8

Ultra-deep radio telescope captures what Hubble can’t

“Hubble can only expose visible and near-infrared light; it can only see stars. But there’s much more to the Universe. Most of the normal matter in the Universe is present in the forms of plasma and neutral gas, not stars. Although Hubble cannot see this gas, it emits light nonetheless, just at longer (radio) wavelengths.”

The Hubble Ultra Deep Field and its successor images represent humanity’s deepest views of the stars in our Universe. But there’s more to the Universe than just stars; even the normal matter in the Universe is more commonly present in the forms of gas and plasma than in stars. Hubble can never image those so far away, since their wavelengths are too long. But the Atacama Large Millimetre/submillimetre Array (ALMA) can see exactly that. By tuning ALMA so that it was very sensitive to a particular emission feature at high redshift – a carbon monoxide (CO) emission line – astronomers were able to construct a radio deep field image at the same location where the Hubble Ultra Deep Field was. What they revealed was a composite image of the stars and gas, shown together for the first time, finding that the Universe’s neutral gas is in great abundance only at the highest of redshifts.

Find out what this teaches us about the distant Universe over on today’s Mostly Mute Monday!

The Everettian interpretation isn’t the only interpretation of quantum mechanics that results in a multiverse. Howard Wiseman, a theoretical quantum physicist at Griffith University, along with his team of colleagues, suggested the “many interacting worlds” approach. On this interpretation, each world is governed by Newtonian physics. However, given the interaction of these worlds, phenomena that are associated with quantum mechanics will arise. To test this approach, Wiseman suggested that the collision of two worlds could lead to the acceleration of one and the recoil of another; this would result in quantum tunneling. Wiseman and his team go through other examples, including the interaction of 41 classical worlds resulting in the type of phenomena observed in the double-slit experiment.

It was suggested that the multiverse could mark a paradigm shift. This could be the case because the multiverse is able to explanatorily absorb Big Bang cosmology. In other words, inflation, for example, though a property of the Big Bang theory, isn’t well understood without introducing the inflationary multiverse. For Big Bang cosmology to remain the paradigm, inflation would have to be explained without recourse to the inflationary multiverse. The multiverse, aside from explaining inflation, via string theory, can explain the behavior of dark energy. As mentioned earlier, as many as 10^500 phase changes of space have been proposed by string theorists.

As surveyed above, the Big Bang and the multiverse are self-contained, naturalistic explanations for the origin of the universe. There are, however, exotic explanations. One of the more recent suggestions offered by Niayesh Afshordi and his team is that the Big Bang was the result of a star that collapsed in a higher dimension. This four-dimensional star collapsed into a black hole. Interestingly enough, one of the properties of black holes is the singularity. The Big Bang, coincidentally, began as a singularity. Zeeya Merali explains: “When Afshordi’s team modeled the death of a 4D star, they found that the ejected material would form a 3D brane surrounding that 3D event horizon, and slowly expand. The authors postulate that the 3D Universe we live in might be just such a brane—and that we detect the brane’s growth as cosmic expansion.” This, Afshordi argues, led astronomers to extrapolate back to the early universe and reason that it must have begun in a Big Bang. According to Afshordi, the Big Bang is a mirage.

This brief survey offers the consensual explanation: the Big Bang; a good candidate to shift the current paradigm: the multiverse; and an exotic explanation: the universe resulted from the collapse of a four-dimensional star into a black hole. The survey is by no means exhaustive. There are, for example, many inflationary theories, e.g. hybrid inflation; inflation as is related to loop quantum gravity. There are also a number of theorems, e.g. quantum eternity theorem. The feature they all share, however, is that they represent a self-contained universe, i.e. a causally closed universe.
2

COSMOLOGY SAFE AS UNIVERSE HAS NO SENSE OF DIRECTION

The universe is expanding uniformly according to research led by UCL which reports that space isn’t stretching in a preferred direction or spinning.

The new study, published today in Physical Review Letters, studied the cosmic microwave background (CMB) which is the remnant radiation from the Big Bang. It shows the universe expands the same way in all directions, supporting the assumptions made in cosmologists’ standard model of the universe.

First author, Daniela Saadeh (UCL Physics & Astronomy), said: “The finding is the best evidence yet that the universe is the same in all directions. Our current understanding of the universe is built on the assumption that it doesn’t prefer one direction over another, but there are actually a huge number of ways that Einstein’s theory of relativity would allow for space to be imbalanced. Universes that spin and stretch are entirely possible, so it’s important that we’ve shown ours is fair to all its directions.”

