Centaurus A in Halpha - now also in HaLRGB :-)

[Slawomir]

Hi all,

This time I am sharing fruits of an experiment that was quite out of my comfort zone - Cent A in Halpha.

A crop: http://www.astrobin.com/full/249121/None/

Full frame: http://cdn.astrobin.com/images/thumbs/819f4afdfac6078d3929518bad2c5537.16 536x16536_q100_watermark_watermark_ opacity-3_watermark_position-6_watermark_text-Copyright%20Slawomir%20Lipinski.jpg


In spite of mediocre result, it was quite interesting to spot a few background galaxies starting to emerge even with 3nm filter. I have also attached a record of progression for this project (data collected over 4 sessions) and a comparison of a standard integration vs drizzle integration (native 1.33" per pixel vs 0.66" per pixel).


Thank you for looking
Suavi

EDIT: Now HaLRGB with Lee's awesome LRGB data: http://www.astrobin.com/full/249121/E/

[Atmos]

That is a really interesting project Suavi, I was considering doing something similar with NGC 6744 last night but it clouded over (every weather site said it was clear!).

What I find interesting is that in the high res, it begins to appear as if it has a donut shape, ie. round. Has a bit of a 3D feel to it.

Drizzle integration really is a very good thing when you are sampling close to seeing conditions.

[alpal]

Hi Suavi,
you've also picked up the jet quite well.
Drizzle works well on small targets.

cheers
Allan

[Placidus]

A wonderfully successful experiment, Suavi.

In your H-alpha image, the jet appears to be a much longer, more coherent, single entity, whereas in colour shots it's more of a couple independent streaks.

Brilliant!

Given that in colour shots the jet tends to be blue, I wonder if it shows specifically OIII emission, or whether the blue has some other origin, like the blue synchrotron radiation on the Crab nebula.

[RobF]

I love it when someone does something that makes me see an "old" object in a new way. Your Ha data is the first time I've sensed the prominent dust circling back around a central glowing nebulosity. In LRGB the dust bar seems "just there" rather in an otherwise smashed-up (but spectacular) galaxy.

Maybe its just an illusion of the direction of the image or Ha, but its still a fascinating shot Sauvi.
You obviously also revel in the technical challenge of wringing ever last % from your gear too. :)

[Slawomir]

Thanks Colin. I thought it would be interesting to see this galaxy in narrowband. Hopefully you will get a few clear nights to try it on NGC 6744 :)



Thank you Allan. There isn't that much signal in the subs, but eventually the jet started forming with increased integration. Would love to have darker skies as it would lower the noise quite significantly...drizzle IMO can be a brilliant tool and I am planning to use it more often :)



Thank you Mike and Trish for your kind feedback. I was hoping to leave it as is but since you have mentioned OIII I am now being tempted to try it as well :lol:



Thank you Rob! I usually, often without realising it, present astro images upside-down :lol:

[Atmos]

Do I hear a SHO NGC5128 coming up? :lol:

[RickS]

Very cool, Suavi! A novel view of an old favourite.

[codemonkey]

Great data mate! Thanks for sharing :D

[strongmanmike]

This is so funny Suavi, last night when I made my quick decision to go out to my observatory I was contemplating what to image as I was driving out and one of the things I thought was "I should do a couple of hours of Ha on Cen A and add it to my latest effort on the galaxy, that might be interesting?" ...and today you post this! :lol:

Great idea, have you got an LRGB to add this to?

Mike

[Slawomir]

You might have picked on my brainwaves, I hope you are okay :lol:

Lee has very kindly shared with me his LRGB data, so I will try processing it sometime next week.



No problemo. It is nice that you implemented it in your image and IMO you did a great job combining narrowband data with your LRGB :thumbsup:



Thank you Rick.



That could end up as a disaster image, but could be interesting too :lol:

[Paul Haese]

What I find most interesting about this image and in particular the full res version is about 3/4 toward the bottom corner is a rather long extended streak which I think coincides with the position of the jet. It is much further down than the other more prominent optical jet. I have not seen that in an amateur image before. Keep going and see what transpires.

[Slawomir]

Thank you Paul for encouragement. I was thinking of trying OIII with this target, but may try to collect some more Ha first to further bring the noise down and hopefully to show the jet more clearly.

For reference, here is a link to an ESO image showing this jet very nicely: https://www.eso.org/public/australia/news/eso1221/

[strongmanmike]

..?..of course. I am! :nerd: :face:



And his effort with it looks good...kind of glad I didn't spend my time on it now, t'is just as good to sit back and watch you guys work with it :thumbsup:

Mike

[Slawomir]

Made an attempt to also put together Lee's awesome LRGB data with my Ha: http://www.astrobin.com/full/249121/E/

[codemonkey]

Nice work Suavi! You've done a better job keeping the stars a bit tighter than I did, and did much better integrating the Ha data. Mine's a little too out there in the dust, and not as visible as yours is in the jets. Well done, you'll have to fill me in on how you ended up blending the Ha with the LRGB.

[Slawomir]

Thank you Lee! It has been a steep learning curve for me putting together HaLRGB data - I normally only do pure narrowband! I am truly grateful Lee for your data and for our collaboration.

Your interpretation has MUCH better colours, for me personally a benchmark to aim for :) I think I now know at which stage I could have done better (colour calibration tool).

As for integrating Ha data, well I did not bother with star removal from Ha and simply used pixelmath to add your Lum with 3xHa. More than 3xHa was showing too much noise and did not seem to add more detail to Lum. I also did a gentle noise reduction with TGV Denoise on all masters at the start though - my Ha needed that in particular.

Now I have a bit of a dilemma- collect some more Ha and see if that helps with showing the jet, or move onto something else. I also thought that having OIII and adding that to Green could also potentially show new structures within the galaxy. HaOIIILRGB - that would be something!

[billdan]

The colour combo looks really good Suavi, those jets do really stand out, I went and had a look my old images but could not see any in the OSC colour data.

Its hard to imagine any OIII data in there, but give it a go if you have the time.

Cheers
Bill

[Slawomir]

Thank you Bill.

Now waiting for the moonlight to ease a bit before returning to this project. I think I will get some more Ha first, until noise drops to what I consider a reasonable level, so then I could keep the data ready for next year :)

[rustigsmed]

nice work suavi,

didn't think there would be that much Ha in there, excellent that you have given up other potential 'safe' targets and invest in this. it has been well worth it, i like both yours and Lee's Ha - LRGB combos.it definitely adds to the usual image, the only downside is now everyone is going to have to add atleast Ha to their galaxy pics from now on!!!!!!!!!!!!!!!!!!!!