Metallicity abundances by elements

Lucas Bignone
  • 24 Aug '16


I understand from the documentation that the metallicity available in the snapshots and group catalogues refers to all metal elements (above He). Is the metallicity abundances by elements (i.e. [Fe/H]) available in any form?

Thank you very much

Dylan Nelson
  • 1
  • 8 Sep '16

Hi Lucas,

This information is not described and is not really part of the original Illustris simulation data release. The reason is that we determined that several issues/problems exist with this data (in the original Illustris simulation, not in the TNG simulations), and therefore any interpretation or scientific conclusions become very difficult to make.

If you download a full snapshot you will find this information in the GFM_Metals field. It is a {N,9} size array, for both gas and stars, where the 9 entries are: Individual abundances of nine species: H, He, C, N, O, Ne, Mg, Si, Fe. You are of course welcome to look and play with this information, but I would have to caution against its scientific use. In practice, abundance ratio analysis and other interesting things along these lines will have to wait for the next simulation to come.

Marcos Castillo BugueƱo
  • 1
  • 14 Mar

Hi Dylan,

I hope this message finds you well. I have a question regarding the issues mentioned. Do these concerns extend to the abundances of Fe and H in TNG50? Additionally, are the abundances in "GFM_metals" distinct from those obtained in Auriga?

Appreciate your assistance.

Dylan Nelson
  • 15 Mar

I have edited my above comment from 2016 to be clear that it refers only to the original Illustris simulation.

The abundance in TNG50 are fine.

The abundance in Auriga make different assumptions, and differ in detail from those in TNG, but for more information you should consult the Auriga documentation.

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