HST movie of Crab Nebula Pulsar

AgentB
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Topic 202452
Mike Hewson
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Thanks for showing us

Thanks for showing us this.

These are amazing pictures. Firstly because of the technological effort to get them and secondly for the thing itself as viewed. The ripples of material being blasted outwards by intense radiation is epic. Imagine the power to do that. That material used to be inside the star before it blew up. One tends to think of neutron stars as merely spinning tops giving the odd radio blip, but that signal is a tiny fraction of the total energy output. It hoses the district with high energy photons and who knows what else. No wonder the neighborhood just glows.

{ It initially confused me that the bright source just below center of view is the neutron star, where clearly the center of the circular ripple pattern is above that. The explanation is simple. The plane in which the ripples appear - essentially produced by virtue of the geometry of the system with respect to Earth - is offset from the star. That is : the pulsar is not in the centre of that plane. A reasonable analogy here is a rainbow. A rainbow is a particular group of water molecules, within some larger volume, that by the processes of diffraction etc are highlighted at some viewing position. }

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

AgentB
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Mike Hewson wrote:Thanks for

Mike Hewson wrote:

Thanks for showing us this.

These are amazing pictures.

The HST site has a couple of these and the previous "classic" for this was here but that was "static" but worth downloading and looking around the "debris field"

Quote:
It initially confused me that the bright source just below center of view is the neutron star, where clearly the center of the circular ripple pattern is above that. The explanation is simple. The plane in which the ripples appear - essentially produced by virtue of the geometry of the system with respect to Earth - is offset from the star.

I also looked at that too, and as you say there it like a cloud layer what looks to be above the pulsar, if you look there is a smaller little cloud being illuminated below the pulsar.

I tried to do some calculations to get some scale of the image - its about a light year across which roughly matches the current estimates that the total nebula size is around 13 ± 3 ly across.  Source

It's a little monster, putting out 75000 times the energy of our sun!

edit: life as a charged particle would be one mighty roller-coaster out there.

Mike Hewson
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AgentB wrote:I also looked at

AgentB wrote:
I also looked at that too, and as you say there it like a cloud layer what looks to be above the pulsar, if you look there is a smaller little cloud being illuminated below the pulsar.

The appearance needs to be considered in the presence of the context within which the supernova went off ie. why does the nebula overall look like a splattered egg. Here's a short list that comes to mind :

- what was the ( distant ) surrounds of the progenitor star, say interstellar gas density that varies with position ? That in turns depends upon the history of the neighborhood. This includes atomic/molecular type. It's not all hydrogen and helium. Indeed supernovae are famous for producing and getting heavier elements into play. More massive species are harder to move about for a given push.

- what is the third dimension scale ? Or how do we assess distance along our line of sight, what is in front/behind of what etc ..... 

- many supernova are asymmetric in their explosion ie. not a spherical wavefront.

- did the neutron star gets a sizeable translation kick and thus has moved substantially from the origin over the last 1000 years.

- magnetic effects ( consider as time delayed electric forces ) are generally non-linear and chaotic in such a beast.

- instability in the wavefront propagation that causes irregular boundaries. 

- beaming/virtual effects. For instance when objects are moving away from us, they have a frequency shift to lower ( Doppler ) which may subtract from the overall Illuminati luminescence at a given frequency band. Necessarily that implies other bands with higher frequencies shift into the detection band and so overall one needs to know the total spectrum to assess how that works. Vice versa for going towards. There is some ( other ) relativistic reasoning applying here too.

AgentB wrote:
I tried to do some calculations to get some scale of the image - its about a light year across which roughly matches the current estimates that the total nebula size is around 13 ± 3 ly across.  Source

The features are detectably changing over the course of weeks and thus must be propagating at a fair fraction of light speed, for reasonable choices of material. The Hubble magnification limits will place bounds on feature size too. Mind you feature changes don't necessarily equate to bulk matter movement. The speed of sound is 300 m/s but that is the energy transport rate, not a 300 m/s wind !

AgentB wrote:

It's a little monster, putting out 75000 times the energy of our sun!

edit: life as a charged particle would be one mighty roller-coaster out there.

I find science fact far more interesting than science fiction. Reality can boggle me just fine, thank you.

Speaking of which I have taken the plunge and become a member of the American Physical Society. A joining fee plus a couple of online subscriptions totals about $400 AUD per annum. Not cheap. But the kids have left home now and so I'm more flush with funds these days. Anyway I have chosen to get current and archival access to Phys Rev Letters and some associated publications that they produce. I get to read the original submissions from the modern greats of the physics field.

Today I'm looking at a paper, from work done in the mid 1980's, that demonstrates the random changes in energy levels of a single atom. Of course this was known/proposed/assumed from quantum mechanics at the get go. Indeed Heisenberg was thinking of this very problem when he formulated his matrix version of QM in 1924. It is known by the ( much misunderstood ) phrase 'quantum jump'. It explains the bulk behaviour of large groups of atoms as demonstrated with spectroscopy. But no one had isolated a single atom ( see Penning Trap ) and found it's 'flickering' luminescence to follow a characteristic exponential decay. This is not an amazing finding or anything, but demonstrates the ongoing verification of theories that continues unabated. You don't get a headline unless you apparently make/break a paradigm these days. This is why quantification of physical theories via the precision of mathematics and good experimental technique is so important. Anyway you keep putting a Barium ion in a particular state and time it's decay to a lower energy level ( very clever technique omitted here ). Do that many, many  times. Plot the curve and get a decaying exponential. Epic. Nature does really work that way. If only Werner had lived another ten years he could have seen this  .... :-)

Cheers, Mike.

( edit ) A decaying exponential is mathematical code for 'constant chance of decay per given time interval' and especially 'future chance of decay is independent of history'. It is the key signature of true randomness and that's what annoys so many of us about QM.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

AgentB
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Mike Hewson wrote:The

Mike Hewson wrote:

The appearance needs to be considered in the presence of the context within which the supernova went off ie. why does the nebula overall look like a splattered egg. Here's a short list that comes to mind :

...

- instability in the wavefront propagation that causes irregular boundaries. 

Supernova remnants have big ears...

Mentions Vela ands CasA, two of our GW candidates, as well as the Crab Nebula (only one ear).

capnrob97
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Wow, on those scales I

Wow, on those scales I thought it would take years to even begin to see a change.

Cool, thanks for posting it.

AgentB
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https://www.nasa.gov/image-fe

https://www.nasa.gov/image-feature/new-view-of-the-crab-nebula

and the youtube version full screen at high resolution for best effect.

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