PixInsight Forum (historical)

PixInsight => Gallery => Topic started by: ngc1535 on 2014 July 15 01:12:56

Title: Arp 30 (Depth Perception)
Post by: ngc1535 on 2014 July 15 01:12:56

Hi all,

This amounts to my first PI (alone) processed image:

http://skycenter.arizona.edu/gallery/Galaxies/NGC6365

I cannot stress how small these guys are! For those unfamiliar with my work, these images are intrinsically 0.33 arcseconds per pixel.

I have plenty to learn and I appreciate the support from the community with regards to questions I hope can be answered as I experiment and find my way.

The caption I wrote when I release this image is below:

Depth Perception:

Here is a beautiful pair of galaxies:

http://skycenter.arizona.edu/gallery/Galaxies/NGC6365

The bright luminaries of the picture are of course foreground stars and the galaxies, perhaps equal in size to our own, are more than 350 million light years away. At this distance they are very small on the sky (about 1 arcminute) such that detailed images of them are difficult to attain. The question this picture poses is one of depth. Are the galaxies actually very close? Since they do not appear grossly distorted a few million light years could very well separate them. The reddened portions of the spiral galaxy also hint that the vertical one is in the foreground. These are the kinds of questions that are answered by more precise measurements that unfortunately a pretty picture cannot reveal. That being said, images like this colorfully highlight the vastness of the Universe.

Sincerely,
Adam

Title: Re: Arp 30 (Depth Perception)
Post by: Geoff on 2014 July 15 13:02:13

Beautiful image Adam.  Welcome to the world of PixInsight.
Geoff

Title: Re: Arp 30 (Depth Perception)
Post by: JoLo on 2014 July 18 08:25:37

Very nice Adam, looks like they are doing a cosmic dance.

Joe

Title: Re: Arp 30 (Depth Perception)
Post by: Alejandro Tombolini on 2014 July 21 18:06:38

Hi Adam, very beautiful image!!.
There is a sat trail and some hot pixels in the red channel that could be removed if you decrease sigma high in Pixel rejection in ImageIntegration tool (I assume you have used Winsorized Sigma Clipping as Rejection algorithm).
You also may want to reduce chrominance noise using MultiscaleLinearTransform selecting Chrominance as Target and adjusting k sigma Noise Threshold, rest as default. Attached is the process.
Saludos, Alejandro.