An international team led by researchers at CNRS, Université Grenoble Alpes and the French Alternative Energies and Atomic Energy Commission (CEA) has challenged currently held ideas about star formation. Published in Nature Astronomy, the findings could challenge the widespread assumption that the mass distribution of a population of star-forming cores is identical to that of the stars they spawn.
In space, hidden behind the dusty veils of nebulae, clouds of gas clump together and collapse, forming the structures from which stars are born: star-forming cores. These cluster together, accumulate matter and fragment, eventually giving rise to a cluster of young stars of various masses, whose distribution was described by Edwin Salpeter as an astrophysical law in 1955.
Astronomers had already noticed that the ratio of massive objects to non-massive objects was the same in clusters of star-forming cores as in clusters of newly-formed stars. This suggested that the mass distribution of stars at birth, known as the IMF1, was simply the result of the mass distribution of the cores from which they formed, known as the CMF2. However, this conclusion resulted from the study of the molecular clouds closest to our Solar System, which are not very dense and therefore not very representative of the diversity of such clouds in the Galaxy. Is the relationship between the CMF and the IMF universal? What do we observe when we look at denser, more distant clouds?
These were the questions asked by researchers at the Grenoble Institute of Planetology and Astrophysics (CNRS/Université Grenoble Alpes) and the Astrophysics, Instrumentation and Modelling Laboratory, (CNRS/CEA/Université Paris Diderot)3 when they started to observe the active star-formation region W43-MM1, whose structure is far more typical of molecular clouds in our Galaxy than those observed previously. Thanks to the unprecedented sensitivity and spatial resolution of the ALMA antenna array in Chile, the researchers were able to establish a statistically robust core distribution over an unmatched range of masses, from solar-type stars to stars 100 times more massive. To their surprise, the distribution did not obey Salpeter's 1955 law.
It turned out that, in the W43-MM1 cloud, there was an overabundance of massive cores, while less massive cores were under-represented. These findings call into question not only the relationship between the CMF and the IMF, but even the supposedly universal nature of the IMF. The mass distribution of young stars may not be the same everywhere in our Galaxy, contrary to what is currently assumed. If this turns out to be the case, the scientific community will be forced to re-examine its calculations about star formation and, eventually, any estimates that depend on the number of massive stars, such as the chemical enrichment of the interstellar medium, the numbers of black holes and supernovae, etc.
The teams will continue their work with ALMA within a consortium of around forty researchers. Their aim is to study 15 regions similar to W43-MM1 in order to compare their CMFs and ascertain whether the characteristics of this cloud can be generalised.
Explore further:
The initial mass function
More information:
F. Motte et al, The unexpectedly large proportion of high-mass star-forming cores in a Galactic mini-starburst, Nature Astronomy (2018). DOI: 10.1038/s41550-018-0452-x
cantdrive85
1 / 5 (8) Apr 30, 2018jonesdave
3.7 / 5 (6) Apr 30, 2018Yeah, something for which you have no explanation whatsoever. Go figure.
Tuxford
1 / 5 (7) Apr 30, 2018As I have repeated for years, regions of high matter density spawn fertile sub-quantum conditions that gives rise to accelerated production of new matter. Thus, in these regions massive cores grow more quickly than less massive cores. (Let's call it 'LaViolette's Law'. LOL.)
wduckss
1 / 5 (3) Apr 30, 2018"from the total amount of starsin Milky Way, 96,15% are the stars of the classes M, K and G with low temperatures, up to ~ 6.000 K. Very small, even insignificant part of them are extremely hot, hot and warm stars, 3,85% (class O making only ~0,00003%)" http://www.svemir...Universe
About that equal distribution is the word?
granville583762
1.8 / 5 (5) Apr 30, 2018cantdrive85
1 / 5 (8) Apr 30, 2018No explanation needed for PC/EU, this is a gravity only Cosmos issue. The conjectured mass of these clouds is of little importance as there is no needed physics defying gravitational collapse. Charge density and plasma pressure are of far greater importance.
andyf
4.8 / 5 (6) Apr 30, 2018OK, what do you think has been falsified?
Where do you see anyone conjuring up anything dark and magical?
When will you wake up to the fact that you're a demented plonker?
cantdrive85
1.6 / 5 (7) Apr 30, 2018Right there above, where they state;
"To their surprise, the distribution did not obey Salpeter's 1955 law"
Bzzzzt, failed guess. But you can't blame the guy, he postulated this back before the space-age when astrophysicists still believed in their fanciful ideal ionized gases. Wait, they still do. LOL! Nothing has changed for well over half a century.
Let's see, how about 96% of your Universe.
Dark matter, everywhere you need it, but nowhere you can find it. Both dark and magical.
Dark energy, everywhere expanding space-time. Must be magical being it is expanding a fanciful non-entity, and BTW it's dark.
Black holes, scary self-cloaking gravity monsters that won't let light escape while at the same time ejecting matter across many light years in collimated jets. Clearly both magical and dark.
Like I said, 96% of your Universe is both magical and dark.
jonesdave
4.1 / 5 (9) Apr 30, 2018And what has this got to do with the totally debunked EU woo?
cantdrive85
1.6 / 5 (7) Apr 30, 2018I woke up from being a demented plonker about 15-years ago when I stopped believing in your dark and magical faerie tales. When I realized Einstein was a crank, that the BB is a creation theory put forth by a priest, and that the space sciences had devolved into pop-scf-fi stories to pander to trekkies and morons alike.
granville583762
2.3 / 5 (3) May 01, 2018It is to be found everywhere, seek it here, seek it there, but nowhere is it to be found - where O where did it get lost; found it, thank heaven for little blackholes!
From, a lone diehard darkmatter Atheist.
Sol88
1 / 5 (4) May 01, 2018Now if you give me a grant, I predict in about 10-20yrs i'll Be getting pretty close to understanding I was wrong! :)
jonesdave
4 / 5 (8) May 01, 2018Given that you still believe in electric comets, that is unlikely. In fact it is unlikely that after 20 years, or any other amount of time, you would understand anything about astrophysics or cosmology. Dark matter is demonstrable from its lensing effects:
http://scienceblo...ng-show/
Now, perhaps the EU wooists can give us their explanation, and show us the evidence for it. That was totally rhetorical, as there is nobody connected with that cult who has the ability or qualifications to be able to figure something like that out. Just a bunch of Velikovskian loons.
cantdrive85
1 / 5 (3) May 01, 2018Swell, a link to pseudoscience blog. Why don't you try some real science jonesdumb?
RealityCheck
1 / 5 (4) May 01, 2018So I will only comment on the nature of that DM. We NOW increasingly finding it in vast quantities practically everywhere we look, near and far; and that it is just *Ordinary Stuff* (in various energy/motion states) that *Previously" was too faint to 'see' (and hence the old/naive interpretations, calculations and 'problems' that earlier *incomplete* data 'allowed to sprout like weeds'; and which are still being 'parroted' as if we haven't learned anything new about the universal contents/processes since then!).
So, @jonesdave, I've never argued against DM existence; only against claims it is *exotic* stuff; and that it *only interacts gravitationally*.
Now we KNOW *Ordinary Stuff* is ALREADY there between galaxies/clusters, the motions/lensing have ordinary *trivial* explanations. No *exotica* needed. :)