Astronomers Using ALMA Spot Monstrous Baby Galaxies In Dark Matter Filaments - Using the facilities at ALMA Observatory in Northern Chile,
astronomers have found monstrous baby galaxies located around 11.5
billion light-years from Earth.
American theoretical physicist and Harvard University Department of Physics professor Lisa Randall,
author of the new book “Dark Matter and the Dinosaurs: The Astounding
Interconnectedness of the Universe”, says dark matter protects galaxies
from radiation.
Without the poorly understood invisible material, “radiation would have washed away galaxies,” she said.
In a Big Think presentation (see the video below this article),
Professor Randall says the abundant nonluminous material was essential
to the creation of structures we see in the Universe today. Even without
dark matter, structures including the Earth, the Sun and other stars
and planets would have formed. But Professor Randall points out that
“the actual size of the galaxies we see is only possible because dark
matter was present.”
About ten billion years before the formation of the Solar System,
apparently including the Earth, many areas in the Universe were
inhabited by monstrous galaxies that make hundreds or thousand of times
more stars than what we observe today in the Milky Way. In the modern
Universe, there aren’t any monstrous galaxies left, but some astronomers
believe that these monstrous structures have matured into giant
elliptical galaxies.
Astronomers have theorized that these monstrous galaxies form in
areas within the known universe where there are concentration of dark
matter. But up until now, observing these galaxies has been a problem.
Part of the problem, they say, is that monstrous galaxies that
manufacture lots of stars are often obscured in dust, making them
difficult to observe in visible light. Galaxies covered in dust emit
strong radio waves with submillimeter wavelengths, but radio telescopes
typically have not had the resolution needed to locate individual
galaxies.
Today, a group of researchers say they’ve located some massive baby
galaxies undergoing energetic star formation, at the dawn of our known
Universe. The team led by Hideki Umehata, a postdoctoral fellow of
the Japan Society for the Promotion of Science, and Yoichi Tamura
and Kotaro Kohno from the University of Tokyo, have used the ALMA, or
the Atacama Large Millimeter/submillimeter Array in Chile to make
extensive observations of a small part of the sky known as the SSA22,
located in the constellation of Aquarius.
Before using the ALMA facilities, the team have searched for the
so-called “baby galaxies” in the region using the ASTE, a 10-m
submillimeter telescope operated by NAOJ, or the National Astronomical
Observatory of Japan.
Using the ASTE, the team could see indications that “there might be” a
cluster of monstrous galaxies in the SSA22. So they’ve scanned the area
using the ALMA to pinpoint the locations of the nine very
young monstrous galaxies.
The team then compared the positions of the baby galaxies with the
location of the clusters of young galaxies 11.5 billion lightyears away
in the SSA22 which had been observed in visible light by the Subaru
Telescope (in Hawaii). The shape of the cluster observed using the
Subaru Telescope indicates the presence of a huge 3D web of dark matter
in the area.
The team said they’ve found that the nine monstrous baby galaxies
“seemed to be located right at the intersection of the dark matter
filaments”, and this finding supports the theory that monstrous galaxies
form in areas with dark matter concentration.
In a press release, the group says their discovery
is a very important step for the comprehensive understanding of the
link between the distribution of dark matter in the universe and
monstrous galaxies. Moving forward, the team says they will search for
more monstrous galaxies “to look back even farther into the early
history” of the Universe, and to see how these observable structures
have evolved with dark matter.
This scientific article was published
in the Astrophysical Journal Letters on December 4, with the
title “ALMA Deep Field in SSA22: A concentration of dusty starbursts in a
z=3.09 protocluster core.” Source: StGist
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