Cosmology Archives

February 10, 2013December 23, 2015 by Tammy Plotner

Messier 106: Amateur and Professional Astronomers Join Together to Peer Into the Eyes of Creation

Traveling to distant galaxies may have interesting consequences. Credit: Hubble Release, Messier 106

Nearly four million light years away in the direction of the constellation of Canes Venatici, a visage of creation awaited to be revealed. Now, thanks to the teamwork of the astronomical image processors at the Space Telescope Science Institute in Baltimore, Maryland, and world-renowned astrophotographers Robert Gendler and Jay GaBany, we’re able to see combined Hubble Space Telescope data with ground-based telescope imaging. Let’s look deep into spiral galaxy, Messier 106.

This wasn’t an overnight imaging project. “A few months ago the Hubble Heritage Team contacted me and asked if I’d be interested in making a large format image of M106 from the available data on the Hubble Legacy Archive,” says Gendler. “I agreed and went to work downloading a large number of data sets from the HLA. I realized this would be a massive project. The image would be a mosaic of more than 30 panels and would incorporate both wideband and narrowband data sets.”

With the cooperation of Jay GaBany, they combined their own observations/images of this magnificent structure and compiled it with Hubble data – filling in areas where no data was available. The resulting image is a portrait of such depth and beauty that it’s almost like looking into the eyes of creation itself.

Be swept away…

If you’re drawn to the core of Messier 106, there’s good reason. It isn’t just an ordinary spiral galaxy, it’s one that has a peculiar jet flow which can be detected in radio and in H-alpha wavelengths. “Due to the special geometry of the galaxy, the jets emerge from the nuclear region through the galactic disk,” says Marita Krause (et al). “Also the distribution of molecular gas looks different from that in other spiral galaxies.” It is just this difference that makes NGC 4258 (M106) stand out a bit from the crowd and so worthy of further processing. According to new modeling techniques the “concentration of CO along the ridges is due to interaction of the rotating gas clouds with the jet’s magnetic field by ambipolar diffusion. This magnetic interaction is thought to increase the time the molecular clouds reside near the jet thus leading to the quasi-static CO ridge.”

Knowing those jets are present and the hunger to reveal them through imaging became the driving force for R. Jay GaBany. “Since the early 1960s, M106, also known as NGC 4258, has been known to exhibit an extra pair of arms, located between the spiral arms comprised of stars, dust and gas. But an explanation for their existence remained elusive until earlier in this decade,” says Jay. “My contribution to the image came from my 2010 image of M-106 that revealed the full extent of its amazing jets. My image include 22 hours of white light exposures through clear, red, blue and green filters plus and other 15 hours of imaging through a 6nm narrow band h-alpha filter.”

“Seen in the light emitted by hydrogen molecules when they become ionized, these arms display an artificial red hue to make them visible in the image I produced. The extra arms are now believed to be caused by high energy jets emanating from an active 40 million solar mass super-massive black hole menacing the galaxy’s center,” explains GaBany. “Because the jets are tilted at a low inclination they pierce the disk and surrounding halo of this galaxy. So, as the jets pass through regions of gas, they create an expanding cocoon of shock waves that heats the surrounding material causing it to release radiation in optical wavelengths. The curvature and fraying seen at their extremities represents previous trajectories of the jet due to past precession. Precession is a change in the orientation of the rotation axis of a spinning object. For example, the wobble of a spinning top.”

Yet, that’s not all. This low luminosity Seyfert II galaxy is also hosting a maser – its warped disk of water molecules discovered in 1994. Through radio observations, M106 became the first of its kind to show the exact location of the core of an AGN (active galactic nucleus). According to a study done by JR Herrnstein (et al): “NGC 4258 is an exceptional laboratory for the study of AGN accretion processes. The nuclear maser reveals details about the kinematics and structure of the accretion disk on subparsec scales and permits the determination of the central mass with great precision.”

And there is still more…

Deep inside lurks that known supermassive black hole – one that’s extremely active and produces bright microwave radiation. But, don’t stop there. Ordinarily a spiral galaxy has two arms, but M106 has double. These ethereal “extras” can be seen as faint ribbons of gas at optical wavelengths, but become solidified when viewed in x-ray and radio. Here the structure is formed in hot gas rather than stars. While this process was once a mystery to astronomers, new information suggests they may arise from the black hole activity, making them a unique artifact. What could cause it? These “extra arms” could be the result of the violent turbulence at the core – where gases are superheated and interact with their denser counterparts causing them to illuminate. At the perimeter of the galactic structure, the gases are more loose and the arching formation could be the product of the movement of jet activity.

