What are the compositions of planetary nebula?

[dougettinger]

Do any easily assessible studies or surveys exist that list the compositions (ions, elements or molecules) of typical planetary nebulae and/or supernova remnants (both older and more recent) at various distances from the progenitor star ?

[dougettinger]

I researched the Cat's Eye Nebula in Wikipedia and dug deeper into the references. I could not decipher from the scientific jargon whether there were more elements/molecules of anyone or more types at different distances from the progenitor star.
Perhaps there is a closer nebula than 3000 ly for the Cat's Eye Nebula where this was achieved.

[Ann]

I believe (but I may be totally wrong) that the closest planetary nebula to us is the Helix Nebula, or NGC 7293. According to Wikipedia, the distance to The Helix Nebula is about 700 light-years.

Ann

[dougettinger]

Thanks, Ann. I will research the Helix Nebula. Would you know the closest Supernova Remnant ? I am also searching for any peculiar distribution of elements in SN remnants.

[Ann]

This is what http://wiki.answers.com/Q/Where_is_the_ ... a_to_earth has to say about it:

The closest supernova, or more correctly supernova remnant, is the Vela supernova remnant [See Link] in the constellation Vela. The "guest" star exploded about 11 - 12,000 years ago and is located around 800 light years from Earth.

Click to view full size image

This is Robert Gendler's picture of the Vela supernova remnant. Pretty, isn't it?

Ann

[dougettinger]

I reviewed the Helix Nebula. Astronomers are focused on the knots and assymetry of the rings - only using spectral lines that are most easily imaged to obtain kinematic models. I need studies that possibly include lower ionization energies which would be found on the outer regions of planetary nebula. I will checkout Vela.

[Nereid]

I reviewed the Helix Nebula. Astronomers are focused on the knots and assymetry of the rings - only using spectral lines that are most easily imaged to obtain kinematic models. I need studies that possibly include lower ionization energies which would be found on the outer regions of planetary nebula. I will checkout Vela.

Do you know about the SAO/NASA ADS (Smithsonian Astrophysical Observatory/NASA Astrophysics Data Service)?

It is a very powerful resource, and with it you should be able to find lots of papers on this topic.

May I ask how familiar you are with the standard astrophysics of these sorts of objects?

[dougettinger]

Hello Nereid,

I will investigate SAO/NASA ADS. Thanks for the tip.

I am strictly an amateur astrophysicist. My interest in these objects is an investigation of how they expel matter over the period when they are creating various shells of metals in their cores. I have suspicions that their is a trend of what metals are expelled over time. The expulsion resulting from the core collapse after an iron core is created is of very special interest to me.

[Nereid]

Hello Nereid,

I will investigate SAO/NASA ADS. Thanks for the tip.

You're most welcome.

I am strictly an amateur astrophysicist. My interest in these objects is an investigation of how they expel matter over the period when they are creating various shells of metals in their cores. I have suspicions that their is a trend of what metals are expelled over time. The expulsion resulting from the core collapse after an iron core is created is of very special interest to me.

How familiar would you say you are with the standard methods of deriving estimates of (relative) element abundances of an emission nebula (or part of one) from its spectrum?

My guess is that you'd need to be at least aware of the limitations of these in order to be able to interpret the data you'll likely find in the various papers published on the topic!

[dougettinger]

When I read the more serious and detailed reports, much of the jargon is confusing. There may be a good textbook that could clarify some of my confusion if the jargon is really standardized.

Some of the limitations as I understand them are: the alignment of the structure w.r.t. to the earth's observation platform (does a survey exist that compares the number of spherical with cylindrical outbursts?); the amount of width of view that is being analyzed (I desired to see data from numerous radial distances and numerous angular degrees surrounding the center); the temperatures at various radial distances that produce the various ionization levels (do temperature gradient studies exist from the center to certain identified boundaries); the difficulty of measuring the shock wave velocities and time of its origin (I would like to know the velocity of the identified shock wave boundaries and when each originated.), etc.

Nereid, do you know of such specific reports that may help me with the listed limitations ? Many reports drift "all over creation" and fail to benefit me. Thanks for coming to the forefront to answer some of my curious queries.

[Nereid]

When I read the more serious and detailed reports, much of the jargon is confusing. There may be a good textbook that could clarify some of my confusion if the jargon is really standardized.

Some of the limitations as I understand them are: the alignment of the structure w.r.t. to the earth's observation platform (does a survey exist that compares the number of spherical with cylindrical outbursts?); the amount of width of view that is being analyzed (I desired to see data from numerous radial distances and numerous angular degrees surrounding the center); the temperatures at various radial distances that produce the various ionization levels (do temperature gradient studies exist from the center to certain identified boundaries); the difficulty of measuring the shock wave velocities and time of its origin (I would like to know the velocity of the identified shock wave boundaries and when each originated.), etc.

Nereid, do you know of such specific reports that may help me with the listed limitations ? Many reports drift "all over creation" and fail to benefit me. Thanks for coming to the forefront to answer some of my curious queries.

It's not a field I am particularly familiar with, so I don't really have any specific answers for you, sorry.

My best advice would be for you to ask yourself how interested you are in this topic.

If it is a consuming passion, then you're probably best served by committing many a month of your time to coming up to speed with the relevant, textbook astrophysics (and for that you need to be quite comfortable with a fair bit of algebra and calculus, as well as physics). Otherwise, why not take the time to work out a series of clear, pertinent questions? If you don't get answers here, then why not try PhysicsForums?