NASA's Nancy Gracy Roman Space Telescope won't start operating until after the year 2027. Excited scientists are still dreaming about their new toy and all it will do. Who is responsible for them?
A new study examines the power of the Roman Space Telescope to see if it can help answer one of the most significant questions about the Universe. The question?
Is the Universe going to tear itself apart in a Big Rip?
NASA hasn't finalized the Roman Telescope's mission design. This study is to explore how they might modify it for the best results.
The study was published in The Astrophysical Journal. The lead author is a senior research scientist at Caltech. This study focuses on how the Roman Telescope will map the historic expansion of the Universe, and how it will have multiple tools.
The study shows how various adjustments could be made to the design.
The Roman will conduct a survey. The high latitude survey is the part of the study that deals with the spectroscopic part. One of the telescope's featured science objectives is the HLWAS. A high-volume precision survey of millions of galaxies dating back billions of years. Universal expansion over the Universe's history is the primary goal of the Survey. Science that isn't possible with other existing telescopes will be enabled by the HLSS.
The survey will offer clues about many other mysteries.
Universal expansion, Dark Energy, and Einstein's Theory of General Relativity are related to Roman's HLSS. These are deep and detailed topics, and they won't fit in a simple nutshell.
Nobody thought the Universe was expanding when Einstein put forth his TGR in 1915. TGR was able to explain things that Gravity couldn't. It had a flaw. Einstein's theory predicted that a static Universe had to either expand or contract in order to be stable. He tripped himself up by introducing the now-notoriouscosmological constant. He used it to achieve a static Universe. Einstein thought this was his greatest mistake.
Astronomers discovered in the 1920s that the Universe is expanding. The cosmological constant is going away. The rule describing the expansion is called Hubble's Law, and it was the work of an American astronomer. Belgian scientist and priest, Georges Lema, did earlier work on expansion, but he published his work in an obscure journal. Hubble's Law is now referred to as the Lema law. They found that all the galaxies are moving away from each other. The universe is expanding.
The expansion of the universe is a mystery. Scientists have a name for the force that is driving the expansion.
The expansion was thought to be slowing. It turns out that is not true.
Scientists discovered in 1998 that the Universe's rate of expansion is increasing. The gravity from all the matter should slow the expansion down. The constant came back into play after that discovery. It is the simplest explanation for the expansion. The Greek capital letter is lambda.
Wouldn't it be great if the guessing over the fate of the Universe was over? Lawrence Krauss thinks it would be fun to know how the Universe will end. Knowing what triggered its beginning would be fun. Imagine how popular you would be at cocktail parties.
The Roman Telescope has a high latitude survey. If the Universe will continue to expand and end in a Big Rip, the HLSS might be able to tell us.
The goal of the Survey is explained in the paper by the authors. There are two top-level questions.
There is no magic to this. There is brute force involved. The more you can measure the Universe, the more accurate your conclusions will be. The drive for larger, more precise telescopes like the Roman Space Telescope is behind this. The answers to our questions are more difficult to find.
The reference design for the HLSS is presented in the paper. About 5% of the sky will be covered by the Roman's HLSS in seven months. This is an improvement over other telescopes. Russell Ryan explained that Roman will allow us to sample thousands.
The deeper survey proposed here is a better complement to other surveys and more effectively exploits the capabilities of Roman.
A new study shows that Roman's HLSS should be able to measure 10 million galaxies from when the Universe was three to six billion years old. Astronomers will use that data to map the Universe.
The Roman Telescope's HLSS will take that mapping a step further by mapping the large-scale structure. When the Universe was only two to three billion years old, the HLSS will tell us the distances to about two million galaxies. That will be new data and is the first of its kind.
We have to measure as many things as we can. We can understand the history of the Universe if the Roman Telescope can bring new depth and breadth to our understanding. We will finally have our answer.
The authors wrote that Roman will determine the expansion history of the universe in order to test possible explanations of Einstein's gravity and dark energy.
The last sentence describes where we are now. The expansion of the universe is speeding up. The gravity of the Universe should be a drag on that expansion. Einstein's theory of gravity isn't exactly correct because of the acceleration. It means that we need to add a new energy component to the universe.
Einstein's gravity is correct to a point. Until we could see larger portions of the Universe, it was so. Einstein's gravity explains what happens on a larger scale than what is described byNewton's gravity. Our understanding is inadequate as we are confronting the entire Universe.
The Roman can bring something to the issue. The Roman Telescope's vast and deep 3D images of the Universe give a new opportunity to see between the leading theories that attempt to explain Cosmic Acceleration: a modified theory of gravity or Dark Energy.
Science can't win. Either result will get us closer.
The authors write that we need to measure two free functions of time: the expansion history and the growth rate of large-scale structure.
We can look forward to new physics if we discover that dark energy is the cause of Cosmic acceleration or if we modify Einstein's theory of gravity.
The High Latitude Wide Area Spectroscopic Survey is an example that could be used to implement the Roman survey.
Will we ever know how the Universe will end? We can talk about it at cocktail parties one day. The Nancy Gracy Roman Space Telescope helped us find our answer.