“One goal I had early on was to feature the well known ‘anomalous arms’ of M106,” said Gendler. “This feature, peculiar to M106, is thought to arise from superheated gases, energized by accretion of matter into the galaxy’s massive black hole. The anomalous arms emit light in the visual spectrum around 656nm (hydrogen alpha) and I found a fair amount of hydrogen alpha data sets for the arms in the HLA.”

Gendler was responsible for all the image assembly and processing. “Assembling the image required over two months,” he said. “The quality of the data ranged from good to very poor. The central galaxy had sufficient color data but away from the center the Hubble data was incomplete and in some areas did not exist. I then decided to use ground based data from my own image and Jay GaBany’s image of M106 to fill in areas of missing or incomplete Hubble data. I also used ground based data to boost the signal of the outer areas of the galaxy as the Hubble data was sparse and of short exposure for the more remote areas of the galaxy.”

All in all, Messier 106 is a galaxy that deserves attention – attention and a loving touch given by two of the very best amateur astronomers and dedicated astrophotographers to be found.

Original News Source: HubbleSite Image Release.

February 5, 2013December 23, 2015 by John Williams

Super Good at Collecting Data, Massive Science Balloon Breaks Records

Super-TIGER prepares for launch from Antarctica.

NASA’s Super-TIGER science balloon landed Friday at a frigid and remote base in Antarctica after setting two duration records while gathering data about cosmic rays. There’s so much data that it will take scientists about two years to analyze, according to NASA.

Launched December 8, 2012 from the Long Duration Balloon site near McMurdo Station in Antarctica, the Super Trans-Iron Galactic Element Recorder balloon spent 55 days, 1 hour and 34 minutes aloft, shattering records previously set in 2009 by another NASA balloon for longest flight by a balloon of its size. The 39-million cubic foot balloon, spent most of its time cruising four times higher than commercial airlines at about 127,000 feet (almost 39 kilometers). The instrument is managed by Washington University in St. Louis, Missouri.

“Scientific balloons give scientists the ability to gather critical science data for a long duration at a very low relative cost,” said Vernon Jones, NASA’s Balloon Program scientist, in the press release. “Super-TIGER is scientific ballooning at its best.”

Super-TIGER measured rare heavy elements, such as iron, as they bombarded Earth from the Milky Way. The instrument detected about 50 million of these high-energy cosmic rays. Scientists hope the data from the mission will help understand where the energetic nuclei are produced and how they achieve such high energies.

NASA had three long-duration balloon missions in the summer skies of Antarctica. SuperTIGER was joined by BLAST and EBEX. All three balloons launched from the site near McMurdo Station in December. BLAST, or Balloon Borne Large Aperture Submillimeter Telescope launched Christmas Day and measured the polarized dust in star-forming regions helping astronomers determine if magnetic fields are a dominant force over turbulence in star-forming regions of the galaxy. BLAST’s mission lasted just over 16 days.

EBEX, the heaviest scientific payload borne aloft by a NASA balloon, measures cosmic microwave background radiation. The mission lasted 25 days and reached altitudes of 118,000 feet (or 36 kilometers).

Antarctica, it turns out, is ideal for these types of long-duration balloon missions with sparse populations and anticyclonic (east to west, counter-clockwise in the southern hemisphere) wind patterns in the stratosphere.

Source: NASA

January 31, 2013December 23, 2015 by Evan Gough

Book Review: Unraveling the Universe’s Mysteries

“Unraveling the Universe’s Mysteries” is Louis A. Del Monte’s contribution to the world of science writing. If you haven’t heard of him, don’t be surprised. He’s not a prolific author or researcher, but worked in the development of microelectronics for the US companies IBM and Honeywell before forming a high-tech e-marketing agency.

The book lives up to its title and long subtitle: “Explore sciences’ most baffling mysteries, including the Big Bang’s origin, time travel, dark energy, humankind’s fate, and more.” It covers string theory, the Big Bang, dark matter, dark energy, time travel, the existence of God, and other mysterious aspects of our Universe. Del Monte also discusses artificial intelligence, the end of the Universe, and the mysterious nature of light. These subjects have all been covered in great detail by other authors in other books. How does Del Monte’s treatment of these subjects stand up in comparison?

