Stream of Hydrogen Connects the Milky Way and the Magellanic Clouds
Written by Fraser Cain
If you live in the southern hemisphere, the Magellanic Clouds are a familiar sight. These are the closest, brightest examples of dwarf galaxies we can see from the Milky Way. Radio astronomers have discovered a tenuous stream of hydrogen connecting our galaxy together with the Magellanic Clouds. This stream will help astronomers calculate the motion of the Clouds. Have they been here for a long time, or are they just passing by.
The finger of hydrogen gas, called HVC306-2+230, is piercing through the disk of the Milky Way about 70,000 light-years away from our location. The exact point of contact is near the Southern Cross (you southerners know what I'm talking about).
Astronomers used to think that the Magellanic Clouds had orbited the Milky Way many times, slowly getting dismembered. But new observations from the Hubble Space Telescope showed that they're actually moving much more quickly than previously believed. Instead of orbiting the Milky Way, they might just be passing us once, never to return.
By detecting where this leading arm strikes the Milky Way, astronomers will have an easier time calculating the Clouds' trajectory.
"We think the Leading Arm is a tidal feature, gas pulled out of the Magellanic Clouds by the Milky Way's gravity," said Dr McClure-Griffiths, the research team leader from CSIRO's Australia Telescope National Facility. "Where this gas goes, we’d expect the Clouds to follow, at least approximately."
Their discovery actually strengthens the original theory, that the Clouds have been orbiting the Milky Way for a long time. Of course, the researchers caution that this isn't the final word on the subject – the flyby model still hasn't been ruled out.
But if they're right, the Magellanic Clouds will eventually merge with the Milky Way and not zoom past.
Original Source: CSIRO News Release
Filed under: Astronomy
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February 5th, 2008 at 5:04 pm
Does anyone know if ground based telescopes pick up on the part of the electromagnetic spectrum that hydrogen resonates at? Or does the atmosphere block that out?
February 5th, 2008 at 7:22 pm
this is the best unavres
February 5th, 2008 at 11:18 pm
Am I readin this right, or does the story give conflicting descriptions of what is likely to happen?
"Instead of orbiting the Milky Way, they might just be passing us once, never to return."
"Their discovery actually strengthens the original theory, that the Clouds have been orbiting the Milky Way for a long time. "
"But if they're right, the Magellanic Clouds will eventually merge with the Milky Way and not zoom past."
February 5th, 2008 at 11:59 pm
It makes far more sense to me that these dwarf galaxies are destined to merge with the milky way rather than just zoom on by. It is quite an interesting story that we still haven't been able to answer this question about them when they are so close and so large.
February 6th, 2008 at 9:05 am
I wonder if a third scenario is possible? Perhaps the Magellanic Clouds already passed through the Milky Way, leaving a trail of hydrogen in their wake?
February 6th, 2008 at 12:04 pm
I don't see the big deal. This has been known since the early 70's. Heck, it's even in Wikipedia.
February 6th, 2008 at 7:15 pm
This reminds me of the debate we had last week in my highschool physics class.
"The Universe is only 6,600 years old."
all i could do was laugh, how else could we see anything from outside our own galaxy that is millions of light-years away if the Universe was only created 6,600 years ago…. makes me wonder who their parents are going to vote for in the elections….
I don't understand how they can ignore scientific facts that are so plainly laid before them.
February 6th, 2008 at 11:38 pm
That's the worst "artist's mock-up image" for a story I've ever seen on this site. Good story though.
February 7th, 2008 at 2:13 am
If the stream is neutral hydrogen then one way to detect it is using the 21 cm spectral line. That puts it firmly in the realm of earth bound radio telescopes. It will only glow the characteristic pink/red colour if it is excited by something nearby pushing out a lot of UV. That seems not to be the case here.
February 7th, 2008 at 8:34 am
Great so now we can send electricity to other planets in those clouds that r orbiting our solar system.
I dont get how u guys say that the solar system has to be 15+ million years old – it is totally possible that one bible year = millions of years today.
February 7th, 2008 at 11:07 am
Sub: Plasma Vision of the Universe
Plasma occupies the shape of the body White dwarfs drives the Spiral flows. Search :Universal Plasma Energy Model- by V. Nanduri-IEEE-ICOPS- Space Plasmas- Conference 1991and Plasma Vision of the Universe- Book by Vidyardhi Nanduri, 1993 The sequence from any cellular Plasma source drives the White Dwarfs which in turn provides the flows to Spiral formations. The Dynamic function – DMVT process -Double Magnetic Vortex Process helps distributon of the Energy in the inter-Galactic Plane Further explanations are given in Cosmic Pot Energy-New projections sd [dot] stsci [dot] edu/astrophysical_laboratory/proceedings [dot] html. Author: Nanduri Research Papers- 2003: Cosmologystructures-New Modelling www [dot] ociw [dot] edu/ociw/symposia/series/symposium3/proceedings [dot] htm
Cosmologyvedas [dot] blogspot [dot] com/ Vidyardhi Nanduri
February 9th, 2008 at 3:43 pm
Isn't this old news, isn't it the Magellanic Stream?