The team from UCL and Imperial College London used measurements of the CMB taken between 2009 and 2013 by the European Space Agency’s Planck satellite. The spacecraft recently released information about the polarisation of CMB across the whole sky for the first time, providing a complementary view of the early universe that the team was able to exploit.

The researchers modeled a comprehensive variety of spinning and stretching scenarios and how these might manifest in the CMB, including its polarisation. They then compared their findings with the real map of the cosmos from Planck, searching for specific signs in the data.

Daniela Saadeh, explained: “We calculated the different patterns that would be seen in the cosmic microwave background if space has different properties in different directions. Signs might include hot and cold spots from stretching along a particular axis, or even spiral distortions.”

Collaborating author Dr. Stephen Feeney (Imperial College London) added: “We then compare these predictions to reality. This is a serious challenge, as we found an enormous number of ways the universe can be anisotropic. It’s extremely easy to become lost in this myriad of possible universes – we need to tune 32 dials to find the correct one.”

Previous studies only looked at how the universe might rotate, whereas this study is the first to test the widest possible range of geometries of space. Additionally, using the wealth of new data collected from Planck allowed the team to achieve vastly tighter bounds than the previous study. “You can never rule it out completely, but we now calculate the odds that the universe prefers one direction over another at just 1 in 121,000,” said Daniela Saadeh.

Most current cosmological studies assume that the universe behaves identically in every direction. If this assumption were to fail, a large number of analyses of the cosmos and its content would be flawed.

Daniela Saadeh, added: “We’re very glad that our work vindicates what most cosmologists assume. For now, cosmology is safe.”

2

july 22, 2016 | 5:41 pm | (5/100)

my biology test was returned yesterday and i didn’t expect to actually get a good mark, but i did! yaay 🤓  here are my cosmology notes for today’s test 💫🌎🌟☄🌞🌛  one of the few tests i had to think through rather than rely on definitions, facts and other information! i hope u all have a productive weekend!!! 🤗💓

5

ALMA EXPLORES THE HUBBLE ULTRA DEEP FIELD
DEEPEST EVER MILLIMETRE OBSERVATIONS OF EARLY UNIVERSE


International teams of astronomers have used the Atacama Large Millimeter/submillimeter Array (ALMA) to explore the distant corner of the Universe first revealed in the iconic images of the Hubble Ultra Deep Field (HUDF). These new ALMA observations are significantly deeper and sharper than previous surveys at millimetre wavelengths. They clearly show how the rate of star formation in young galaxies is closely related to their total mass in stars. They also trace the previously unknown abundance of star-forming gas at different points in time, providing new insights into the “Golden Age” of galaxy formation approximately 10 billion years ago.

The new ALMA results will be published in a series of papers appearing in the Astrophysical Journal and Monthly Notices of the Royal Astronomical Society. These results are also among those being presented this week at the Half a Decade of ALMA conference in Palm Springs, California, USA.

In 2004 the Hubble Ultra Deep Field images — pioneering deep-field observations with the NASA/ESA Hubble Space Telescope ( http://www.spacetelescope.org) — were published (https://www.spacetelescope.org/images/heic0406a/) . These spectacular pictures probed more deeply than ever before and revealed a menagerie of galaxies stretching back to less than a billion years after the Big Bang. The area was observed several times by Hubble and many other telescopes, resulting in the deepest view (https://www.spacetelescope.org/images/heic1219b/) of the Universe to date.

Astronomers using ALMA have now surveyed this seemingly unremarkable, but heavily studied, window into the distant Universe for the first time both deeply and sharply in the millimetre range of wavelengths [1]. This allows them to see the faint glow from gas clouds and also the emission from warm dust in galaxies in the early Universe.

ALMA has observed the HUDF for a total of around 50 hours up to now. This is the largest amount of ALMA observing time spent on one area of the sky so far.

One team led by Jim Dunlop (University of Edinburgh, United Kingdom) used ALMA to obtain the first deep, homogeneous ALMA image of a region as large as the HUDF. This data allowed them to clearly match up the galaxies that they detected with objects already seen with Hubble and other facilities.

This study showed clearly for the first time that the stellar mass of a galaxy is the best predictor of star formation rate in the high redshift Universe. They detected essentially all of the high-mass galaxies [2] and virtually nothing else.

Jim Dunlop, lead author on the deep imaging paper sums up its importance: “This is a breakthrough result. For the first time we are properly connecting the visible and ultraviolet light view of the distant Universe from Hubble and far-infrared/millimetre views of the Universe from ALMA.”

