Comments on: FITS images with catalog overlays

By: Gus

Gus — Thu, 14 Apr 2011 13:49:02 +0000

it is a bit disconcerting to see mac osx aqua lumped with solaris and windows as not supported for 6.2 though. disconcerting but i can’t but believe it won’t return sometime soon.

By: Jessica

Jessica — Tue, 12 Apr 2011 15:56:15 +0000

SAO Image ds9 v 6.2 is released and works great for catalogs in pixel coordinates now!

http://hea-www.harvard.edu/RD/ds9/

By: Ken Nordsieck

Ken Nordsieck — Mon, 11 Apr 2011 20:36:06 +0000

What ever happened to DS9 version 6.2?

By: Shantanu

Shantanu — Mon, 21 Mar 2011 23:30:49 +0000

quick question: can skycat and gaia view fpacked (.fz images)?

ds9 can.

By: William Joye

William Joye — Wed, 15 Sep 2010 16:12:57 +0000

The next version of SAOImage DS9, version 6.2, supports catalogs in any coordinate system. Just select the the coordinate system from the menu button, next to the menu buttons used to select the columns of the table to be used for x/ra and y/dec.

A beta will be available shortly, with the official release scheduled for Oct 15th.

By: Tigran Khanzadyan

Tigran Khanzadyan — Fri, 19 Mar 2010 10:05:09 +0000

Re: Jessica I would say it's easy to get going just with SkyCat Tool alone. You open the Fits file as you would open with ds9 and then you overplot as many catalogues as you wish every time changing the symbols and the colours. You can in principle create a publication ready figure in a little over 10 minutes (export as EPS or print to EPS). GAIA itself adds lot's of layers of possibilities. You can overplot contours from some other image defining the values, thickness and colours. Have a look at this address: http://astro.dur.ac.uk/~pdraper/gaia/gaia.html. All the Starlink suite comes with an extensive documentation which is updated regularly. Everything works quite well under Mac and the current Starlink Support Page at JAC Hawaii has more info on many available platforms: http://starlink.jach.hawaii.edu/starlink.

By: Tanya

Tanya — Thu, 18 Mar 2010 19:57:25 +0000

While ds9 is my main viewing tool, I sometimes use skycat (http://archive.eso.org/cms/tools-documentation/skycat). I like their custom catalog overlay, but it’s a little bit hard to explain, mainly because the tabbed catalogs need to be in a certain format.

Tab Data-Servers -> Local Catalogs -> Load from file. Tab Options -> Set plot symbols. Again, if you’re already familiar with ds9 and it’s region file formats, I would probably go with that. I mainly just use this, because I started with it as an undergrad while in Germany and out of laziness never changed.

By: Jonathan Foster

Jonathan Foster — Thu, 18 Mar 2010 18:03:17 +0000

1. ds9 (or Kvis, part of Karma)
2. There are several python interfaces to ds9. Currently I’m using Jae-Joon Lee’s pysao (http://code.google.com/p/python-sao/). With this, you can pretty easily overlay any catalog that you can get into python onto a ds9 window (and still play around with all the ds9 tools). It’s a python wrapper to the XPA, so it’s helpful to know both python and the XPA interface for ds9.
3. I don’t think so, directly. Region files are the best way I know of to display the position of lots of xy coords- they are nicely scriptable through point #2.

By: Eduardo Balbinot

Eduardo Balbinot — Thu, 18 Mar 2010 16:59:53 +0000

1. ds9
2. I just use IRAF task like mscgetcatalog + msctvmark. Or like Ivan said, for new catalogues I use sky2xy (our vice-versa xy2sky) from wcstools.

Concerning question #3. My solution does not use ds9 as the ‘interactive display’. I use APLpy together with the connect() function provided by matplotlib. It is really simple to just point and click to gather information or deleting a source. I have some examples on my blog about how to interact with matplotlib (http://astro-stuff.blogspot.com/2010/01/mais-python.html) sorry but it is in portuguese, just copy and paste the code and see what it does.

By: Jessica

Jessica — Thu, 18 Mar 2010 15:44:58 +0000

Thanks for all the great comments… keep them coming. To clarify Question #3 a little more, I am fully aware of the region functionality and that is what I am currently using. However, the catalog tool is far superior in terms of linking many pieces of information to a given source on the image and being able to interactively select sources either on the image or in the catalog. Regions can’t do any of this, you have to find a way to plot the info on the image (or a star name and then look up additional info via the star name, etc.) and you can’t filter on regions interactively as you can in the catalog tool.

The catalog tool’s lack of support for image coordinates seems like it would be simple enough to implement, and I will definitely file a feature request. Adding RA/Dec to my custom catalog is possible but painful (no WCS on the images, ground-based images, small fields of view, no reference stars). I can do it, but I would vastly prefer to work in pixels for completely unrelated reasons (high-precision astrometric and photometric measurements often depend on pixel phase or detector location). I will definitely give TOPCAT a try with ds9 and I haven’t revisited Aladdin in a couple of years, so that deserves another look as well.

Tigran: would you describe Starlink/ESO Skycat as easy to learn?