On Sat, 15 Jun 2013 16:36:23 +0100 ... Re. Usual pipeline's output are lines profiles with a firtsdt order calibration law. This is made to let other softs...
14285
Stan Gorodenski
stanlep@...
Jun 15, 2013 4:33 pm
p.s., in the past I have entered the calibration line wavelengths and pixel locations in SPSS (as statistical package with programming capabilities) and...
14286
Robin Leadbeater
niborl2000
Jun 15, 2013 4:55 pm
... Note that the default setting in RSpec though is not to output spectgrum profiles (dat files) with equal bin size. This can confuse other software eg...
14287
Carl Sawicki
carl_of_alpine
Jun 15, 2013 5:39 pm
A question to all "gadgeteers": Has anyone ever tried to make an LHires thermally stable? My idea of thermally stable is +/- 1 deg. C. The reason I am...
14288
Christian Buil
chbuil
Jun 15, 2013 5:44 pm
Spectroscopy of some special liquid (some are popular in France and anywhere)... ! See: http://www.astrosurf.com/buil/liquid_spectro/result.htm More seriously,...
14289
Christian Buil
chbuil
Jun 15, 2013 7:40 pm
Le CNES fait bien les choses, faut le dire ! Vous pouvez même voir quel est mon quotidien ici : http://smsc.cnes.fr/MICROCARB/Fr/GP_actualites.htm (là...
14290
Stan Gorodenski
stanlep@...
Jun 15, 2013 8:13 pm
Is what I am thinking of called the Lanthier shutter? Was it Ash dome that had this option? It was a transparent cover over the opening of the observatory. If...
14291
Stan Gorodenski
stanlep@...
Jun 15, 2013 8:18 pm
It looks like Gin might be the best for overall general satisfaction because of the wide wavelength range of high intensity values. Surprisingly, it is close...
14292
Christian Buil
chbuil
Jun 15, 2013 8:37 pm
About, about Gin and water, it is also my conclusion ;-) (... it is the conclusion of Alpy in fact, for the visible spectrum). In French, we have the...
14293
jacot
savardjacque...
Jun 16, 2013 2:37 am
I temaly lower my webcam whit my electronic cooler The equipment as a pelltier system on top whit fan inside and outside I just add a spacer and a fan...
14294
Bernard Heathcote
spectrasouth
Jun 16, 2013 10:44 am
Hi Benji, I agree that the dispersion of a grating is not absolutely linear, due to the cos (θ) component, but as the diffraction angle θ is small the cos...
14295
Christian Buil
chbuil
Jun 16, 2013 1:23 pm
New spectrum of SN2013df at V=14.8 (C11 + Alpy) for the 15.9/06 http://www.spectro-aras.com/forum/viewtopic.php?f=5&t=614&p=2356#p2356 Christian...
14296
BM
bmauclaire@...
Jun 16, 2013 6:22 pm
On Sun, 16 Jun 2013 20:44:46 +1000 ... Hello Bernard, For a reflective gratings, relationship between coming light angle "i" towards grating and reward light...
14297
Bernard Heathcote
spectrasouth
Jun 17, 2013 4:16 am
Hi Benji, An interesting and important discussion. I agree with your methodology but not with your results, as I believe you have made an arithmetical error in...
14298
Ken
ken4optics
Jun 17, 2013 5:25 am
Interesting stuff! When I put in a 150 l/mm grating, 100mm imaging lens, 6.45pixel camera in a Classical configuration into the SimSpec V4 spreadsheet I get...
14299
Ken Harrison
ken4optics
Jun 17, 2013 5:31 am
When you use a Littrow configuration - same grating etc dispersion @ 4000A = 8.43A/pixel dispersion @ 7000A = 8.42A/pixel Considering rounding errors, less...
14300
Bernard Heathcote
spectrasouth
Jun 17, 2013 6:01 am
Hi Ken & Ken, My calculations assume the incident beam is normal to the grating (sin[i]=0) as in the Littrow, but not for the Classical, design so that would...
14301
BM
bmauclaire@...
Jun 17, 2013 7:35 am
On Mon, 17 Jun 2013 14:16:41 +1000 "Bernard Heathcote" <spectrasouth@...> wrote: Hello Bernard, Kent, ... Bernard, you pointed out the computation...
14302
m_dubs98
Jun 17, 2013 7:51 am
Hello everybody, the original question was about the nonlinearity of a DADOS spectrograph, which is characterized by a total deviation angle of 90°, so quite...
14303
Ken Harrison
ken4optics
Jun 17, 2013 7:58 am
Martin, If you put the total angle at 90 degrees in SimSpecV4, with a 200 or 900 l/mm grating - you see than answer....... Your polynominal is required!! ... ...
14304
Robin Leadbeater
niborl2000
Jun 17, 2013 11:16 am
Hi Ken, Experiment trumps theory though. If you take a practical Littrow spectrograph eg the LHIRES III and use a linear calibration you get significant errors...
14305
Bernard Heathcote
spectrasouth
Jun 17, 2013 12:13 pm
Hi Robin, There is no doubt that Lhires spectra need a polynomial wavelength correct applied, but would you not agree that this is mainly due to the effects of...
14306
Bernard Heathcote
spectrasouth
Jun 17, 2013 12:24 pm
Hi Benji, Martin, Ken, The value of these sorts of discussions it that I think we all learn a bit more every time. For example, while I believed gratings were...
14307
BM
bmauclaire@...
Jun 17, 2013 1:25 pm
On Sat, 15 Jun 2013 17:39:42 -0000 ... Hello Carl, There is an other way to manage Lhires's lens focusing: use of a motor. See this page: ...
14308
Filipe Dias
fil_days
Jun 17, 2013 2:51 pm
Personally I like the idea of constructing things in styrofoam. You can warm it up to a desired (constant) temperature, or cool it to that temperature (more...
14309
Robin Leadbeater
niborl2000
Jun 17, 2013 4:02 pm
Hi Bernard, It could be. To be honest, I had not even realised that a theoretical Littrow should be linear until Ken pointed it out. The non linearity does...
Hi again; Does this mean that all spectrographs find linearity problems due to focal planes and various incidents lenses, plus each grating spectrograph...
14312
Bernard Heathcote
spectrasouth
Jun 18, 2013 2:51 pm
Hi Alfonso, Yes, that is basically the situation, and prism based spectrographs are a lot more non-linear that gratings. As explained in previous posts...
14313
BM
bmauclaire@...
Jun 18, 2013 3:46 pm
Hello, Ha's line has rapidly envolve in 2 seperate compenents with a start of P Cygni profil. Note the bumped continuum at 6610 A. Ha's wings have so mutch...
