# Stellar population synthesis model parameter for galaxies in DP0

**URL:** <https://www.rubin.community/t/stellar-population-synthesis-model-parameter-for-galaxies-in-dp0/5707>\
**Category:** Support\
**Tags:** dp0\
**Created:** [July 22, 2021, 3:31pm UTC](https://www.rubin.community/t/stellar-population-synthesis-model-parameter-for-galaxies-in-dp0/5707 "2021-07-22T15:31:12Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![IlsangYoon](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/ilsangyoon/32/1658_2.png) [@IlsangYoon](https://www.rubin.community/u/IlsangYoon)\
**Post date:** [July 22, 2021, 3:31pm UTC](https://www.rubin.community/t/stellar-population-synthesis-model-parameter-for-galaxies-in-dp0/5707/1 "2021-07-22T15:31:13Z")

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Hello,  
Can I access the stellar population synthesis model parameters used to create galaxies in DP0, for each individual galaxy?

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**Author:** ![MelissaGraham](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/melissagraham/32/2549_2.png) [@MelissaGraham](https://www.rubin.community/u/MelissaGraham)\
**Post date:** [July 23, 2021, 4:51pm UTC](https://www.rubin.community/t/stellar-population-synthesis-model-parameter-for-galaxies-in-dp0/5707/2 "2021-07-23T16:51:55Z")

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Hi @IlsangYoon, thanks for your question. The short answer is “no, you can’t access the stellar population synthesis model parameters used to create the galaxies via the Rubin Science Platform as a DP0 delegate”. That kind of information is not part of the data sets being served for DP0.1 via the RSP.

But, the DP0 data set is a subset of the DESC’s DC2 data set, and the DESC have made a public release of a limited set of DC2 data products. I’m not sure that what you need is included in the public release but it’s the place to check. Maybe report back in this thread if this was useful?

> [@Public release of selected data products from DESC's DC2](http://www.rubin.community/t/public-release-of-selected-data-products-from-descs-dc2/4627):
>
> On behalf of the LSST Dark Energy Science Collaboration we are happy to announce the world-wide public release v1 of a limited set of data products from the Second Data Challenge (DC2), carried out by us recently. DC2 is a simulated sky survey, covering 300 square degrees in six optical passbands following the first five years of a reference LSST observing cadence. Details about the data can be found in the DESC paper “The LSST DESC DC2 Simulated Sky Survey” ([https://arxiv.org/abs/2010.05926](https://arxiv.org/abs/2010.05926), to…

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**Author:** ![IlsangYoon](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/ilsangyoon/32/1658_2.png) [@IlsangYoon](https://www.rubin.community/u/IlsangYoon)\
**Post date:** [July 26, 2021, 2:06pm UTC](https://www.rubin.community/t/stellar-population-synthesis-model-parameter-for-galaxies-in-dp0/5707/3 "2021-07-26T14:06:13Z")

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Thanks, @MelissaGraham I have contacted the LSST DESC data portal and asked the question. I will post it here if I hear something useful.

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**Author:** ![IlsangYoon](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/ilsangyoon/32/1658_2.png) [@IlsangYoon](https://www.rubin.community/u/IlsangYoon)\
**Post date:** [October 8, 2021, 2:53am UTC](https://www.rubin.community/t/stellar-population-synthesis-model-parameter-for-galaxies-in-dp0/5707/4 "2021-10-08T02:53:02Z")

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Hi @MelissaGraham

Very recently I started working on this and checked whether I can actually find the matched information from CosmoDC2 catalog. I selected few objects from the truth-match catalog in the Rubin science platform and used their `cosmodc2_hp` and `cosmodc2_id` to find out the object in the CosmoDC2 catalog (I only used subset of the catalog with HEALPix id) and I see the following keys and values are available. So, I think I can get the truth input parameters for each galaxy. I will need to read the CosmoDC2 paper to understand how these parameters are defined and used to create mock images. Thanks for your help.

\<KeysViewHDF5 [‘LSST\_filters’, ‘SDSS\_filters’, ‘SEDs’, ‘baseDC2’, ‘blackHoleAccretionRate’, ‘blackHoleEddingtonRatio’, ‘blackHoleMass’, ‘convergence’, ‘dec’, ‘dec\_true’, ‘diskAbundancesStellarMetals’, ‘diskMassStellar’, ‘diskStarFormationRate’, ‘diskVelocity’, ‘emissionLines’, ‘galaxyID’, ‘hostHaloMass’, ‘hostHaloTag’, ‘infallIndex’, ‘isCentral’, ‘lightcone\_replication’, ‘lightcone\_rotation’, ‘magnification’, ‘matchUp’, ‘morphology’, ‘otherLuminosities’, ‘peculiarVelocity’, ‘ra’, ‘ra\_true’, ‘redshift’, ‘redshiftHubble’, ‘shear1’, ‘shear2’, ‘spheroidAbundancesStellarMetals’, ‘spheroidMassStellar’, ‘spheroidStarFormationRate’, ‘spheroidVelocity’, ‘spinSpin’, ‘step’, ‘totalAbundancesStellarMetals’, ‘totalMassStellar’, ‘totalStarFormationRate’, ‘totalVelocity’, ‘uniqueHaloID’, ‘vx’, ‘vy’, ‘vz’, ‘x’, ‘y’, ‘z’]\>

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**Author:** ![MelissaGraham](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/melissagraham/32/2549_2.png) [@MelissaGraham](https://www.rubin.community/u/MelissaGraham)\
**Post date:** [October 8, 2021, 1:59pm UTC](https://www.rubin.community/t/stellar-population-synthesis-model-parameter-for-galaxies-in-dp0/5707/5 "2021-10-08T13:59:55Z")

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This is great to hear, @IlsangYoon, thanks for following up!

Your investigations on this might also be really useful to other delegates, I think at least a few others are interested in using the extended DC2 truth catalogs (beyond what is in the DP0 truth\_match catalog).

Also if you (or any other delegate reading this!) are interested to share your work in progress here on Community, or to present during a [Delegate Assembly](https://dp0-1.lsst.io/dp0-delegate-resources/index.html#assemblies-schedule) in Nov or Dec, and/or to contribute a demo Notebook to the shared GitHub repository for DP0 delegates, that would be great.

> **[GitHub - rubin-dp0/delegate-contributions-dp01](https://github.com/rubin-dp0/delegate-contributions-dp01)**
>
> Contribute to rubin-dp0/delegate-contributions-dp01 development by creating an account on GitHub.