M31 bathing in ionised Hydrogen

[Cozzy]

Absolutely stunning image Peter, beautifully processed, you have to be pleased with an outcome like that, triple 🍑 🍑🍑.

 

Tim

[wimvb]

Excellent capture Peter. The red isn't actual Hydrogen-alpha emission, but so called extended red emission from interstellar dust. Small particles (molecules rather than hydrogen atoms) absorb high energy light from (stars in) our galaxy and re-emit it as lower energy red light, a process called photoluminescence. The spectrum of this emission is much wider than Ha emission. (So a wider band nb filter should capture it better than a narrow nb filter.)

https://iopscience.iop.org/article/10.1086/305571/fulltext/

One reason we normally don't see it in images is the way we calibrate colours. Unless done very carefully, PixInsight background neutralization for example, would obliterate it. The emission is extremely weak.

[bob-c]

An absolute corker Peter 👍

 

Bob.

[peter shah]

7 hours ago, Cozzy said:

Absolutely stunning image Peter, beautifully processed, you have to be pleased with an outcome like that, triple 🍑 🍑🍑.

 

Tim

Cheers Tim

2 hours ago, wimvb said:

Excellent capture Peter. The red isn't actual Hydrogen-alpha emission, but so called extended red emission from interstellar dust. Small particles (molecules rather than hydrogen atoms) absorb high energy light from (stars in) our galaxy and re-emit it as lower energy red light, a process called photoluminescence. The spectrum of this emission is much wider than Ha emission. (So a wider band nb filter should capture it better than a narrow nb filter.)

https://iopscience.iop.org/article/10.1086/305571/fulltext/

One reason we normally don't see it in images is the way we calibrate colours. Unless done very carefully, PixInsight background neutralization for example, would obliterate it. The emission is extremely weak.

That's really interesting.....thank you for the info

1 hour ago, bob-c said:

An absolute corker Peter 👍

 

Bob.

Thank you Bob

[peter shah]

With this version I have done some work on the background Luminance layer. It has additional structure in the Luminance that I thought would be worth showing

[Spikey]

A truly fascinating image Peter and well worth the enormous amount of effort you've clearly gone to.

[tooth_dr]

Really different take on M31, and truly fascinating Peter, thanks for sharing this for all to enjoy.

[gorann]

14 hours ago, wimvb said:

Excellent capture Peter. The red isn't actual Hydrogen-alpha emission, but so called extended red emission from interstellar dust. Small particles (molecules rather than hydrogen atoms) absorb high energy light from (stars in) our galaxy and re-emit it as lower energy red light, a process called photoluminescence. The spectrum of this emission is much wider than Ha emission. (So a wider band nb filter should capture it better than a narrow nb filter.)

https://iopscience.iop.org/article/10.1086/305571/fulltext/

One reason we normally don't see it in images is the way we calibrate colours. Unless done very carefully, PixInsight background neutralization for example, would obliterate it. The emission is extremely weak.

Amazing image Peter!

Rogelio Bernal Andreo, who calls it Clouds of Andromeda, has a more popular article about it and also suggests that it is not Ha but wider emission that includes the Ha part of the spectrum.

https://www.deepskycolors.com/archive/2017/01/01/Clouds-Of-Andromeda.html

Edited July 27, 2021 by gorann

[peter shah]

1 hour ago, gorann said:

Amazing image Peter!

Rogelio Bernal Andreo, who calls it Clouds of Andromeda, has a more popular article about it and also suggests that it is not Ha but wider emission that includes the Ha part of the spectrum.

https://www.deepskycolors.com/archive/2017/01/01/Clouds-Of-Andromeda.html

Thanks Goran, It was this image that prompted me to give it a go....😉....

[wimvb]

1 hour ago, peter shah said:

Thanks Goran, It was this image that prompted me to give it a go....😉....

So, very likely there is ERE around M33 as well. Fancy a challenge? 😋 (I can blame lack of astro darkness for another month or so)

[peter shah]

9 minutes ago, wimvb said:

So, very likely there is ERE around M33 as well. Fancy a challenge? 😋 (I can blame lack of astro darkness for another month or so)

Absolutely.... I have already started planning my subs for M33 a couple of days ago 😉....

[Lee_P]

Thanks for sharing, it's a treat to see an unusual view of such an iconic and much-imaged DSO!

[Roy Foreman]

The first version was great, the second one even better.  Looking forward to see what you can do with M33 !!!