I saw that there’s a new paper that has just been published in the journal Science by Umehata et al with the title Gas filaments of the cosmic web located around active galaxies in a protocluster. In case you run into a paywall at Science, you may of course, find the paper on the arXiv here.
The abstract reads:
Cosmological simulations predict the Universe contains a network of intergalactic gas filaments, within which galaxies form and evolve. However, the faintness of any emission from these filaments has limited tests of this prediction. We report the detection of rest-frame ultraviolet Lyman-alpha radiation from multiple filaments extending more than one megaparsec between galaxies within the SSA 22 proto-cluster at a redshift of 3.1. Intense star formation and supermassive black-hole activity is occurring within the galaxies embedded in these structures, which are the likely sources of the elevated ionizing radiation powering the observed Lyman-alpha emission. Our observations map the gas in filamentary structures of the type thought to fuel the growth of galaxies and black holes in massive proto-clusters.
The existence of a complex cosmic web of filaments and voids has been known about for some time as it is revealed on large scales by the distribution of galaxies through redshift surveys:
You can see all my posts agged with `Cosmic Web’ here. There are also good theoretical reasons (besides numerical simulations) for believing this is what the large-scale distribution of matter should look like. Roughly speaking, dense knots of matter lie at the vertices of a three-dimensional pattern traced out by one-dimensional structures.
We have also known for some time, however, that there is more going on in cosmic structure than is revealed by light from stars in galaxies. In particular the way gas flows along the filaments into the knots plays an important role in galaxy and cluster formation. This paper reveals the distribution of gas around a giant cluster that has formed at such a node using observations made using the European Southern Observatory’s MUSE instrument.
Here’s a pretty picture:
I found out about this paper from a news piece in the Guardian with the title Scientists observe mysterious cosmic web directly for first time. That’s sufficiently misleading for me to cross-file the paper under `Astrohype’ because, as I explained above, we have been observing the cosmic web for decades. It is however only just becoming possible to observe the diffuse gas rather than having to join the dots between the galaxies so it is an exciting result. My complaint, I suppose, is that the word `directly’ is doing a lot of heavy lifting in the title!
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This entry was posted on October 4, 2019 at 3:46 pm and is filed under Astrohype, The Universe and Stuff with tags arXiv:1910.01324, Cosmic Web., Cosmology, European Southern Observatory, galaxies, galaxy clusters. You can follow any responses to this entry through the RSS 2.0 feed.
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