-
Notifications
You must be signed in to change notification settings - Fork 2
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Efficiency of the Spectrograph #23
Comments
Hi Maddalena, |
Oh gosh! Thanks for sending the correct Pyechelle Github site.
That’s a great news about the new module that deals with the input spectra units :)
Sorry, I was not enough precise in the raised issue, I already used the spectral flux as input (ph/s/angstrom) and the wavelengths expressed also in angstrom… maybe I have to express the spectral flux in ph/s/nm, with the nm as mandatory units?
You can download a CSV that I use here:
https://filesender.switch.ch/filesender2/?s=download&token=cccb72ac-eb13-4744-afbe-0aa5a68e3909
It’s very faint target because it’s the reflected spectrum of an exoplanet + star’s halo multiplied by all the efficiencies of all the instruments, so in Pyechelle the efficiency should be set to 1. The wavelengths are in angstrom and the spectral_flux is in ph/s/angstrom. I took an exposure of one hour and then divided the extracted 1D flux by 3600 to see if it was similar to the input one (re-expressed in in ph/s), but so far it’s always different. I also tried to play with the wavelength units, but maybe not enough eheh.
Thank you very much for your availability.
Have a nice weekend,
Cordially,
Maddalena
… On 15 Mar 2024, at 19:57, Stuermer ***@***.***> wrote:
Hi Maddalena,
thanks for your report (next time though, please do it on PyEchelle repo <https://gitlab.com/Stuermer/pyechelle> :-) ).
Can you send me your CSV file ? I'm almost done rewriting the whole python module that deals with input spectra - my guess is that your issue has to do with the fact that you specify ph/s, while PyEchelle normally expects ph/s/nm (a spectral flux). I can try my new code and see how it deals with ph/s.
Best,
Julian
—
Reply to this email directly, view it on GitHub <#23 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A2XK6OPOWFAXV6LQDI7XQ4TYYNACBAVCNFSM6AAAAABEXYVWQCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDAMBQGI3TCNZRHA>.
You are receiving this because you authored the thread.
|
Hello Julien,
I have a little doubt about the efficiency that Pyechelle automatically applies on the spectrum.
In my simulations, I did not set any specific efficiency while running the simulator and I use an input source in photon/s (CSV file). I thought that the efficiency was then automatically set to 1.
However, once I extract the 1D spectrum I do not obtain something of the same order of magnitude as my input: let's say my input spectrum has an average of about 1000 photons/s, I would expect about the same average in the extracted 1D spectrum. But unfortunately I get systematically an average 40-50 times smaller than the input.
I was wondering if an efficiency is automatically computed using the affine matrices, or using the model of the CCD.
I tried the command 'sim.set_no_efficiency()' to avoid any extra efficiency, but it gives error (maybe I am calling it in a wrong way) .
Thank you very much in advance,
Cordially,
Maddalena
The text was updated successfully, but these errors were encountered: