Centaurus A: What a Remarkable Sight

OTA: PW14
Camera: ZWO ASI2600MM
Observatory: iTelescope (free data)
Date of Capture: Apr '24
Date of Processing: May '24

Exposures Used:
R: 33 x 120 sec
G: 38 x  "
B: 30 x  "
Total Exposure time: 3.7 hours
Image Width: 31' 20"

Processing Tools:
1.    Commercial: PixInsight, Topaz, Radiant Photo, PhotoDirector
2.    Pixinsight Addons: NoiseXTerminator, BlurXTerminator, StarXTerminator
3.    My Scripts: NB_Assistant, AC_Restar, Subframe Weighting Tool (Excel w/ J. Hunt)

Target Description:
This galaxy both hosts a super-massive black hole and is a starburst galaxy. The black hole creates a jet perpendicular to the galaxy's plane. This image captures just a ting of that blue jet in the upper left corner of the image D. (Wikipedia)

The common reason for a starburst (an abundance of new stars being formed) is the gravitational interaction with another galaxy. Such interactions stir the interstellar clouds, and their subsequent collisions initiate density variations in the clouds and their gravitational collapse into stars. Notice the regions of blue young stars, especially along the edges of the dark equatorial dust cloud.

The equatorial dust cloud also has suffered a great deal of distortion and has been pulled into ropes and compressed into blobs. As an imager, what could be better: detail, detail, detail. This data set is the cleanest one of this object I have seen yet, and the details we can extract attest to that excellent image quality.

Processing Description:
I have long doubted the value of luminance subframes, so I finally got around to doing some comparative processing of RGB data with and without adding L. To my surprise, not only was there no benefit from the L, but it degraded the RGB image's detail resolution. Logically, that makes sense. Each color image has a restricted wavelength range, so an entirely red feature, for example, only appears in the red subs. The feature's photons are from red emission lines (e.g., Ha) plus red continuum. The continuum radiation, generally, is of minimal interest and carries little detail, so it softens the red image universally. The L has a continuum across this feature of interest, not only in the red continuum but in a continuum of all wavelengths. Thus, L softens the contrast and sharpness of the red feature more than occurs due to the bandwidth of the red filter. Hence, RGB images have greater sharpness and contrast than LRGB images. My write-up of this, with examples, is available here: https://www.astrobin.com/forum/c/astrophotography/deep-sky-processing-techniques/luminance-subframes-degrade-color-images-resolution-a-demo-and-explanation-of-why/.

Target Statistics:
Distance: 12M ly
Apparent Magnitude: 6.8
Pixel Resolution: 3.3"
Pixel Span at Target: 1.8E13 km

Alex Woronow