Half of All Stars in Galactic Halos: Potential to Rethink Mass Estimates?

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The discussion centers on a claim that half of all stars are rogue stars located in faint halos around galaxies, a significant increase from the previously estimated 5%. If validated, this finding could prompt a reevaluation of galactic formation models due to the substantial amount of previously unaccounted mass. The implications extend to understanding light from these stars, which may complicate theories on reionization and halo sizes. The conversation also touches on the role of dark matter in making sense of these findings. Overall, this discovery could fundamentally alter existing estimates of galactic mass and distribution.
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I cannot get to the original Science publication to cite it. Science Now has a précis:
http://www.latimes.com/science/scie...ight-background-ebl-ciber-20141106-story.html

So the information below is not firsthand.

The claim is that one half of all stars are rogue stars, which are stars which well out into a very large, faint halo around galaxies. The article mentions that previously about 5% of all stars were thought to fall into this category.

It goes on saying that this finding, if validated, would cause researchers to revisit models of galactic formation.
Question: why would that cause reevaluation - a lot more previously unaccounted for mass? Does this finding have the potential to invalidate existing estimates of galactic mass?

Thanks for any comments.
 
Space news on Phys.org
Thanks for that.
 
jim mcnamara said:
Question: why would that cause reevaluation

From the article it looked more like a reevalution of how the light from these stars would inform on reionization (perhaps makes it even more difficult to understand) and halo size. The latter would have implications for masses and their distribution, I would think. I just scanned the provided paper, and it seems their models are based on LCDM, so presumably no problem there.
 
Dark matter is the short answer. Without it, nothing makes a whole lot of sense.
 
Abstract The Event Horizon Telescope (EHT) has significantly advanced our ability to study black holes, achieving unprecedented spatial resolution and revealing horizon-scale structures. Notably, these observations feature a distinctive dark shadow—primarily arising from faint jet emissions—surrounded by a bright photon ring. Anticipated upgrades of the EHT promise substantial improvements in dynamic range, enabling deeper exploration of low-background regions, particularly the inner shadow...
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
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