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About forty years ago, astronomers realized that our Milky Way is moving in space at a much faster speed than expected.
Our Milky Way is traveling through the universe at a speed of 2.2 million kilometers per hour, which is 2,500 times that of a cruise passenger plane; it is 55 times the speed of the earth's escape; it is even twice as fast as the Milky Way itself!
But where did this action come from now is a mystery.
Panoramic view of the entire near infrared sky. The location of the "Sum source" is displayed behind a long blue arrow in the lower right corner.
The Big Bang of Our Origin Theory tells us that every point in the universe should be separated from all other points. Nevertheless, the galaxies on both sides should move at similar backward velocities, which should result in no net motion in the Milky Way reference system.
net motion may come from nearby clumps in the material distribution, such as a huge galaxy cluster . The extra gravity of such a cluster can slow down or even reverse the expansion of the universe nearby.
But in the direction of movement of the Milky Way, such star cluster is not obvious. There are too many galaxies nearby and too much radiation visible in the X-ray telescope. But nothing seems to be big enough to explain the result.
So do we see that the density of pure dark matter is too high? Or is the current theory of mass and the origin of motion wrong? Alan Dressler, an astronomer at the Carnegie Institute, used the former explanation, which refers to the concentration of missing substances as " giant ingot ".
But another explanation may be that the direction of the inferred missing matter is not far from the direction of the coal bag nebula located deep in our Milky Way.
Hidden giant fountain
Will our own Milky Way move in space like a rotating disk at the edge, thus covering up the source of a distant giant fountain? Will there be a supermassive cluster of galaxies (which requires the equivalent of 10,000 Andromeda galaxies) somehow missed due to being obscured by dense dust layers associated with the thin disk of the Milky Way?
With this in mind, in the late 1990s, scientists began using an innovative instrument called the Parks multi-beam receiver on the iconic Parks telescope in NSW . The unique sensitivity and field of view of the receiver enable us to perform increasingly sensitive radio measurements of the sky.
These investigations were performed by adjusting the receiver to the so-called 21 cm neutral hydrogen wire. Although a faint line, the receiver is sensitive enough to detect thousands of galaxies in a "blind" investigation.
In addition, at radio wavelengths, radiation directly passes through the dust layer in the Milky Way. The Milky Way has basically become invisible.
HI Parkes Full-Sky Survey (HIPASS) conducted a shallow survey of the entire southern sky for the first time. In fact, HIPASS is the first sensitive sky survey conducted by any telescope on extra-river hydrogen. But no accidents were found behind the Milky Way.
other shallow investigations by the scientific team target the Milky Way itself. Only one mild galaxy is seen with super-density.
But people realize that deeper observation is needed. Theoretical models (particularly the so-called Lambda cold dark matter model) are only suspicious if they can find nothing within a distance of 200 million light-years.
So again, a series of deeper observations were made on the Milky Way disc and the local universe behind the bulge.
From the data
These were completed in the mid-2000s. Due to the additional difficulty in analyzing the galaxy radio data (there is additional noise generated by cosmic rays in our galaxy) and the dispersion of our team, all the data was not fully analyzed and submitted for publication until last year.
In the fifth degree of the galaxy disk, we found a total of 883 galaxies, and 77 were located in two parts of the Northern Milky Way visible from Parks.Only a few of these galaxies have previous optical redshifts, thus distance estimates.
However, when we look at the data from the new infrared survey and combine data from our own brand new deep infrared survey (infrared or thermal radiation is easier to pass through dust), we are able to confirm nearly 80% of the galaxies’ star counterparts. The rest are too deep embedded in the Milky Way to be confirmed with any existing optical or infrared telescope .
The discovery of many previously hidden galaxies has caused considerable excitement. But since we haven't found a big attractor, why are we still so excited?
It would be great if you think this is because the mystery has deepened. We do find new galaxies, clusters and new chains in the cosmic network. It's just not enough to explain our movement, so the "big attractor" that has this attraction to our galaxy remains a mystery.
I think most of the excitement is generated by simple acts that slightly uncover the universe, just like early explorers completing a blank map of the Southern Hemisphere.
Further explore
So what will happen next? Australian astronomers happen to be in the main position to further explore the structure and movement of the nearby universe. CAASTRO's 2MTF Sky Survey and other radio skysurveys also use Parks telescopes to calculate galaxy distances, which has made new contributions.
Baerbel Koribalski's co-principal investigator will begin performing later this year using the new CSIRO Australian SKA Pathfinder (ASKAP) telescope.
This will allow us to make huge progress in the detailed exploration of the radio universe, as will the square kilometer array (SKA) itself. At optical wavelengths, the Australian Observatory and Australia are leading a new survey called TAIPAN, which will target elliptical galaxies to explore more distant regions.
Theorists are also exploring whether the spatiotemporal metrics we use to describe the universe may no longer be valid, and whether general theory of relativity itself requires large-scale modifications.
is still too early, and a major shift in the cosmological paradigm requires irrefutable evidence. However, the mystery behind Great Attractor has lasted forever and may take a few more years to fully understand.
Source: universal-sci Translation: Decoherent
