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igrins / plp

IGRINS pipeline package v3
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Difference in Continuum Shape of New and Old PIpeline #26

Closed ericasaw closed 5 months ago

ericasaw commented 7 months ago

Here is an example of what the continuum looks like in the new pipeline for a .spec_a0v.fits file

bad_cont

This is what the continuum looks like in the old pipeline old_pipe

We found that the new version of the pipeline is flattening the Vega spectrum (but we are unsure why this was implemented). Kyle just pushed a fix for this to the reimplement_cr_reject branch that removes the flattening.

This is what the continuum looks like for this branch of the pipeline with this fix new_pipe

Additionally Kyle brought up the slight increase in the flux in the new pipeline (Issue #25; < 2%). We posited that as long as the A0 and the target were reduced with the same pipeline this flux difference wouldn't matter in the spec_a0v.fits files since the ratio between the target and standard would stay the same. Just want to note that things work out like we expected. Here is a single order in the old pipeline, blue, and the new pipeline (non-flattened Vega), orange, and we can see the flux doesnt have any consistent offset which is what we had hoped for good_norm

I'm basically raising this issue to document the issue occurring in the new pipeline and to ask @leejjoon if he would be upset if we turned the Vega flattening off in the next release.

kfkaplan commented 7 months ago

The bottom plot also nicely shows how the new flexure correction is leading to better telluric correction.

kfkaplan commented 5 months ago

We reimplemented how v2.2.0 handles the synthetic Vega spectrum in v3.0. @ericasaw let me know if you want to reopen this issue, otherwise I'm closing it.