The second team, led by Manuel Aravena of the Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile, and Fabian Walter of the Max Planck Institute for Astronomy in Heidelberg, Germany, conducted a deeper search across about one sixth of the total HUDF [3].

“We conducted the first fully blind, three-dimensional search for cool gas in the early Universe,” said Chris Carilli, an astronomer with the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, USA and member of the research team. “Through this, we discovered a population of galaxies that is not clearly evident in any other deep surveys of the sky.” [4]

Some of the new ALMA observations were specifically tailored to detect galaxies that are rich in carbon monoxide, indicating regions primed for star formation. Even though these molecular gas reservoirs give rise to the star formation activity in galaxies, they are often very hard to see with Hubble. ALMA can therefore reveal the “missing half” of the galaxy formation and evolution process.

“The new ALMA results imply a rapidly rising gas content in galaxies as we look back further in time,” adds lead author of two of the papers, Manuel Aravena (Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile). “This increasing gas content is likely the root cause for the remarkable increase in star formation rates during the peak epoch of galaxy formation, some 10 billion years ago.”

The results presented today are just the start of a series of future observations to probe the distant Universe with ALMA. For example, a planned 150-hour observing campaign of the HUDF will further illuminate the star-forming potential history of the Universe.

“By supplementing our understanding of this missing star-forming material, the forthcoming ALMA Large Program will complete our view of the galaxies in the iconic Hubble Ultra Deep Field,” concludes Fabian Walter.

###

Notes

[1] Astronomers specifically selected the area of study in the HUDF, a region of space in the faint southern constellation of Fornax - (https://en.wikipedia.org/wiki/Fornax) (The Furnace), so ground-based telescopes in the southern hemisphere, like ALMA, could probe the region, expanding our knowledge about the very distant Universe.

Probing the deep, but optically invisible, Universe was one of the primary science goals for ALMA.

[2] In this context “high mass” means galaxies with stellar masses greater than 20 billion times that of the Sun ( 2 × 10^10 solar masses). For comparison, the Milky Way is a large galaxy and has a mass of around 100 billion solar masses.

[3] This region of sky is about seven hundred times smaller than the area of the disc of the full Moon as seen from Earth. One of the most startling aspects of the HUDF was the vast number of galaxies found in such a tiny fraction of the sky.

[4] ALMA’s ability to see a completely different portion of the electromagnetic spectrum from Hubble allows astronomers to study a different class of astronomical objects, such as massive star-forming clouds, as well as objects that are otherwise too faint to observe in visible light, but visible at millimetre wavelengths.

The search is referred to as “blind” as it was not focussed on any particular object.

The new ALMA observations of the HUDF include two distinct, yet complementary types of data: continuum observations, which reveal dust emission and star formation, and a spectral emission line survey, which looks at the cold molecular gas fueling star formation. The second survey is particularly valuable because it includes information about the degree to which light from distant objects has been redshifted by the expansion of the Universe. Greater redshift means that an object is further away and seen farther back in time. This allows astronomers to create a three-dimensional map of star-forming gas as it evolves over cosmic time.

IMAGE 1….This image combines a background picture taken by the NASA/ESA Hubble Space Telescope (blue/green) with a new very deep ALMA view of this field (orange, marked with circles). All the objects that ALMA sees appear to be massive star-forming galaxies.
This image is based on the ALMA survey by J. Dunlop and colleagues, covering the full HUDF area.
Credit:
ALMA (ESO/NAOJ/NRAO)/NASA/ESA/J. Dunlop et al. and S. Beckwith (STScI) and the HUDF Team.

IMAGE 2….These cutout images are from a combination of a background picture taken by the NASA/ESA Hubble Space Telescope (blue/green) with a new very deep ALMA view of the field (orange, marked with circles). All the objects that ALMA sees appear to be massive star-forming galaxies.
This image is based on the ALMA survey by J. Dunlop and colleagues, covering the full HUDF area.
Credit:
ALMA (ESO/NAOJ/NRAO)/NASA/ESA/J. Dunlop et al. and S. Beckwith (STScI) and the HUDF Team.

