Questions tagged [ds9]
Questions about the visualization tool for FITS images and data.
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how to set a image normalization similar to the default scale for SAOImageDS9 zscale
I want to draw this picture using mmatplotlib, and I want to set the normalization to be Exactly Same as zscale (as in the below image)
for example, I can use simple_norm or general ImageNormalize
but ...
- 191
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181
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Measuring magnitudes in ds9
I'm currently working on a project which involves measuring several Cepheids to determine the distance to a galaxy. I have been using 12 images from the Hubble telescope taken over a period of about a ...
- 21
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ds9 configuration issue
I'm trying to use DS9 for X-ray image analysis. Before that I have to configure it for use, I need to click on option using web proxy.
Beside use internal web browser checkbox there should be another ...
- 21
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241
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Split Multi-Extension fits file - fits.fz format
I have CFHT/MegaCam fits.fz file on which I want to do photometry. I want to split these large fits.fz file into separate CCD detector fits and then run Source Extractor on them for photometric ...
- 111
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What parameters about galaxies can be measured using SAO DS9?
I am trying to determine and plot various parameters for galaxies on SAO DS9. RA & dec, angular size to a fair extent, and contour plotting are a few of the aspects which I could determine using ...
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119
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How is CASA different from SAO DS9?
I was told that CASA is used extensively in Radio Astronomy. However, softwares like SAO DS9 and also python (Astropy) are also used for radio astronomy data analysis. So, what makes CASA different as ...
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4
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252
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Flux density from brightness map
This is a naive question. I have a temperature map of radio emission at 1420 MHz, in Kelvin. I want to extract the flux density (in Janskys) from an extended region of this map.
Is the flux density ($...
- 73
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296
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Align multiple fits images without WCS for future aperture photometry analysis
Recently I have got a bunch of raw fits images (2048x2048 pixels) of the same sky region without WCS to process in iraf. However, those images are not well-aligned. There would be around 4~5 pixels' ...
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288
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How to convert from FELO-HEL to Km/s?
I am using DS9 to calculate the rotational velocity of a galaxy. I have 21cm cube and I used DS9 to plot this graph
I do not understand what is FELO-HEL! and I want to convert the units from FELO-...
- 35
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178
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CoRoT FITS files read error
I downloaded fits file using wget script from https://exoplanetarchive.ipac.caltech.edu/docs/datasethelp/ETSS_CoRoT.html
I am not able to view the file. I tried atsromagic and DS9 . After File->Open ...
- 163
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Loading contour file in ds9
I have an ASCII file (.con) with the coordinates of vertices of different contours. This file is obtained from Matlab. Now after every set of contour ends there needs to be a blank row in the contour ...
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414
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Excluding a rectangular region from an image in FITS
I am a complete beginner in astronomy. While learning DS9, I came up with the following question.
Say I want to exclude a boxed region from an image FITS. The corresponding parameters according to ...
- 153
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2
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292
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Determine distance from the galactic center in DS9
I have a list of coordinates of black hole/neutron star systems in decimal degrees (ie. {(266.416,-29.009), (266.418,-29.009),...} from DS9 and would like to determine the distance from SgrA* in ...
- 11
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help needed with inactivated option for wcs in SAO Image DS9
Another trouble in SAOImae DS9: with the Rotation Measure catalogue I have just downloaded: “Rotation measure image of the sky (Taylor+2009)”, even if I have set up the WCS to galactic before the ...
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What unit is used for region Surface brightness in DS9?
The value of the surface brightness is in what unit? I hope it is in Rayleighs. Is that true?