Not great, in my opinion. The writing is somehow uninviting. The book reads more like a textbook or a lecture than it does a science book for an interested audience. It’s somewhat dry, and the writing is kind of heavy. After looking into Del Monte’s background, it becomes clear why. He’s an engineer, and his background is in writing technical papers.

This book is a bit of a puzzle, as is the author himself. I’ve mentioned the problems with the writing, but there are other issues. In one instance Del Monte references a study from the Journal of Cosmology. If you haven’t heard of that journal, it’s come under heavy criticism for its peer-review process, and isn’t highly regarded in science circles. The Journal of Cosmology seems to be a journal for people with an axe to grind around certain issues more than a healthy part of the science journal community. To be quoting studies from it is a bit of a black mark, in my opinion.

In another instance, he opens the chapter on Advanced Aliens with a quote from “Chariot of the Gods”, that old book/documentary from the 1970’s that just won’t seem to die, no matter how discredited it is. The main thrust of “Chariot of the Gods” is that human civilisation got a technological boost from visitations by advanced aliens. Readers can judge for themselves the wisdom of quoting “Chariot of the Gods” in a science book.

The publisher bills the book as “a new theory to explain one of cosmology’s most profound mysteries, the accelerated expansion of the universe,” and that Del Monte “presents an original solution to Einstein’s equations of special relativity.” But without conducting peer reviewed research, the validity of his theory comes into question.

If I seem puzzled by this book, it’s because I am. Del Monte seems to be a bit of an outsider when it comes to writing about astronomy and cosmology. He has no background in it. There’s nothing wrong with that in principle; there’s always room for new perspectives in science. But I can’t help thinking that he could’ve benefited from working more closely with an experienced editor.

Readers will get something out of this book; it’s an interesting discussion of the mysterious aspects of our Universe. But it’s also a somewhat strange book. For those of you who decide to read it, you’re in for an interesting read.

For more information about Louis Del Monte, see his website.

January 3, 2013December 23, 2015 by Jason Major

The Face of Creation

The latest autotuned installment in John D. Boswell’s Symphony of Science series waxes melodic about the particle-smashing science being done with the Large Hadron Collider at CERN, in particular its search for the Higgs boson, a.k.a. the… ok, ok, I won’t say it…

“We can recreate the conditions that were present just after the beginning of the Universe.”
– Prof. Brian Cox, “The Face of Creation”

John has been entertaining science fans with his Symphony mixes since 2009, when his first video in the series — “A Glorious Dawn” featuring Carl Sagan — was released. Now John’s videos are eagerly anticipated by fans, who follow him on YouTube and on Twitter as @melodysheep.

I’d have to say my all-time favorite is “Onward to the Edge”, featuring astrophysicist Neil deGrasse Tyson, Professor Brian Cox and Carolyn Porco from the Cassini imaging team.

Thanks to some help from Kickstarter, John has recently released an original album, Terra Lumina, a “collection of folk/rock songs with themes including gravity, geology, photons, and the Doppler effect.” It’s a unique musical take on some of science’s most amazing discoveries, from John D. Boswell and vocalist William Crowley. Check out the video trailer here.

The album can be found on Amazon and on iTunes.

Videos via melodysheep

January 1, 2013December 23, 2015 by Jason Major

New Study Shows Cosmic Rays Could Cause Alzheimer’s

Humans explore Mars in “Distant Shores,” an illustration by NASA artist Pat Rawlins

Cosmic rays from deep space could pose serious health risks to future astronauts on long-duration missions to Mars — even bringing on the memory-destroying symptoms of Alzheimer’s disease, according to the results of a new study from the University of Rochester Medical Center.

While NASA has its sights set on the human exploration of Mars within the next several decades, even with the best propulsion technology currently available such a mission would take about three years. Within that time, crew members would be constantly exposed to large amounts of radiation that we are protected from here by Earth’s magnetic field and atmosphere. Some of this radiation comes in the form of protons from the Sun and can be blocked by adequate spacecraft shielding materials, but a much bigger danger comes from heavy high-energy particles that are constantly whipping across the galaxy, shot out of the hearts of exploding giant stars.

“Because iron particles pack a bigger wallop it is extremely difficult from an engineering perspective to effectively shield against them. One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete.”

– M. Kerry O’Banion, M.D., Ph.D.

While health risks from these high-mass, high-charged (HZE) particles have long been known, the exact nature of the damages they can cause to human physiology is still being researched — even more so now that Mars and asteroid exploration is on NASA’s short list.

