LEVEL Y

[Joan Guarro Flo]

To all :

Is there any application that is determined will raise some points on a graph, and let the software at the same height in Y? I think this would be very useful to determine the relative intensity of lines and bands in a series of observations of several nights. For example, now on the star WR140.

Many tanks, Joan.

[Robin Leadbeater]

Hi Joan,

If your spectrum is corrected for instrument response, you should find your 2 points at the right end are approximately at the same level but the 3rd point from the right is definitely higher so should not be corrected down (if you do, the flat topped line will show a slope). I suggest rectifying the spectra using the pseudo continuum points that Marchenko used here in fig 5
http://adsabs.harvard.edu/cgi-bin/nph-b ... .596.1295M

Cheers
Robin

[Joan Guarro Flo]

Hi Robin:

I totally agree with you, the third from the right point, you must cancel, it makes no sense, it is forced. The Fig. 5 is a good example.

This morning I sent the T.Moffat and T. Evergsberg this PNG (and also Paolo Berardi) indicate where the wavelengths for the same level Y. Also I have sent some results, with no example. I'm waiting for her answer.

Thank you and Merry Christmas, Friendly, Joan.

[Tim Lester]

If I understand correctly PlotSpectra's 'normalize continuum' tool should do what you want.
First deselect all points and then select small regions around the points you want to normalize to and add them one by one. You can zoom in to make this easier.
Finally adjust the 'stiffness' until the line goes through all points suitably. This can be done to many spectra at once.

Here I have done this for my last result:

I have updated PlotSpectra and added a button to the continuum tool for deselecting all points. Without this it was hard to deselect the first and last points of the data.
Update can be downloaded from: https://1drv.ms/f/s!AvXqhKI5kEGRjEhdaQ6jaj8AHx_L

Tim

[Robin Leadbeater]

I expect the campaign PI will probably prefer to have the spectra before rectification as they can then rectify all the spectra from different observers using the same procedure.

Cheers
Robin

[Joan Guarro Flo]

Thanks Tim,

Forgive me, I must learn to operate PlotSpectra's better, but I think the continuum, that would be formed by a series of straight lines that united the various puns value 1. I tried and values are fit best.

  Robin, again return to agree with you.
 
But T. Eversberg, found variations in graphics, which had previously gone unnoticed forgive, but here and now, I can not be more explicit. He should explain it.

Good New Year, Joan.

[Paolo Berardi]

Hi all! Joan, thank you for raising the issue here. The reference point at 575 nm was indeed a bit strange (too high). The new feature of PlotSpectra about continuum normalization is excellent. Anyway I also think that this delicate task should be done by astronomers with our spectra normally reduced.

Paolo