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Gasman

Argon lines ID please?

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Hi guys

I`m making an adaptor to align my Argon/Neon (Relco) lamp bang on line with the Alpy slit. First try at a 60sec exposure looks very promising to cover  quite a wide portion of the visible spectrum. This is just a 60sec raw , no hot pixels removed or anything just to see what lines are available.

post-15973-0-01256200-1395165475_thumb.j

My problem is identifying the Argon lines for calibration. I have the Neon mapped out ok and can id all those but info on the Argon lines is a bit sparce and I`m wondering if anyone could put a wavelength to a few of those lines towards the blue end if poss please?

post-15973-0-06561000-1395165143_thumb.j

Thanks

Steve

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Steve,

Why not capture A class & Argon lamp spectra at the same time. A variety of exposure time might be needed to get the right balance.  The Balmer lines will give you some pointers for the Argon lines.

Are you running Neon + Argon lamps together? If so, you could reduce the intensity of the Neon by adding a few mega ohms more resistance?

cheers

John

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John,

The relco starter lamp emits both the Argon and Neon - the neon being more pronounced.

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Thanks Ken some useful data on Christians site, still trying to source those ruddy Filly bulbs here in the UK!.

John- As Ken says the Relco bulb has both Neon and Argon which if I can get the exposure right  (maybe 90-120secs?) to pull out the Argon lines and not over do the Neon ones and ID a couple of those fainter Argon lines it should be a nice `one light` solution

Steve

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I was about to say - use one exposure of the neon and another for the Argon ( I use a 8sec for neon and a 20 sec for the argon) but I think you're using the ALPY with full spectral coverage...could still be done if the instrument is "stable"

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Cheers Ken. I think if I just use the Neon lines initially (as I can id those) to get an approximate value for the Argon lines and match them up with Christian`s Table 106 I should be able to id the lines for future use!

Steve

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Thanks Chris I'll try those later!

Cheers

Steve

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Richard Walker has identified most of the useable lines in the Relco spectrum here

http://www.ursusmajor.ch/downloads/sques-relco-sc480-calibration-lines-2.0.pdf

but take care as this was taken an higher resolution and not all these are cleanly resolved at the ALPY 600 resolution.

Here is an example of  the ones ISIS used when calibrating using the ALPY calibration lamp which has the same spectral content as the relco starter lamp.

It is taken from the printout of an actual calibration. The first  set was used to do the calibration and then a second set to verify the calibration.

Primary wavelength fit deviation
point #1  Lambda = 3770.630  px = 222.807  dx = -0.045
point #2  Lambda = 3797.300  px = 226.647  dx = 0.105
point #3  Lambda = 3835.390  px = 232.122  dx = -0.054
point #4  Lambda = 3889.050  px = 239.818  dx = -0.009
point #5  Lambda = 3970.080  px = 251.404  dx = 0.029
point #6  Lambda = 4101.750  px = 270.151  dx = -0.034
point #7  Lambda = 4340.480  px = 303.947  dx = -0.011
point #8  Lambda = 4861.340  px = 377.250  dx = 0.027
point #9  Lambda = 6562.850  px = 621.117  dx = -0.048
point #10  Lambda = 6869.000  px = 666.565  dx = 0.046
point #11  Lambda = 7605.000  px = 778.030  dx = -0.006
--------------------------------------------------------------------------
Wavelength fit deviation
point #1  x = 146.546  lambda = 3946.141  dlambda = -0.041
point #2  x = 176.493  lambda = 4158.643  dlambda = -0.053
point #3  x = 226.050  lambda = 4511.126  dlambda = -0.396
point #4  x = 230.699  lambda = 4544.209  dlambda = 0.841
point #5  x = 246.694  lambda = 4658.018  dlambda = -0.118
point #6  x = 261.699  lambda = 4764.730  dlambda = 0.140
point #7  x = 289.972  lambda = 4965.564  dlambda = -0.484
point #8  x = 351.490  lambda = 5400.628  dlambda = -0.068
point #9  x = 415.985  lambda = 5852.288  dlambda = 0.202
point #10  x = 475.929  lambda = 6266.374  dlambda = 0.116
point #11  x = 511.159  lambda = 6506.636  dlambda = -0.106
point #12  x = 607.063  lambda = 7147.152  dlambda = -0.112
point #13  x = 643.364  lambda = 7383.902  dlambda = 0.078
--------------------------------------------------------------------------
Coefficient a4 : 7.308068E-10
Coefficient a3 : -2.277032E-06
Coefficient a2 : 1.310744E-03
Coefficient a1 : 6.83895
Coefficient a0 : 2922.597
--------------------------------------------------------------------------
RMS : 0.391258

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Here is an example of  the ones ISIS used when calibrating using the ALPY calibration lamp which has the same spectral content as the relco starter lamp.

It is taken from the printout of an actual calibration. The first  set was used to do the calibration and then a second set to verify the calibration.

note that the wavelengths listed in the first set are the actual wavelengths of the lines. the wavelengths in the second verification set are  the wavelengths of the lines as they appear using the calibration so you need to add the error dlambda to them to get the actual wavelength. 

note that If you use ISIS to calibrate your relco lamp spectrum, just telling it the position of the one bright Ne line at 5852A, it will  produce a fully calibrated spectrum of your lamp automatically.  ISIS takes some time to get used to (I am not there fully yet) but it is a staggeringly clever bit of software

Cheers

Robin

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I`m glad you said that Robin as after four evenings trying ISIS I was on the verge of putting it aside for another day but I`ll persevere with it now!.

I thought I had it last night using an Argon/Neon spectrum to calibrate a shot I did of beta UMa the other night. Did the processing of beta UMa fine but when I then redid it ticking the `spectral calibration` box I ended up with this screen ???

post-15973-0-92699800-1395257334_thumb.p

Not the most helpful of error screens and obviously some variable is not quite right yet!.

What made me want to try ISIS was the thought of being able to take a nice crisp spectrum of the Relco lamp, stick it in ISIS,id the 5852 angstrom Neon line and voila the calibration for  the night !!! :smiley:

regards

Steve

Edited by Gasman

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Is there an electronic resource for providing a catalogue of lines?

Like astrometry.net, where you provide parameters for the resolution and it provides a catalogue of peaks for the specified range?

A self hosted version would be fine (not just a web page you plug details in).

Edited by NickK

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I don't think so Nick. I have just been comparing the Neon profile I produce with the profile on Christian's web site to I'd the emission lines. If I'm able to crack it with ISIS it should be a straightforward job to calibrate the lamp for the night !

Steve

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