PDA

View Full Version : XMM-Newton Discovers Strange-Shaped Supernova Remnant



Fraser
2008-Jun-11, 11:40 PM
XMM-Newton has just released this beautiful image of a supernova remnant and its companion neutron star. To be more accurate, it didn't "discover" the object, remnant G350.1-0.3 had previously been mistaken to be a distant galaxy. The X-ray observatory has reclassified the object as a Milky Way binary system with one neutron star and the [...]

More... (http://www.universetoday.com/2008/06/11/xmm-newton-discovers-strange-shaped-supernova-remnant/)

iantresman
2008-Jun-12, 01:29 PM
Looks like the classic shape of a unipolar generator (homopolar generator or Faraday disk), see for example, the similarity with the shape of the pulsar in the crab nebula (http://www.plasma-universe.com/index.php/Unipolar_inductor)
http://imgsrc.hubblesite.org/hu/db/2002/24/images/a/formats/small_web.jpg

Compared with the Universe Today article (http://www.universetoday.com/2008/06/11/xmm-newton-discovers-strange-shaped-supernova-remnant/) image:
http://www.universetoday.com/wp-content/uploads/2008/06/supernova_remnant1.jpg

trinitree88
2008-Jun-12, 02:53 PM
Fraser. The work of M.J. Kesteven and J.L Caswell in Australia on supernova remnants clearly delineates barrel morphology for most of them..(Astronomy & Astrophysics)...see:http://adsabs.harvard.edu/full/1987A&A...183..118K

So, they don't expand equally in all directions. pete

Jerry
2008-Jun-17, 02:28 AM
Angular momentum is clearly an issue...which means the viewing angle during a supernova event is likely an important parameter to consider when estimating the magnitude of the event.

trinitree88
2008-Jun-17, 04:44 PM
Angular momentum is clearly an issue...which means the viewing angle during a supernova event is likely an important parameter to consider when estimating the magnitude of the event.

Jerry. Exactly. Which is what I said to conclude my first talk at Vassar, in November of 92. "Parity, Pulsars and Supernova Remnants".AAPT Meeting. Inverse square law only holds exactly for spheres. Supernova remnants are'nt spherical, and the recent modification of the face-on/ vs /edge-on Fisher-Tully relationship for rotation-luminosity means two of the legs in the standard candles to calibrate the universe scale have changed, and there should be a correction for the Cepheid period-luminosity as well depending on viewing angle.

pete

antoniseb
2008-Jun-17, 05:01 PM
Looks like the classic shape of ... of the pulsar in the crab nebula (http://www.plasma-universe.com/index.php/Unipolar_inductor)

Yes, no question. Amazing that the orientaiton angle and age are almost exactly the same too.

Betsy3491
2008-Jun-17, 10:19 PM
Will it become more spherical with time?

trinitree88
2008-Jun-18, 03:23 PM
Will it become more spherical with time?

Betsy. That depends on two things. The distribution of momentum in the original blast wave, and the homogeneity of the circumblast medium. If the medium is lumpy, the remnant gets quite distorted. If there is a geometry to it, it will show as a light echo (SN1987a). If there has been a relatively recent supernova in the immediate vicinity, then the ambient interstellar medium will be pretty much empty (like the Local Bubble we live in)...and it will expand as a barrel with poles, and a radial symmetry with a longitudinal axis. Most remnants imaged are barrels. When the expansion slows to ~ 25 km/sec, it will generate mostly microwaves as it rams into the interstellar medium (Eli Dwek, NASA Greenbelt, MD)


pete

see:http://www.spitzer.caltech.edu/Media/happenings/20060714/