Evidence of fast pebble growth near condensation fronts in the HL Tau protoplanetary disk

[ScienceRocks]

U of T astrophysicists offer proof that famous image shows forming planets EurekAlert Science News
1505.00882 Evidence of fast pebble growth near condensation fronts in the HL Tau protoplanetary disk

Evidence of fast pebble growth near condensation fronts in the HL Tau protoplanetary disk

Water and simple organic molecular ices dominate the mass of solid materials available for planetesimal and planet formation beyond the water snow line. Here we analyze ALMA long Baseline 2.9, 1.3 and 0.87mm continuum images of the young star HL Tau, and suggest that the emission dips observed are due to rapid pebble growth around the condensation fronts of abundant volatile species. Specifically, we show that the prominent innermost dip at 13AU is spatially resolved in the 0.87mm image, and its center radius is coincident with the expected mid-plane condensation front of water ice. In addition, two other prominent dips, at distances of 32 and 63 AU, cover the mid-plane condensation fronts of pure ammonia or ammonia hydrates and clathrate hydrates (especially with CO and N2) formed from amorphous water ice. The spectral index map of HL Tau between 1.3 and 0.87mm shows that the flux ratios inside the dips are statistically larger than those of nearby regions in the disk. This variation can be explained by a model with two dust populations, where most of solid mass resides in a component that has grown into decimeter size scales inside the dips. Such growth is in accord with recent numerical simulations of volatile condensation, dust coagulation and settling.

wow This pretty much confirms a shit load of planetary formation theories.

 

[Old Rocks]

B..b...b..but them thar pointy headed commie scientists don't know nuthin'!

 

[CrusaderFrank]

All we have to do now is sit back and watch the molecular ice form cells....

Anytime now

 

[ScienceRocks]

All we have to do now is sit back and watch the molecular ice form cells....

Anytime now

And you'd rather us not as crawling back into the tree is more important! Learning about 99.99999999999999999999999999999999% of everything else isn't important to people like you and I find that sad.

 

[CrusaderFrank]

All we have to do now is sit back and watch the molecular ice form cells....

Anytime now

And you'd rather us not as crawling back into the tree is more important! Learning about 99.99999999999999999999999999999999% of everything else isn't important to people like you and I find that sad.

I find these thread interesting, I find OR rather boring and predictable

 

[ScienceRocks]

All we have to do now is sit back and watch the molecular ice form cells....

Anytime now

And you'd rather us not as crawling back into the tree is more important! Learning about 99.99999999999999999999999999999999% of everything else isn't important to people like you and I find that sad.

I find these thread interesting, I find OR rather boring and predictable

So I am boring and predictable for supporting the advancement of science and human knowledge. lol

 

[Mad Scientist]

A "shitload" is right.

 

[ScienceRocks]

It's pretty much a direct observation of planets forming by clumping together from a few sand grains to rocks and onto boulders, etc. Real life! As the object gets bigger the gravity increases allowing for it to pull more stuff within its path in.