In the corners of this image there are dozens of streaks going radially outward from the center of this globular cluster:
http://antwrp.gsfc.nasa.gov/apod/ap050905.html
Is this normal? I can think of three possible causes for the streaks:
1) At the center of the cluster there are explosions which eject material outward. In the vacuum of space however wouldn't the ejected matter stay as a cohesive unit, not as streaks - ie. there is no drag on moving matter in a vacuum though I suppose gravity of surrounding stars could provide the drag to rip apart the ejcted matter. If this is the case, then these explosions have to be incredibly huge to eject so much matter so far out from something with so much mass. Maybe these are the result of supernovas within the cluster.
2) The gravitational force of the cluster is pulling stars inward (ripping them apart actually) into the center of the cluster. This scenario suffers from the same problems noted in #1 above with regard to streaking in a vacuum. Also, why then aren't
all the stars sucked back into the center of the cluster? Perhaps the strekaing ones are the stars that existed prior to the formation of the cluster, and all other stars are being uniformly ejected from the cluster center.
3) Gravitational lensing of stars in the background behind the cluster. But shouldn't such lensing result in streaks that are perpendicular to these streaks?
What other possibilities are there?
Globular clusters have always been a mystery - why don't they blow themselves apart, and what's keeping them from collapsing under their own mass? How do they evolve - are the stars born there in the middle or on the fringes? How will they die - through supernovas in the middle, or by burning out in the fringes? Maybe these streaks can provide some clues.
In the corners of this image there are dozens of streaks going radially outward from the center of this globular cluster:
[url]http://antwrp.gsfc.nasa.gov/apod/ap050905.html[/url]
Is this normal? I can think of three possible causes for the streaks:
1) At the center of the cluster there are explosions which eject material outward. In the vacuum of space however wouldn't the ejected matter stay as a cohesive unit, not as streaks - ie. there is no drag on moving matter in a vacuum though I suppose gravity of surrounding stars could provide the drag to rip apart the ejcted matter. If this is the case, then these explosions have to be incredibly huge to eject so much matter so far out from something with so much mass. Maybe these are the result of supernovas within the cluster.
2) The gravitational force of the cluster is pulling stars inward (ripping them apart actually) into the center of the cluster. This scenario suffers from the same problems noted in #1 above with regard to streaking in a vacuum. Also, why then aren't [b]all[/b] the stars sucked back into the center of the cluster? Perhaps the strekaing ones are the stars that existed prior to the formation of the cluster, and all other stars are being uniformly ejected from the cluster center.
3) Gravitational lensing of stars in the background behind the cluster. But shouldn't such lensing result in streaks that are perpendicular to these streaks?
What other possibilities are there?
Globular clusters have always been a mystery - why don't they blow themselves apart, and what's keeping them from collapsing under their own mass? How do they evolve - are the stars born there in the middle or on the fringes? How will they die - through supernovas in the middle, or by burning out in the fringes? Maybe these streaks can provide some clues.