IMAGE 3….This image, called the Hubble eXtreme Deep Field (XDF), combines Hubble observations taken over the past decade of a small patch of sky in the constellation of Fornax. With a total of over two million seconds of exposure time, it is the deepest image of the Universe ever made, combining data from previous images including the Hubble Ultra Deep Field (taken in 2003 and 2004) and Hubble Ultra Deep Field Infrared (2009).
The image covers a region less than a tenth of the width of the full Moon across, making it just a 30 millionth of the whole sky. Yet even in this tiny fraction of the sky, the long exposure reveals about 5500 galaxies, some of them so distant that we see them when the Universe was less than 5% of its current age.
The Hubble eXtreme Deep Field image contains several of the most distant objects ever identified.
Credit:
NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team

IMAGE 4….ALMA surveyed the Hubble Ultra Deep Field, uncovering new details of the star-forming history of the Universe. This close-up image reveals one such galaxy (orange), rich in carbon monoxide, showing it is primed for star formation. The blue features are galaxies imaged by Hubble.
This image is based on the very deep ALMA survey by Manuel Aravena, Fabian Walter and colleagues, covering about one sixth of the full HUDF area.
Credit:
B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble

IMAGE 5….A trove of galaxies, rich in carbon monoxide (indicating star-forming potential) were imaged by ALMA (orange) in the Hubble Ultra Deep Field. The blue features are galaxies imaged by Hubble.
This image is based on the very deep ALMA survey by Manuel Aravena, Fabian Walter and colleagues, covering about one sixth of the full HUDF area.
Credit:
B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble

Messier 15 

The globular cluster M 15 lies about 36,000 light-years from Earth in the direction of the constellation Pegasus. It spans nearly 175 light-years across and contains over 100,000 stars as well as a rare planetary nebula, Pease 1, named for its discoverer, the American astronomer Francis Pease. M 15 has one of the densest concentrations of stars within its core region of any cluster in the Milky Way, with an estimated 30.000 stars within an 11 light-year radius of the center. It has been suggested that this severe crowding at the center might be the result of a core collapse due to the mutual gravity of the great number of stars or possibly a black hole.

Credit: David M. Jurasevich

Patterned Beauty of Creation.

Sacred Geometry is the blueprint of Creation and the Genesis of all form. It is an ancient science that explores and explains the Energy Patterns that create and unify all things and reveals the precise way that the Energy of Creation organizes itself. On every scale, every natural pattern of growth or movement conforms inevitably to one or more geometric shapes. As you enter the world of Sacred Geometry you begin to see as never before the wonderfully patterned beauty of Creation.  

The molecules of our DNA, the cornea of our eye, snow flakes, pine cones, flower petals, diamond crystals, the branching of trees, a nautilus shell, the star we spin around, the galaxy we spiral within, the air we breathe, and all life forms as we know them emerge out of timeless Geometric Codes. Viewing and contemplating these codes allow us to gaze directly at the lines on the face of deep Wisdom and offers up a glimpse into the inner workings of the Universal Mind and the Universe itself.

The ancients believed that the experience of Sacred Geometry was essential to the education of the Soul. They knew that these patterns and codes were symbolic of our own inner realm and the subtle structure of Awareness. To them the “Sacred” had particular significance involving Consciousness and the profound mystery of Awareness, the Ultimate Sacred Wonder. Sacred Geometry takes on another whole level of significance when grounded in the experience of Self-Awareness.

sciencealert.com
We just got even weirder results about the 'alien megastructure' star
Something strange is definitely going on.
By Fiona MacDonald

Last year, the world freaked out over the discovery of a star that was dimming and flickering so erratically, it couldn’t be explained by any known natural phenomenon - prompting one scientist to actually go there and suggest it could be evidence of some kind of alien megastructure.

Follow-up studies have revealed no signs of alien behaviour, but NASA’s Kepler Space Telescope has just spent around 1,600 days observing the star, and things have gotten a lot weirder.

“We spent a long time trying to convince ourselves this wasn’t real,” one of the researchers, Ben Montet from Caltetch, told Maddie Stone over at Gizmodo. “We just weren’t able to.”

The results of these latest observations have just gone up on pre-print site arXiv, so other members of the astronomy community can do their best to poke holes in them - which means we can’t read too much into them for now.

But basically what Kepler saw was KIC 8462852, also known as Tabby’s star, dimming at such an incredible rate that it can’t solely be explained by any of the leading hypotheses we had: comet swarms, or the effects of a warped star.

That doesn’t mean we have any more evidence for the alien megastructure hypothesis - the internet-backed idea that an advanced civilisation is building something giant, like a hypothetical Dyson sphere, around the star to harvest its energy.

But what it does suggest is that something’s going on around the star that we’ve never seen anywhere in the cosmos before - most likely a combination of strange phenomena.

Continue Reading.