Mysterious molecules in space

Jul 29, 2014
This graph shows absorption wavelength as a function of the number of carbon atoms in the silicon-terminated carbon chains SiC_(2n+1)H, for the extremely strong pi-pi electronic transitions. When the chain contains 13 or more carbon atoms - not significantly longer than carbon chains already known to exist in space - these strong transitions overlap with the spectral region occupied by the elusive diffuse interstellar bands. Credit: D. Kokkin, ASU

Over the vast, empty reaches of interstellar space, countless small molecules tumble quietly though the cold vacuum. Forged in the fusion furnaces of ancient stars and ejected into space when those stars exploded, these lonely molecules account for a significant amount of all the carbon, hydrogen, silicon and other atoms in the universe. In fact, some 20 percent of all the carbon in the universe is thought to exist as some form of interstellar molecule.

Many astronomers hypothesize that these are also responsible for an observed phenomenon on Earth known as the "diffuse interstellar bands," spectrographic proof that something out there in the universe is absorbing certain distinct colors of light from stars before it reaches the Earth. But since we don't know the exact chemical composition and atomic arrangements of these mysterious , it remains unproven whether they are, in fact, responsible for the diffuse interstellar bands.

Now in a paper appearing this week in The Journal of Chemical Physics, from AIP Publishing, a group of scientists led by researchers at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. has offered a tantalizing new possibility: these mysterious molecules may be silicon-capped hydrocarbons like SiC3H, SiC4H and SiC5H, and they present data and theoretical arguments to back that hypothesis.

At the same time, the group cautions that history has shown that while many possibilities have been proposed as the source of diffuse interstellar bands, none has been proven definitively.

"There have been a number of explanations over the years, and they cover the gamut," said Michael McCarthy a senior physicist at the Harvard-Smithsonian Center for Astrophysics who led the study.

Molecules in Space and How We Know They're There

Astronomers have long known that interstellar molecules containing carbon atoms exist and that by their nature they will absorb light shining on them from stars and other luminous bodies. Because of this, a number of scientists have previously proposed that some type of interstellar molecules are the source of diffuse interstellar bands—the hundreds of dark absorption lines seen in color spectrograms taken from Earth.

In showing nothing, these dark bands reveal everything. The missing colors correspond to photons of given wavelengths that were absorbed as they travelled through the vast reaches of space before reaching us. More than that, if these photons were filtered by falling on space-based molecules, the wavelengths reveal the exact energies it took to excite the electronic structures of those absorbing molecules in a defined way.

Armed with that information, scientists here on Earth should be able to use spectroscopy to identify those interstellar molecules—by demonstrating which molecules in the laboratory have the same absorptive "fingerprints." But despite decades of effort, the identity of the molecules that account for the diffuse interstellar bands remains a mystery. Nobody has been able to reproduce the exact same absorption spectra in laboratories here on Earth.

"Not a single one has been definitively assigned to a specific molecule," said Neil Reilly, a former postdoctoral fellow at Harvard-Smithsonian Center for Astrophysics and a co-author of the new paper.

Now Reilly, McCarthy and their colleagues are pointing to an unusual set of molecules—silicon-terminated carbon chain radicals—as a possible source of these mysterious bands.

As they report in their new paper, the team first created silicon-containing carbon chains SiC3H, SiC4H and SiC5H in the laboratory using a jet-cooled silane-acetylene discharge. They then analyzed their spectra and carried out theoretical calculations to predict that longer chains in this family might account for some portion of the diffuse interstellar bands.

However, McCarthy cautioned that the work has not yet revealed the smoking gun source of the diffuse interstellar bands. In order to prove that these larger silicon capped are such a source, more work needs to be done in the laboratory to define the exact types of transitions these molecules undergo, and these would have to be directly related to astronomical observations. But the study provides a tantalizing possibility for finding the elusive source of some of the mystery absorption bands—and it reveals more of the rich molecular diversity of space.

"The is a fascinating environment," McCarthy said. "Many of the things that are quite abundant there are really unknown on Earth."

Explore further: Organic conundrum in Large Magellanic Cloud

More information: The Journal of Chemical Physics, July 29, 2014. DOI: 10.1063/1.4883521

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Elmo_McGillicutty
1.5 / 5 (8) Jul 30, 2014
There are no mysterious molecules. These are frequencies that nature can not make. All of those frequencies shown in the diagram are determined by the circumference of fundamental particles. Because of the fine structure constant, some circumferences can not exist. Therefore some light frequencies do not naturally exist. There are many of them. If you want to get someones attention.....don't transmit a physical constant, transmit on one of these frequencies. And by the way.....there is no mystery about the fine structure constant. I can tell you exactly where and why it comes from.
ViperSRT3g
5 / 5 (4) Jul 30, 2014
And by the way.....there is no mystery about the fine structure constant. I can tell you exactly where and why it comes from.

