Can life survive in the a galaxy's bulge? Between galaxies?

[gib65]

I've heard of a goldilocks zone for solar systems--a region around the solar system's sun that's not too close and not too far away from the sun for life to thrive--but is there a similar concept for galaxies? For example, could a solar system capable of sustaining life exist deep within the central bulge of a galaxy? Or would that region be too hot? Similarly, could a solar system exist far outside a galaxy and still be capable of sustaining life? It might be significantly colder in the empty space between galaxies but the solar system's sun could provide all the heat life needed, couldn't it?

[mistermack]

Without doing any research, I would say that it wouldn't be heat that would be the problem, but radiation. Even in the central bulge, the nearest star is likely to be just a tiny speck in the sky, the distances are so vast. So direct light irradiation from neighboring stars wouldn't be a problem, but I vaguely remember reading that damaging cosmic radiation levels would be too high for life to exist.

[Moontanman]

11 hours ago, gib65 said:

I've heard of a goldilocks zone for solar systems--a region around the solar system's sun that's not too close and not too far away from the sun for life to thrive--but is there a similar concept for galaxies? For example, could a solar system capable of sustaining life exist deep within the central bulge of a galaxy? Or would that region be too hot? Similarly, could a solar system exist far outside a galaxy and still be capable of sustaining life? It might be significantly colder in the empty space between galaxies but the solar system's sun could provide all the heat life needed, couldn't it?

There is a Galactic Habitable Zone or at least such a zone is hypothesised to exist. I see no reason an intergalactic star couldn't have planets that support life. 

[Airbrush]

"The concept of a galactic habitable zone analyzes various factors, such as metallicity (the presence of elements heavier than hydrogen and helium) and the rate and density of major catastrophes such as supernovae, and uses these to calculate which regions of a galaxy are more likely to form terrestrial planets, initially develop simple life, and provide a suitable environment for this life to evolve and advance."

Galactic habitable zone - Wikipedia

The Goldilocks Zone is where there are enough supernovae to create heavy elements that life needs, BUT not too many supernovae because they also destroy life on planets.  Generally, there are more supernovae, and therefore deadly radiation, near the center of the Milky Way, and in the densely-packed spiral arms.  In sparsely populated regions there are not enough supernovae.

Edited January 5, 2023 by Airbrush

[AZZLE]

In my opinion, the goldilocks zone also depends on the distance from the quasar in the center of our galaxy. If I'm not wrong, the galactic nuclei has a black hole which might emit radiation having some affects on the zones nearby or avoiding it to be in the goldilocks.

 

[Airbrush]

On 4/5/2023 at 8:08 AM, AZZLE said:

In my opinion, the goldilocks zone also depends on the distance from the quasar in the center of our galaxy. If I'm not wrong, the galactic nuclei has a black hole which might emit radiation having some affects on the zones nearby or avoiding it to be in the goldilocks.

 

If the center of OUR galaxy had an active quasar, that would make it even worse for life in the central region.  But you don't need an active galactic nucleus to suppress life.  All you need are plenty of supernovae going off, and that is what happens in the dense regions of any galaxy.

[mistermack]

Of course, a lot would depend on the type of life, and it's environment. For instance, what if life originated under miles of ice, at the bottom of a very deep ocean. What kind of cosmic radiation could affect that? ( I don't know the answer to that, I'm just posing the  question ).

A lot of people contend that life on Earth originated very deep in the ocean, so that could be the case elsewhere too.  

But a highly irradiated part of the Universe might be impossible to explore in space craft and not worth the effort. So it could be that there is life in hostile parts of the galaxy, but it remains primitive, deep in an ocean, and not of much interest.