Nebulae the black hole and Neutron star relationship

[xarcane]

Hi Guys

tpopic for tonight.

As we know when a star goes supernova If the remaining mass of the star is about 1.4 times that of our Sun, the core is unable to support itself and it will collapse further to become a neutron star.

If the remaining mass of the star is more than about 3 times that of the Sun, it will collapse so completely that it will literally disappear from the universe. What is left behind is an intense region of gravity called a black hole.

My question is does that mean inside every existing 5 types of nebulae we can find black holes and/or Neutron stars (even though some nebulae were created fromt he big bang)?

[xarcane]

I guess another question is do all supernovae create Nebulae?

[JulianO]

Nebulae already exist as vast gas clouds. They are enriched in heavier elements by supernovae, but the gas is already there. I seem to recall that about 9/10ths of the galaxy is gas and dust, and 1/10th stars, although it depends on the type of galaxy. Our Milky way still has a lot of gas, so can still form lots of stars, other galaxies are less gas rich so are often considered "red and dead" - meaning no new hot blue stars, so no new star formation.

[symesie04]

Interesting thought. Well stars like our sun still produce planetary nebula and leave white dwarfs when they die they just nova and not supernova. However and im quite prepared to be corrected here, given the long life span of and fairly recent birth of population 1 stars like our sun I dont think we currently see any planetary nebula from the death of these star types. I would assume that yes the supernova and even hypernova of the population II and massive population III stars would produce always produce either BH or Neutron stars. However given the short lifespan of of these stars (especially POP III) and the fact they were born relatively early in the universes history it would seem that there can be no guarantee that any resulting neutron/bh and planetary nebula would still hold a corresponding position. Time i would imagine could/would result in drift of the core and nebula. Given the timescale involved it must get quite difficult seprating planetary nebula from that that was created during the early creation process. Analysis of the elements is probably the only way to tell the difference I would of thought. To sum up yes I would imagine Hypernovae and Supernovae would always result in Neutron stars and Black holes but due to the time elapsed since the event it is not a certainty that these still lie at the centre of the resulting planetary nebula.

[acey]

Most nebulae aren't formed by supernovae - among the nebulae that we can readily see with amateur telescopes only 2 are supernova remnants, these being the Crab Nebula and Cygnus Loop (which includes the Veil nebula). The star that formed the Crab Nebula became a pulsar, I don't know if the originator of the Cygnus Loop has been found but this 1998 paper reported a compact X-ray source:

http://articles.adsabs.harvard.edu//full/1998PASJ...50..475M/0000475.000.html

Given that most nebulae aren't due to supernovae, and most supernovae don't result in black holes, I don't see any reason to make an association between black holes and nebulae.

[xarcane]

ok great answers, so as i understand it supernovae do not always create nebulae (but in some small cases they can), it is more of a fact that the supernovae or hypernovae add substance to the gas clouds which in turn help to form new stars, planets etc.

i must of got my facts wrong then. i used to think (until i read your responses) that nebulae were a result of supernovae and therefore if a BH or Nuetron may have some connection or co-existance with them.

thanks guys

[symesie04]

No its my understanding that supernovae would always result in a nebula remnant (not planetary as i suggested in earlier post). There are many neutron stars known to astronomy but most no longer have the nebula of their creation surrounding them. Nebula created by the death of stars (planetary or supernova) are relativley short lived. The nebula will then disperse adding its heavier elements to the background of original occuring nebula. This is why the stars being formed today are very different in the chemical makeup from the early population III stars. The first stars (confusingly population III) would of been very pure, almost totally hydrogen. Todays population I stars are more impure with traces of many heavier elements created in the supernova deaths of Pop II & III stars. The early stars were also massive due to the abundance of nebulous material available to their creation. Massive stars are short lived, created early in the development of the universe they died a long time ago. So yes most of the early stars would almost of certainly resulted in both neutron stars/BH's and nebula but the long lapse in time has resulted in the remnants being no longer associated with each other. Most of the supernovae that occur today are type 1a supernovae which are created in a process that is different to that of collapsing giant stars. I think this is correct but im always open to correction. Hope this helps.

http://en.wikipedia.org/wiki/Supernova

http://en.wikipedia.org/wiki/Nebula

[JulianO]

The early stars were also massive due to the abundance of nebulous material available to their creation. Massive stars are short lived, created early in the development of the universe they died a long time ago. So yes most of the early stars would almost of certainly resulted in both neutron stars/BH's and nebula but the long lapse in time has resulted in the remnants being no longer associated with each other.

I have to say it's still an open question how big Pop-III stars were, and how long they lived. There are complicated relationships between Eddington limits, the rate of fusion (big star with lots of C burn MUCH faster so pop III burn slower with slower winds thus affecting Eddington limits) accretion rates, and obviously the small fact we can't see any of them!

Most of the supernovae that occur today are type 1a supernovae which are created in a process that is different to that of collapsing giant stars. I think this is correct but im always open to correction. Hope this helps.

I think there are a fair smattering of all sort of supernova. Type 1a need special conditions to occur (a close binary system that had asymmetric stars) Type II and Type 1b/c are still pretty common, there was a close by type IIp this year in M95. Astronomers love type 1a though as they can be used as standard candles.

[symesie04]

I have to say it's still an open question how big Pop-III stars were, and how long they lived. There are complicated relationships between Eddington limits, the rate of fusion (big star with lots of C burn MUCH faster so pop III burn slower with slower winds thus affecting Eddington limits) accretion rates, and obviously the small fact we can't see any of them!

Isnt the fact that we cant see them and the fact that there are/have been to distinct population of stars (seemingly since) that would require the death of Population III stars to produce their less pure chemical makeup be evidence enough of the short life span of Population III stars?

I think there are a fair smattering of all sort of supernova. Type 1a need special conditions to occur (a close binary system that had asymmetric stars) Type II and Type 1b/c are still pretty common, there was a close by type IIp this year in M95. Astronomers love type 1a though as they can be used as standard candles.

Thank you Julian you are correct as usual, maybe i should make a point of reading the links i post a little more closely before making sweeping comments.