'Galaxy fingerprinting' yields new clues about galaxy evolution


Astronomers are a step closer to understanding the evolution of galaxies, thanks to new research that compares the chemical make-up of distant galaxies to those in our own galactic back yard.

Trystyn Berg, a PhD candidate in physics and astronomy at the University of Victoria, is studying the inner workings of distant created during the first three billion years of the universe. But how do you study in detail something that is over 50 billion light-years away?

"We can't see individual stars in these galaxies because they're too far away even for the most powerful telescopes," says Berg, who uses a technique that takes advantage of stars releasing their gaseous products when they explode.

"Stars are the cauldrons of the universe," he explains. "They create the elements we're made of. They consume their fuel and release the products back into the galaxy during supernova explosions."

Depending on the properties of a galaxy, its chemical contents can tell us how the galaxy evolved over time, how many stars it has, and what types of stars it has made. To get this information, researchers look for distant, intense points of light known as quasars that have galaxies in the foreground.

"All of the gas within the galaxy will absorb some of the background quasar light, leaving a fingerprint of which elements are within the galaxy," says Berg. "This chemical fingerprint can give us some very useful clues about the evolutionary history of the galaxy."

Despite a wealth of data collected in this way from distant galaxies over the past decade, no one has done a detailed comparison to what's seen in . Until now, that is.

Using observations made with the Keck telescope—one of the largest optical telescopes in the world—Berg and collaborators observed 30 distant galaxies, adding to the previous sample of 310 galaxies. With the additional observations, they were able to compare the chemistry in distant galaxies to nearly 2,000 stars within six nearby galaxies, including the Milky Way.

"We found that many of the distant galaxies are similar to low-mass galaxies in our neighborhood," says Berg. "It's incredible to see, in the short time of three billion years, how quickly it took the universe to make the building blocks of the Milky Way system."

Says Berg: "These observations are stepping stones that allow us to tag which early galaxies the of modern galaxies came from. We still don't have an understanding of how parts of the Milky Way system formed, and our results now tell us what chemistry to go look for to answer this question."

Explore further

The kinematics of merging galaxies

More information: Berg presented these results at the 2015 meeting of the Canadian Astronomical Society / Société Canadienne d'Astronomie (CASCA) in Hamilton, Ontario (www.physics.mcmaster.ca/casca2015/?page_id=2).
Citation: 'Galaxy fingerprinting' yields new clues about galaxy evolution (2015, June 1) retrieved 15 October 2019 from https://phys.org/news/2015-06-galaxy-fingerprinting-yields-clues-evolution.html

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Jun 01, 2015

Just another clueless merger maniac.

Jun 02, 2015
we can't see ANYTHING past that 13.8 billion light year mark

Hi, my education is pretty meager but I believe the current consensus of the diameter of the Observable Universe is 91 billion light years. While it's true the light we see is only ~13.8B years old the objects that emitted the light have increased in distance from us due to Dark Energy and the accelerating expansion of the Universe. I think this makes the furthest objects that we could see 45.5 billion light years away. While you seem to be technically right about not seeing 50billion ly distant objects I believe it is for the wrong reason. I could be mistaken and perhaps some lensing effect would allow us to peer even further away. Minute Physics on youtube has a pretty swell video on it if you prefer not to read.

Jun 02, 2015
The astronomers are not at all any closer "to understanding the evolution of galaxies" and they will never be closer if they depend on the "Big Bang" fairy tales.

The cellular and the organic like structure of the cosmos; the (quantized) shell like structure of both elliptical and spiral galaxies; the similarity of the chemical composition (and metallicity, iron content) of the quasars, of the inter-galactic media and of the near and far galaxies; the proper motion of the quasars; the quantization in the physical distribution and in the redshifts of celestial objects; etc., are greatly at odds with the notion of their origin in a "first impulse" The idealist trammels of a grand cosmic design of perfect symmetry, majestic beauty and divine serenity etc., envisioned by GR are nowhere to be found.

Jun 05, 2015
No, they have NOT "been seriously investigated"; they are just ignored! Well, official astrophysics and cosmology may ignore the findings of well known astronomers like Arp, Burbidge et al; but they also keep quite (no discussion at all!) or explain away some of their own uncomfortable findings. Only few examples below:
1) Just recent findings that only a few (if any) supernova (the measuring stick of distance) are not of the Type 1a and hence the luminosity measurements are not reliable.
2) How could heavy metals like Iron had time be cooked in quasars that are supposed to be at the periphery of the cosmos and formed at its early history and the intergalactic space is strewn with them?
3) Most of the galaxies (both elliptic and spiral) have discreet (quantized) ring or shell-like structure. David Malin and co-workers of Anglo-Australian Telescope found this phenomena in hundreds of galaxies they studied. I have seen no explanation for this and much more! Please see the next post.

Jun 05, 2015
@Jean Tate, the above post was in response to your comment

The dialectical view considers the universe to be infinite and eternal.
For a dialectical view about the origin, the evolution and the formation of the galaxies in the universe which is the exact opposite the Bid Bang theory; please see the following link and other publications by the same author on astrophysics and quantum dynamics, available through the internet.
The Dialectical Universe: http://www.amazon...40414445

Jun 05, 2015
@ Jean Tate:

You will find references in the link provided above (though bit outdated by now, and also some publications of Arp) and other publications by this author, if you search from Google in combination with terms like "galaxies", "quantum", "dialectical" etc. I must advise you that many of these publication (like those of Arp) are often in obscure journals, for the simple fact that no mainstream ones would even touch with a ten feet pole!
Re 1: Just see recent discussion in Physorg itself and references therein.
Re 2: I have no particular reference at hand, but should be available in the literature
Re 3. Malin et al. have catalogues of galaxies with shells (without any explanation); please see for example Ap. J. 274,(1983), Nature, 320(1986), 577
For "proper motion" of quasars please see Arp et al's work and references there.
Please ask me further questions only after going through some of the references I cited. Thanks
