Opened 8 years ago

Closed 7 years ago

Last modified 7 years ago

#137 closed enhancement (fixed)

continuum energy mesh should become finer across the radio, and extend to longer wavelength

Reported by: Gary J. Ferland Owned by: nobody
Priority: good to do Milestone: database infrastructure
Component: infrastructure Version: trunk
Keywords: Cc:

Description (last modified by Gary J. Ferland)

in the discussion following Ryan's plot of the lamda emission spectrum, Peter pointed out that many of the lamda lines fall in regions of the continuum mesh with very low resolution. Ryan pointed out that some lines fall below the longest wavelength of 10 meters. Peter pointed out that some telescopes hope to observe down to 30 meters.

should continuum resolution be increased, perhaps to be the same down to the low-energy limit of the code?

should the low-energy limit be extended to a longer wavelength, so long as to include all conceivable observations?

I think that the answer to both is yes, if we are going to do this right.

Change History (5)

comment:1 Changed 8 years ago by Gary J. Ferland

Peter to my "we are safe until they put radio telescopes on the moon."

Not quite...

http://www.lofar.org/

They go down to 10 MHz, i.e. 30 m.

could it be that wikipedia was not precisely correct??? I wonder how often they can get to that long a wavelength?

In what sense? They also state that LOFAR goes to 30m. I have no idea how often they can reach that.

it would be a fair amount of work to extend the array due to numerous lookup tables. The grain refractive index data and the table continua are the two biggest examples. Linear extrapolation was what I did last time the array was extended. it is probably a day's work to do this. If you do i would go beyond what they hope to observe - perhaps go to 100m.

The rfi files should be automatic, the same goes for the stellar atmospheres. Not sure about other tables. If this is a lot of work, the case for extending the grid may seem fairly marginal. On the other hand, if we increase the resolution of the radio grid, all compiled opacity and stellar atmosphere files will need to be remade. It would be better to extend at the same time if we want to go that way, so that we don't have to hassle our users twice...

We should also check what the Indians are doing with their low-frequency array.

comment:2 Changed 7 years ago by Gary J. Ferland

the higher optical resolution was extended to the low-energy limit of the code in r4121. This closes the part of the discussion on the energy resolution. Nobody was interested in doing the work to extend the energy grid to longer wavelengths, in effect closing this ticket.

comment:3 Changed 7 years ago by Gary J. Ferland

Description: modified (diff)

comment:4 Changed 7 years ago by Gary J. Ferland

Resolution: fixed
Status: newclosed

comment:5 Changed 7 years ago by Gary J. Ferland

Milestone: Chianti lambda databasesdatabase infrastructure

Milestone Chianti lambda databases deleted

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