Now, a team from the University of Rochester Medical Center (URMC) in New York has announced the results of their research linking high-energy radiation — just like what would be encountered during a trip to Mars — to the degeneration of brain function, and possibly even the onset of Alzheimer’s disease.

“Galactic cosmic radiation poses a significant threat to future astronauts,” said M. Kerry O’Banion, M.D., Ph.D., a professor in the University of Rochester Medical Center (URMC) Department of Neurobiology and Anatomy and the senior author of the study. “The possibility that radiation exposure in space may give rise to health problems such as cancer has long been recognized. However, this study shows for the first time that exposure to radiation levels equivalent to a mission to Mars could produce cognitive problems and speed up changes in the brain that are associated with Alzheimer’s disease.”

In particular the team focused on iron ions, which are blasted into space by supernovae and are massive enough to punch through a spacecraft’s protective shielding.

“Because iron particles pack a bigger wallop it is extremely difficult from an engineering perspective to effectively shield against them,” O’Banion said. “One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete.”

By exposing lab mice to increasing levels of radiation and measuring their cognitive ability the researchers were able to determine the neurologically destructive nature of high-energy particles, which caused the animals to more readily fail cognitive tasks. In addition the exposed mice developed accumulations of a protein plaque within their brains, beta amyloid, the spread of which is associated with Alzheimer’s disease in humans.

“These findings clearly suggest that exposure to radiation in space has the potential to accelerate the development of Alzheimer’s disease,” said O’Banion. “This is yet another factor that NASA, which is clearly concerned about the health risks to its astronauts, will need to take into account as it plans future missions.”

While Mars explorers could potentially protect themselves from cosmic radiation by setting up bases in caves, empty lava tubes or beneath rocky ledges, which would offer the sort of physical shielding necessary to stop dangerous HZE particles, that would obviously present a new set of challenges to astronauts working in an already alien environment. And there’s always the trip there (and back again) during which time a crew would be very much exposed.

While this won’t — and shouldn’t — prevent a Mars mission from eventually taking place, it does add yet another element of danger that will need to be factored in and either dealt with from both health and engineering standpoints… or accepted as an unavoidable risk by all involved, including the public.

How much risk will be considered acceptable for the human exploration of Mars — and beyond? (NASA/Pat Rawlings)

Read more on the URMC news page here, and see the full experiment report here.

Illustrations for NASA by Pat Rawlings. See more of Rawling’s artwork here. Inset image: comparison of human brains without and with Alzheimer’s. Source: WHYY.

December 12, 2012December 23, 2015 by Astronomy Cast

Podcast: Cosmological Constant

In order to allow for a static Universe, Albert Einstein introduced the concept of the Cosmological Constant Lambda to make the math work out. Once it was discovered that the Universe was actually expanding, he threw the number out calling it his “biggest blunder.” But thanks to dark energy, the Cosmological Constant is back.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Cosmological Constant” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:

December 11, 2012December 23, 2015 by Nancy Atkinson

Stephen Hawking and CERN LHC Team Each Win $3 Million Prize

Stephen Hawking visited the Large Hadron Collider’s underground tunnel at Europe’s CERN particle physics research center in 2006. Hawking and seven CERN researchers receiving multimillion-dollar prizes from the Fundamental Physics Prize Foundation. Image credit: CERN

Two $3,000,000 special physics prizes have been awarded to Stephen Hawking and to seven scientists who led the effort to discover a Higgs-like particle at CERN’s Large Hadron Collider. The Fundamental Physics Prize Foundation, backed by Russian billionaire Yuri Milner announced the awards today, saying that Hawking is honored for his discovery of Hawking radiation from black holes “and his deep contributions to quantum gravity and quantum aspects of the early universe,” and that the prize money for the European Organization for Nuclear Research, or CERN, is being shared among a scientist who administered the building of the $10 billion Large Hadron Collider and six physicists who directed two teams of 3,000 scientists each.

The $3 million Fundamental Physics Prize is awarded annually by the nonprofit Fundamental Physics Prize Foundation to recognize “transformative advances in the field.” The $3 million prize may also be given at any time outside the formal nomination process “in exceptional cases,” according to the Foundation. When the Foundation’s prize intentions were announced in July of this year, Milner said, “I hope the new prize will bring long overdue recognition to the greatest minds working in the field of fundamental physics, and if this helps encourage young people to be inspired by science, I will be deeply gratified.”

