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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 ...
Firestar-Reimu's user avatar
2 votes
1 answer
165 views

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 ...
ergoldan675's user avatar
2 votes
0 answers
48 views

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 ...
ALIEN X's user avatar
  • 21
1 vote
0 answers
212 views

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 ...
Abhinna Sundar's user avatar
1 vote
1 answer
100 views

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 ...
Dhruv Nayak's user avatar
1 vote
1 answer
118 views

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 ...
Dhruv Nayak's user avatar
4 votes
1 answer
240 views

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 ($...
Tutan's user avatar
  • 73
2 votes
1 answer
290 views

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' ...
march_happy's user avatar
2 votes
1 answer
283 views

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-...
AHMED KRS's user avatar
1 vote
1 answer
165 views

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 ...
qqqqq's user avatar
  • 163
1 vote
1 answer
186 views

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 ...
Shakti's user avatar
  • 43
5 votes
2 answers
407 views

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 ...
Mass's user avatar
  • 153
1 vote
2 answers
291 views

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 ...
K F's user avatar
  • 11
1 vote
0 answers
44 views

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 ...
Rulx Narcisse's user avatar
1 vote
1 answer
386 views

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?
Rulx Narcisse's user avatar
2 votes
0 answers
347 views

How to calculate angular size in ds9?

How to calculate the approximate angular (how many degrees across?) from an image in DS9 rendering?
Rulx Narcisse's user avatar
1 vote
0 answers
521 views

Galactic coordinates input in DS9

I have uploaded a h alpha photo in SAO Image DS9, but want to locate a particular region for which I have the galactic coordinates. How to input the coordinates in DS9 to view the particular zone?
Rulx Narcisse's user avatar
1 vote
1 answer
3k views

how to get image coordinates of source points in saoimage ds9?

I loaded my fits image to saoimage ds9. Then, Analysis->Catalogs automatically brought up source locations. how can i get xy image coordinates of this source locations?
orkan's user avatar
  • 113
4 votes
1 answer
596 views

Save current state in ds9?

After fooling around with a FITS file(s) (e.g. setting scale, changing color) is it possible to save the session such that there is a file associated with all those tweaks the next time I open it up? ...
Aaron's user avatar
  • 1,518
6 votes
2 answers
523 views

Adjust axis labels in ds9

How can I adjust the axis labels in ds9? I'd like to have something like: So far I only managed to get floating points (tl h%f3): or the leading hours are missing (tl h%f1 m): Edit: I tried "tlhm....
samcarter_is_at_topanswers.xyz's user avatar