Please elaborate.
Elmo_McGillicutty
2.5 / 5 (8) Jul 30, 2014
Certainly. But first I must explain what matter is and how it makes light, which nobody seems to understand. All matter is moving, confined charge. Charge has to move at the speed of light, and it must accelerate. How is that done......the speed of light and yet still accelerate? Easy...you move it in a circular path. It has the shape of the stripe on a hula hoop. The structure is the stripe. not the hoop. The surface of the hoop is where the stripe can travel and still be stable and exist for billions of years. If the charge is negative, the stripe rotates to the left, positive, it rotates to the right. In a free rest electron, the radius of the hoop is about .4 picometers. This is big R. The radius of the cross section of the hoop is about E-100 meters, little r. There is a R/r ratio that must be kept. Now the charge is distributed evenly around the stripe, no voltage nodes. But the charge is moving and that's current. Current not caused by a voltage potential....but by angular momentum. The current in a free rest electron is about 18-20 amps. This current causes a magnetic moment in the center of the hoop. The magnetic field comes out of the center and envelopes the stripe and back to the center, holding the charge on the stripe path. There is no radiation. There is neither a change in voltage or current. It's a steady current circuit. This magnetic moment is controlled by the current....and the current is controlled by angular momentum of the charge.....the angular momentum is controlled either by the velocity of charge or the length of the radius R(because R determines area). The velocity does not change, that leaves R. R goes up and down according to energy state. Fundamental particles expand and contract in proportion to their energy state. For a particle to be stable, the product of the electrical energy and the magnetic energy must equal plank's constant. There are only certain R values that give stable paths for charge to satisfy plank's constant with the proper R/r ratios. That is the fine structure constant. The fine structure constant controls what value of R is to balance energy and remain stable. Most interaction between particles is local with electric and magnetic fields. Light is a long distance interaction. This is getting long.....I will stop here and see if your still interested.
Dr_toad
Jul 30, 2014
This comment has been removed by a moderator.
Whydening Gyre
5 / 5 (1) Jul 30, 2014
I am... Following my own thoughts on "gyres"...
Gonna have to dumb it down some, tho. I'm an artist, not math whiz...

All matter is moving, confined charge. Charge has to move at the speed of light, and it must accelerate. How is that done..


Slow it down, coast and accelerate. An oscillator.

Elmo_McGillicutty
1 / 5 (5) Jul 30, 2014
Ok Mr. Gyre. By "gyres", I assume you mean gyroscopes. Being an artist.....you're really gonna like this to see how elegant our environment is. It might be confusing at first, because physics is so wrong today. The charge is moving at a constant speed of light, but it is constantly changing direction....so it is accelerating. It is not an oscillator in the common sense. Oscillators generate AC(alternating currents or voltages or both). These devices(particles) are DC dynamos(DC steady current only...with a voltage of one electron charge evenly around the hoop). The charge produces a STATIC electric field and a STEADY magnetic field. Lets stop the electron from spinning. There will be no magnetic field. The electric field lines from one side hit the field lines from the other side. These are pushing the ring apart. And a spec of charge right next to another spec.....pushes everything apart. All the charge is repulsing itself. The charge ring would explode. Now start spinning the charge ring. A magnetic moment and field starts to develop in the center of the hoop or ring. All of the magnetic field lines are inside the ring. As the charge accelerates and the magnetic field builds up, the charge starts to rotate on the ring surface. When the charge reaches the speed of light, the magnetic field pinches and equals the electric field and plank's constant is met. Also....as the charge is rotating once around small r as it rotated once around big R. This is the difference between mechanical angular momentum(MAM) and charge angular momentum(CAM). With MAM one usually adjust the speed of rotation, because R and mass is hard to vary in mechanical systems. But with CAM, the speed is constant and the big R and the little r vary in proportion with plank's constant to adjust to the energy levels and keep it stable. Plank's constant and multiples thereof is the only energy levels with the proper R/r ratios(which is CAM) for stability. This is the electron low level state, N=1. I must explain fields, before I explain light. Let's take a break. Any questions?
Uncle Ira
4.2 / 5 (5) Jul 30, 2014
@ Elmo-Skippy. Are you on the drugs? Or have the mental condition?

Maybe you should get one the peoples there who help take care of you give your postums a peek before you postum. That way maybe you won't get your feelings hurt by somebody here who doesn't understand what a brilliant crankpot you are.
Dr_toad
Jul 30, 2014
This comment has been removed by a moderator.
Whydening Gyre
not rated yet Jul 31, 2014
Ok Mr. Gyre. By "gyres", I assume you mean gyroscopes.

Nope, I meant entropic vortices.
The charge is moving at a constant speed of light, but it is constantly changing direction....so it is accelerating.

The directional change is a way of governing the acceleration?

It is not an oscillator in the common sense. Oscillators generate AC(alternating currents or voltages or both). These devices(particles) are DC dynamos(DC steady current only...with a voltage of one electron charge evenly around the hoop).

The charge state is essentially dynamic, not static, so it has to be "managed" to maintain it's static "appearance"...
Via that directional change? Charge is Kinetic in nature?
Whydening Gyre
5 / 5 (1) Jul 31, 2014
Since anything and everything seems to befuddle the cretins that frequent the place, Ira, you got a good dirty rice recipe? We might as well talk about something real, you know.. ;)

Dr. T.
Givin' up bourbon for saki?
SnowballSolarSystem _SSS_
not rated yet Aug 02, 2014
Why don't we see these predicted compounds in presolar grains within chondrites?