The Foundation said the seven were being honored “for their leadership role in the scientific endeavor that led to the discovery of the new Higgs-like particle by the ATLAS and CMS collaborations at CERN’s Large Hadron Collider.” They will share the $3 million prize equally.

The laureates include Lyn Evans, a Welsh scientist who serves as the LHC’s project leader; Peter Jenni amd Fabiola Gianotti of the LHC’s ATLAS collaboration; and Michel Della Negra, Tejinder Singh Virdee, Guido Tonelli and Joe Incandela of the CMS collaboration.

“It is a great honour for the LHC’s achievement to be recognised in this way,” said CERN Director General Rolf Heuer in a statement. “This prize recognizes the work of everyone who has contributed to the project over many years. The Fundamental Physics Prize underlines the value of fundamental physics to society, and I am delighted that the Foundation has chosen to hold its first award ceremony at CERN.”

“I am very much pleased with the decisions of the Selection Committee,” commented Yuri Milner. “I hope that the prizes will bring further recognition to some of the most brilliant minds in the world and the great accomplishments they have produced.”

“Choosing this year’s recipients from such a large pool of spectacular nominations was a very difficult task,” said Nima Arkani-Hamed, a member of the Selection Committee. “The selected physicists have done transformative work spanning a wide range of areas in fundamental physics. I especially look forward to future breakthroughs from the first recipients of the New Horizons in Physics Prize.”

The laureates of 2013 New Horizons in Physics Prize are:

Niklas Beisert for the development of powerful exact methods to describe a quantum gauge theory and its associated string theory;

Davide Gaiotto for far-reaching new insights about duality, gauge theory, and geometry, and especially for his work linking theories in different dimensions in most unexpected ways;

Zohar Komargodski for his work on the dynamics of four-dimensional field theories. In particular, his proof of the “a-theorem” has solved a long-standing problem, leading to deep new insights.

Each of the laureates will receive $100,000.

Sources: Fundamental Physics Prize Foundation, IOP, CERN

December 7, 2012April 26, 2016 by Jason Major

Do We Really Need Dark Matter?

Hubble mosaic of massive galaxy cluster MACS J0717.5+3745, thought to be connected by a filament of dark matter. Credit: NASA, ESA, Harald Ebeling (University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

Even though teams of scientists around the world are at this very moment hot on the trail of dark matter — the “other stuff” that the Universe is made of and supposedly accounts for nearly 80% of the mass that we can’t directly observe (yet) — and trying to quantify exactly how so-called “dark energy” drives its ever-accelerating expansion, perhaps one answer to these ongoing mysteries is maybe they don’t exist at all.

This is precisely what one astronomer is suggesting in a recent paper, submitted Dec. 3 to Astrophysical Journal Letters.

In a paper titled “An expanding universe without dark matter and dark energy” (arXiv:1212.1110) Pierre Magain, a professor at Belgium’s Institut d’Astrophysique et de Géophysique, proposes that the expansion of the Universe could be explained without the need for enigmatic material and energy that, to date, has yet to be directly measured.

In addition, Magain’s proposal puts a higher age to the Universe than what’s currently accepted. With a model that shows a slower expansion rate during the early Universe than today, Magain’s calculations estimate its age to be closer to 15.4 – 16.5 billion years old, adding a couple billion more candles to the cosmic birthday cake.

The benefit to a slightly older Universe, Magain posits, is that it’s not so uncannily close to the apparent age of the most distant galaxies recently found — such as MACS0647-JD, which is 13.3 billion light-years away and thus (based on current estimates, see graphic at right) must have formed when the Universe was a mere 420 million years old.

Using accepted physics of how time behaves based on Einstein’s theory of general relativity — namely, how the passage of time is relative to the position and velocity of the viewer (as well as the intensity of the gravitational field the viewer is within) — Magain’s model allows for an observer located within the Universe to potentially be experiencing a different rate of time than a hypothetical viewer located outside the Universe. Not to be so metaphysical as to presume that there are external observers of our Universe but merely to say that an external point would be a fixed one against which one could benchmark a varying passage of time inside the Universe, Magain calls this universal relativity.

A viewer experiencing universal relativity would, Magain claims, always measure the curvature of the Universe to be equal to zero. This is what’s currently observed, a “flatness problem” that Magain insinuates is strangely coincidental.

