Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

Another assault on the IFN.

ollypenrice

By ollypenrice
in Imaging - Deep Sky

Recommended Posts

ollypenrice

ollypenrice

Posted
Posted

Inspired by the impressive M81/82/IFN by André, Neil and Michael I wondered if I'd learned enough in the last couple of years to find a bit more in my existing data. This was about 19 hours LRGB in the dual Tak 106 rig plus some resolution enhancement from the M81/82 I did with Yves at long focal length. And, yes, I think I found a bit more. I doubt that IFN images are ever going to win 'subtle processing' awards because you have to prize the stuff out with a crow bar, or at least I do. Probably somewhat OTT so I may settle on an old-new blend in the end but here we go with the gung-ho version!

IFN%20M81%20M82%20Widefield%20web-L.jpg

Olly

Link to comment
Share on other sites
gorann

gorann

Posted
Posted

Amazing image Olly! Very inspiring.

The only thing I cannot get my head around is that the galaxies seem to be in front of the dust, but I assume the dust is part of our galaxy and they just happen to be in some openings in the dust so we can see them, or am I wrong and this is intergalactic dust?

Link to comment
Share on other sites
Daniel-K

Daniel-K

Posted
Posted

fantastic image Olly. i have a question if  i collected x amount of data on M81 & M82 but the amount of data was not enough to pull the IFN out but the IFN was in the data would the IFN look like noise? or would it just be lost in the blacks?

Link to comment
Share on other sites
ollypenrice

ollypenrice

Posted
  • Author
Posted
27 minutes ago, Daniel-K said:

fantastic image Olly. i have a question if  i collected x amount of data on M81 & M82 but the amount of data was not enough to pull the IFN out but the IFN was in the data would the IFN look like noise? or would it just be lost in the blacks?

FIrstly I reckon that the IFN is a dark sky target. I doubt that much of it could be separated from significant LP. 

Next I'd look for Holmberg IX in the data. That's the dwarf irregular galaxy next to M81. If you haven't got that then the IFN surely won't be possible.

Going one step fainter, there's Arp's Loop around M81. This may be part of the IFN, though it has also been interpreted as a tidal feature drawn from M81. In any event it's a little brighter than the rest of the IFN and so should tell you whether or not to keep searching. See the link at the end.

Would it look like nolise? Probably, though it should in principle be a tiny bit less noisy than the background since it has just a whiff more signal.

 

9 hours ago, gorann said:

Amazing image Olly! Very inspiring.

The only thing I cannot get my head around is that the galaxies seem to be in front of the dust, but I assume the dust is part of our galaxy and they just happen to be in some openings in the dust so we can see them, or am I wrong and this is intergalactic dust?

Good point. I think the impression of 'foreground galaxies' simply comes from the fact that they greatly out-shine the IFN and overwhelm its signal. We've seen this effect before. There's the extended arm of M51 which passes in front of its campanion and disappears as it does so, only to become visible again once past it.

The mighty R Jay GaBany discusses Arp's Loop and the IFN here.  http://www.cosmotography.com/images/small_ngc3031.html

It won't be intergalactic dust because any such dust would have nothing to illuminate it.

Olly

Link to comment
Share on other sites
Pompey Monkey

Pompey Monkey

Posted
Posted

You're right Olly: " It really is out there. "

That image is absolutely amazing but I agree, after downloading the larger image from your website, that you really have scraped the signal of the top of the noise for this one. Top processing indeed.

I guess it's been raining at Les Granges too ;)

Link to comment
Share on other sites
ollypenrice

ollypenrice

Posted
  • Author
Posted
1 hour ago, Pompey Monkey said:

You're right Olly: " It really is out there. "

That image is absolutely amazing but I agree, after downloading the larger image from your website, that you really have scraped the signal of the top of the noise for this one. Top processing indeed.

I guess it's been raining at Les Granges too ;)

Nope, it's been very clear but His Brightness has been keeping me indoors! Back to work any time now though.

This isn't really an image to hold up to full size scrutiny. I normally aim for presentation at 1 to 1 or very nearly, but here I think it's only the broad structures we're looking at so I thought I'd get the crow bar out and settle for a smaller format.

Olly

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.