M81 & M82 - how much IFN should be shown?

[gorann]

Here I set out to see how much IFN (Integrated flux nebulas) I could capture with the RASA in a few hours. The area around M81 and M82 are by now well known for its prominent IFN, although it is still a very faint form of nebulosity. I actually captured more than looked good as it seemed to drown the nice galaxies in there. So ihere are two versions as I had difficultes deciding how much IFN to show. None of them show all the IFN signal that is in the data, that looked just too overwhelming.

 

This is what Widipedia writes about IFN: Integrated flux nebulas are a relatively recently identified astronomical phenomenon. In contrast to the typical and well known gaseous nebulas within the plane of the Milky Way galaxy, IFNs lie beyond the main body of the galaxy.

The term was coined by Steve Mandel-Wilson who defined them as "high galactic latitude nebulae that are illuminated not by a single star (as most nebula in the plane of the Galaxy are) but by the energy from the integrated flux of all the stars in the Milky Way. These nebulae clouds, an important component of the interstellar medium, are composed of dust particles, hydrogen and carbon monoxide and other elements."

 

Captured 11 Feb with the RASA 8 and ASI2600MC, no filter. 71 x 4 min at gain 100, so 4.7 hours. Stacked in PI and processed in PS and PI.

[jetstream]

Excellent Goran.

If we tone down the results from the first image it would simulate how I see IFN, confirmed in one spot near Vega and strongly suspected in another place. I've been trying on and off in M81/M82 area for a long time but nothing confirmed.

I absolutely need to see an edge to have any hope on these. Your image gives me a new spot to try...

Keep them Coming Goran!

[gorann]

2 minutes ago, jetstream said:

Excellent Goran.

If we tone down the results from the first image it would simulate how I see IFN, confirmed in one spot near Vega and strongly suspected in another place. I've been trying on and off in M81/M82 area for a long time but nothing confirmed.

I absolutely need to see an edge to have any hope on these. Your image gives me a new spot to try...

Keep them Coming Goran!

Thanks Gary! Are you trying to see it visually?

[jetstream]

Just now, gorann said:

Thanks Gary! Are you trying to see it visually?

Yes, for years lol!

It takes true dark adaptation, no TV, no bright sunlight during the day and my best skies to see this kind of thing. I can see "texture" in the sky in many places, kind of a liquid grey mottled form and big. I decided to put a name to this and some of it is IFN I believe, other parts are just forms of dust (I think).

The galaxy on the far left in your image is my next spot to try.

Btw- what I see has variously been described as noise, brain filling in information and illusion lol!

I see Barnards Loop no filter but so far my limit is the Eridanus Loop... so far no go. I know IFN is different but I mentioned for reference.

[ollypenrice]

One of the many nice things about AP is that you can choose what your image is about. I would just do as you've done and post two versions. This applies to lots of targets: do we want Ha in a Double Cluster image? I do and I don't so I made both. 

I don't feel, in your case, that the stronger IFN detracts from the galaxies in any case. Very good image!

Olly

Edited February 16, 2021 by ollypenrice

[tomato]

Excellent images Goran. As you might have guessed I am not a fan of IFN, I would call it IGS (Inter Galactic Smog) as  IMHO it can detract from the galaxies. However, it is part of the Cosmos and not man-made LP and I do respect the skill and dedication of the imagers who have captured it.

 Gerry, I do admire your dedication (and eyesight) in your efforts  to observe it visually.

Steve

[gorann]

4 hours ago, ollypenrice said:

One of the many nice things about AP is that you can choose what your image is about. I would just do as you've done and post two versions. This applies to lots of targets: do we want Ha in a Double Cluster image? I do and I don't so I made both. 

I don't feel, in your case, that the stronger IFN detracts from the galaxies in any case. Very good image!

Olly

Thanks Olly! I fully agree that we should more often, at least here on SGL, post more than one version of our images. It is just so hard to decide, like inkluding Ha or not, and how much, or how much IFN. Not sure why we often feel we need to come up with one "ultimate" version when there are so many ways to present the data. Seeing more than one version is more interesting and provoking, so let's go for more diversity also in AP!

[gorann]

2 hours ago, tomato said:

Excellent images Goran. As you might have guessed I am not a fan of IFN, I would call it IGS (Inter Galactic Smog) as  IMHO it can detract from the galaxies. However, it is part of the Cosmos and not man-made LP and I do respect the skill and dedication of the imagers who have captured it.

 Gerry, I do admire your dedication (and eyesight) in your efforts  to observe it visually.

Steve

Thanks Steve! I can see your point and from a purely aesthetical point of view these two galaxies look better without IFN in my mind (at least right now). It is the same for me with Ha in galaxies. I often think those blotches of sharp red makes them look rather ugly and unnatural, but some likes them apparently and I have posted a few galaxies in RGB and got comments about having to add Ha. But then I think that adding a bit of Ha lifted my recent RASA version of M31.....

Edited February 16, 2021 by gorann

[gorann]

Here is a third version where I have added about 40% Esprit 150 refractor data from October to M81 and M82. It sharpened them up a bit but a surprisingly little difference even if you are a pixel peeper like me😁

Edited February 17, 2021 by gorann