learn how it got there."

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HannesAlfven
2 / 5 (4) Aug 25, 2011
There is a problem with inferring velocity from the redshifts of the interstellar plasma ...

The work of radio astronomer Gerrit Verschuur demonstrates that critical ionization velocities of the universe's most common elements at 50 km/s, 35 km/s, 13 km/s and 5 km/s (or thereabouts) also populate the all-sky surveys of HI hydrogen (the 21-cm wavelength).

For instance, this becomes an obvious problem with regards to the anomalous "high-velocity clouds" -- which, given their apparent location, should not be moving at 35 km/s.

The CIV's occur when charged particles are moving so fast that they ionize any neutral gas which they slam into. The CIV is a function of the atomic composition of the neutral gas which they slam into, and the most common elements of the universe tend to bin into these four CIV values.

To look at the redshifts of the plasma and simply infer a velocity, ignoring the CIV's, would seem to ignore the inherent anomalies of doing so.
omatumr
1 / 5 (8) Aug 25, 2011
The Milky Way will have the fuel to continue forming stars, thanks to massive clouds of ionized gas raining down from its halo and intergalactic space, unless


The egg gave birth to the chicken: Hydrogen is a neutron decay product coming from the giant neutron star at the center of the galaxy.

A member of the neutron repulsion group recently assembled this web page [1] of experimental observations and manuscripts on neutron repulsion, the greatest known source of nuclear energy.

1. http://www.neutro...hes.html

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
yyz
4.8 / 5 (6) Aug 25, 2011
"To look at the redshifts of the plasma and simply infer a velocity, ignoring the CIV's, would seem to ignore the inherent anomalies of doing so."

Hannes, again you misstate that "important astrophysics" are being ignored. Any specifics?

The HubbleSite has a brief note on this finding: http://hubblesite...2011/26/

...as well as the original Notre Dame PR: http://newsinfo.n...rmation/

Accretion of material from the IGM onto the MW disk is a well known observational fact, Verschuur's interpretations notwithstanding.

Why isn't Verschuur a vocal and stalwart advocate for Plasma Cosmology, given that you've stated it's basic principles can be grasped with a middle-school science education? What about your other hero Chip Arp? He has a PhD is astrophysics yet does not advocate or promote this PU nonsense. Why is that Hannes? Do they not think "out of the box"?
dub1
1 / 5 (2) Aug 26, 2011
Missing matter popping up again. A little less dark matter (fudge) by the day it seems.
kevinrtrs
1.3 / 5 (15) Aug 26, 2011
Will one of the intrepid astronomers please stand up and fully explain how stars form from gas clouds?
I'm just a bit puzzled since here there's a lot of talk of stars forming as if they have already confirmed rock solidly that stars can form from gas clouds. Just where does the magic happen that defies the most basic laws of physics?
As far as I know, there's no official recognition that stars do indeed form from clouds of gas. Perhaps someone can correct me on that?
FrankHerbert
Aug 26, 2011
This comment has been removed by a moderator.
yyz
4.6 / 5 (9) Aug 26, 2011
"Will one of the intrepid astronomers please stand up and fully explain how stars form from gas clouds?"

Why do you even care what others think kev? You've got ALL the in answers to your questions in your 2000 year old "science" book.

.....and quit trolling. It not very christian, ya know.
omatumr
1 / 5 (9) Aug 26, 2011
Missing matter popping up again. A little less dark matter (fudge) by the day it seems.


Making fudge has been profitable science for four decades, since it was decided in 1971 to use Lysenko-type [1] science, the Bilderberg solar model of Earths heat source [2] and "anthropogenic climate change" as the common enemy to unite nations, end the space race, and avoid global nuclear war [3,4].

I hope to update this review of the deep roots of Climategate [5] today.

1. Skeptics dictionary, Lysenkoism

http://www.skepdi...nko.html

2. O. Gingerich and C. De Jager, The Bilderberg solar model, Solar Physics 3, 5-25 (1968)

http://adsabs.har....3....5G

3. Claud Lafleur, No More Dreams, Mr. President

http://claudelafl...ams.html

4. PBS American Experience, The Nixon Visit (February 21-28, 1972)

http://www.pbs.or...xon.html

5. http://dl.dropbox...oots.pdf
Nik_2213
3 / 5 (2) Aug 26, 2011
Given the quantity and mass of these clouds in the galactic halo, the accepted mass distribution curve may need to be tweaked. IMHO, it is a long way from falsifying 'Dark Matter', but it may be shifting the percentages.
yyz
5 / 5 (1) Aug 26, 2011
"IMHO, it is a long way from falsifying 'Dark Matter', but it may be shifting the percentages."

But Nik, we know from several lines of evidence that DM is largely (98% ) composed of *non-baryonic* matter, and that really leaves out accreting gas clouds on the disk of our galaxy (the aforementioned HVCs). And remember, we have seen many local and distant examples of galaxies accreting mass directly from the IGM for a few years now.
Robert_Wells
3.4 / 5 (5) Aug 27, 2011
I hate you kevin.


after reading kevin's posts for a long while now i've been slowly building to this, as i was reading his above post i thought to myself, i hate this guy sometimes, i scroll down and looks as if you beat me to it.

*tips hat*

kevin, if it is knowledge you seek then please make an attempt to learn.