Computing Star-Formation Rates and SFR Densities using Marvin solution?

[TheRealEKL]

I am currently trying to calculate the star formation rates of some galaxies using this exercise, but I am a bit confused. I was wondering if there was a solution (like there are for the other Marvin exercises) available somewhere? Would really appreciate this, thank you!!

[havok2063]

Hi @TheRealEKL I don't think we have a solution available. I'm not the original author of that exercise. Is there a particular step you are getting confused on? I can try to help.

[TheRealEKL]

Mainly steps 4-6. I am not sure how to apply the S/N cutoffs that are listed. Also, I am trying to calculate SFR's of E+A galaxies so I am interested in areas where the SFR is zero so I do not want that to get masked out. Lastly, specifically how to retrieve the flux of H-alpha and H-beta; is this flux simply the emission of H-alpha and H-beta? Or will I need to make use of the equivalent width at the continuum to retrieve the flux? Thanks!

[havok2063]

Ahh ok, I can try to point you in a few directions that might help. For steps 4-5, see the the Marvin BPT docs, for how to use this feature, apply S/N cutoffs, use the masks, etc. For steps 5-6, see the following two plotting tutorials for examples of how to use the masks on flux plots: plot H-alpha map of SF spaxels and Plot flux ratio map of SF spaxels.

Also see the Maps and Map docs for how to retrieve flux maps from the MaNGA maps. And for what the flux is, please see the "Data Analysis Pipeline" sections in the main SDSS docs:

• https://www.sdss.org/dr17/manga/manga-data/data-model/#DataAnalysisPipelineOutput
• https://www.sdss.org/dr17/manga/manga-analysis-pipeline/
• https://data.sdss.org/datamodel/files/MANGA_SPECTRO_ANALYSIS/DRPVER/DAPVER/DAPTYPE/PLATE/IFU/manga-MAPS-DAPTYPE.html