Week 3: Querying progress

What I completed last week:

  • Made a separate git repo for my GSoC related work. This will make it easier to track changes, make suggestions, etc
  • Edited the first tutorial such that:
    • The only data files left in notebook are the CCD quantum efficiency table. The other bits of data are queried/modeled with astropy.utils.download_file(), astroquery.gaia, and pwv_kpno.
    • There is now a preamble including authors, objectives, keywords, and links to different sections throughout the tutorial
  • Contacted the Spanish Virtual Observatory and asked them to add the primed SDSS filters (which are used at APO) to their filter profile service, which they have now done!
  • Explored using pwv_kpno as an atmospheric model. I was struggling with it at first, but I didn’t wait too long to raise an issue on its github page. Daniel was very helpful and responsive, and things are running smoothly now. Because pwv_kpno‘s main functionality is modeling the effects of precipitable water vapor on the atmospheric transmission, it isn’t a complete atmospheric model (it doesn’t claim to be) since it doesn’t include the opacity due to Rayleigh scattering. While this would be okay for observations in the infrared, it significantly affects our visual-band count estimates.
  • Addressing the above, I’m going to try Brett’s suggestion to use skycalc_cli and see if that makes a more complete atmospheric model. To do this, I am going to borrow the bit about querying from Cerro Paranal from skycalc, and perhaps eventully turn this into an astroquery pull request.

This week’s goals:

  • In the first tutorial, edit the bandpass retrieval to query from SVO instead of APO. Alert the github universe when it’s ready to be looked over!
  • Create a short example of Kepler (i.e. space-based) counts for HAT-P-11 and TRAPPIST-1
  • Keep investigating skycalc_cli for atmospheric transmission models
  • Begin working on Example 2: Empirical spectrum (like from SDSS/Hubble website) -> Synthetic photometryExample: Erik’s palomar spectrum + MDM Halpha observations
  • Begin working on the Astroquery pull request? (mentioned below)

Longer term goals:

  • Make 4-5 notebooks which explore different use cases in order to get an idea of how we want to implement any changes or enhancements to synphot:
    1. Model spectrum -> Synthetic photometry
      • Ground-based example: existing APO notebook
      • Space-based example: existing APO notebook + Kepler
    2. Empirical spectrum (like from SDSS/Hubble website) -> Synthetic photometry
      • Example: Erik’s palomar spectrum + MDM Halpha observations
    3. Model spectrum -> synthetic spectroscopy
      • Example: Observations of a G dwarf with [the space-based mission Brett mentioned called CHEOPS, but don’t worry about that] at R~1k vs 100k – what count rates do you get?
    4. Empirical spectrum -> synthetic spectroscopy
      • Possible example: Some HII region spectrum -> how many hours to a S/N of X
  • Implement a signal-to-noise predictor
  • Create a pull request to Astroquery to enable queries to the filter VO service for filter transmittance curves
That’s a lot of water vapor…
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