Dear Prof.Nelson:
I am analyzing TNG50-1 and would like to trace the origin of the gas within galaxies. According to Supplementary Data A, the file tr_all_groups_99_subhalo_id.hdf5 seems to be suitable for this purpose. However, I noticed that for TNG50-1, the JupyterLab interface on the website only provides the meta and parent_indexType files. Does this mean that, for TNG50-1, it is not possible to identify the origin of a galaxy’s gas ( for example, quantify the fraction contributed by fresh accretion or gas that has participated in the baryon cycle? )
In addition, I noticed that some tracer particles initially have type 4, but later may appear as type 0. Does this mean that the star has released winds at that stage? However, wind particles are also of type 4, so how should I interpret this transition from type 4 to type 0?
Thank you for your reply, this will be extremely helpful to me.
Dylan Nelson
17 Nov '25
Different "tracer tracks" files are available for different simulations, they are not all computed.
I have started tr_all_groups_99_subhalo_id.hdf5 for TNG50-1, you will find it now in the directory. (It is not yet done, but will be done in a few days).
Dear Prof. Nelson:
I am greatly appreciated for your help. The release of the subhalo_id data has been tremendously helpful for my work. I would cite the two papers you mentioned in my subsequent research.
Best regards!
怡远 张
16 Dec '25
Dear Prof. Nelson:
I have carefully read three representative papers —Nelson et al. (2020) and Ramesh et al. (2023, 2025)— which gives me several ideas regarding cold clouds. I would like to follow the analyses presented in these works first. However, as the full TNG50 dataset is too large to be stored locally and the web-based Jupyter is limited to 10 GB of memory, having additional post-processed tracer data would be extremely helpful.
Therefore I was wondering whether it would be convenient for you to further release the TNG50-1 tracer datasets tr_all_groups_99_temp.hdf5, pos.hdf5, and vel.hdf5. I would be extremely grateful if this could be made available. Thank you for your reply!
Best regards!
Dear Prof.Nelson:
I am analyzing TNG50-1 and would like to trace the origin of the gas within galaxies. According to Supplementary Data A, the file tr_all_groups_99_subhalo_id.hdf5 seems to be suitable for this purpose. However, I noticed that for TNG50-1, the JupyterLab interface on the website only provides the meta and parent_indexType files. Does this mean that, for TNG50-1, it is not possible to identify the origin of a galaxy’s gas ( for example, quantify the fraction contributed by fresh accretion or gas that has participated in the baryon cycle? )
In addition, I noticed that some tracer particles initially have type 4, but later may appear as type 0. Does this mean that the star has released winds at that stage? However, wind particles are also of type 4, so how should I interpret this transition from type 4 to type 0?
Thank you for your reply, this will be extremely helpful to me.
Different "tracer tracks" files are available for different simulations, they are not all computed.
I have started
tr_all_groups_99_subhalo_id.hdf5for TNG50-1, you will find it now in the directory. (It is not yet done, but will be done in a few days).I hope it will be useful for your analysis.
In terms of changing particle types, see Sec 3.1.3 of Nelson+15b or Sec 2 of Nelson+15a.
Dear Prof. Nelson:
I am greatly appreciated for your help. The release of the subhalo_id data has been tremendously helpful for my work. I would cite the two papers you mentioned in my subsequent research.
Best regards!
Dear Prof. Nelson:
I have carefully read three representative papers —Nelson et al. (2020) and Ramesh et al. (2023, 2025)— which gives me several ideas regarding cold clouds. I would like to follow the analyses presented in these works first. However, as the full TNG50 dataset is too large to be stored locally and the web-based Jupyter is limited to 10 GB of memory, having additional post-processed tracer data would be extremely helpful.
Therefore I was wondering whether it would be convenient for you to further release the TNG50-1 tracer datasets tr_all_groups_99_temp.hdf5, pos.hdf5, and vel.hdf5. I would be extremely grateful if this could be made available. Thank you for your reply!
Best regards!