By attributing an expanding Universe to dark energy and the high velocities of stars along the edges of galaxies (as well as the motions of galaxy clusters themselves) to dark matter, we may be introducing ad hoc elements to the Universe, says Magain. Instead, he proposes his “more economical” model — which uses universal relativity — explains these apparently accelerating, increasingly expanding behaviors… and gives a bigger margin of time between the Big Bang and the formation of the first galactic structures.

There’s quite a bit of math involved, and since I never claimed to understand physics equations you can check out the original paper here.

While intriguing, the bottom line is that dark energy and dark matter have still managed to elude science, existing just outside the borders of what can be observed (although the gravitational lensing effects of what’s thought to be dark matter filaments have been observed by Hubble) and Magain’s paper is merely putting another idea onto the table — one that, while he recognizes needs further testing and relies upon very specific singular parameters, doesn’t depend upon invisible, unobservable and mysteriously dark “stuff”. Whether it belongs on the table or not will be up to other astrophysicists to decide.

Prof. Magain’s research was supported by ESA and the Belgian Science Policy Office.

At right: Artist’s impression of dark matter (h/t to Steve Nerlich)

Note: this is “just” a submitted paper and has not been selected for publication yet. Any hypotheses proposed are those of the author and are not endorsed by this site. (Personally I like dark matter. It’s fascinating stuff… even if we can’t see it. Want an astrophysicist’s viewpoint on the existence of dark matter? Check out Ethan Siegel’s blog response here.)

December 5, 2012October 24, 2018 by Jason Major

Pale Blue Dot: an Animated Contemplation

Every now and then, someone takes Carl Sagan’s wonderful reading of his iconic “Pale Blue Dot” narrative and turns it into an animated presentation, usually combining images and video footage of space exploration and Earthly vistas to create something undeniably spellbinding (Sagan’s narratives do have a tendency to have that effect!) Artist Adam Winnik went a slightly different route, however, creating an illustrated animation to go along with Sagan’s reading for his thesis project in 2011. The result is no less poignant… check it out above.

See more of Adam’s work on his website here.

Video: Adam Winnik. Music: Hans Zimmer “You’re So Cool”

December 4, 2012December 23, 2015 by Jason Major

The Brightest Galaxies in the Universe Were Invisible… Until Now

Hubble images of six of the starburst galaxies first found by ESA’s Herschel Space Observatory (Keck data shown below each in blue)

Many of the brightest, most actively star-forming galaxies in the Universe were actually undetectable by Earth-based observatories, hidden from view by thick clouds of opaque dust and gas. Thanks to ESA’s Herschel space observatory, which views the Universe in infrared, an enormous amount of these “starburst” galaxies have recently been uncovered, allowing astronomers to measure their distances with the twin telescopes of Hawaii’s W.M. Keck Observatory. What they found is quite surprising: at least 767 previously unknown galaxies, many of them generating new stars at incredible rates.

Although nearly invisible at optical wavelengths these newly-found galaxies shine brightly in far-infrared, making them visible to Herschel, which can peer through even the densest dust clouds. Once astronomers knew where the galaxies are located, they were able to target them with Hubble and, most importantly, the two 10-meter Keck telescopes — the two largest optical telescopes in the world.

By gathering literally hundreds of hours of spectral data on the galaxies with the Keck telescopes, estimates of their distances could be determined as well as their temperatures and how often new stars are born within them.

“While some of the galaxies are nearby, most are very distant; we even found galaxies that are so far that their light has taken 12 billion years to travel here, so we are seeing them when the Universe was only a ninth of its current age,” said Dr. Caitlin Casey, Hubble fellow at the UH Manoa Institute for Astronomy and lead scientist on the survey. “Now that we have a pretty good idea of how important this type of galaxy is in forming huge numbers of stars in the Universe, the next step is to figure out why and how they formed.”

A representation of the distribution of nearly 300 starbursts in one 1.4 x 1.4 degree field of view.

The galaxies, many of them observed as they were during the early stages of their formation, are producing new stars at a rate of 100 to 500 a year — with a mass equivalent of several thousand Suns — hence the moniker “starburst” galaxy. By comparison the Milky Way galaxy only births one or two Sun-mass stars per year.

The reason behind this explosion of star formation in these galaxies is unknown, but it’s thought that collisions between young galaxies may be the cause.

Another possibility is that galaxies had much more gas and dust during the early Universe, allowing for much higher star formation rates than what’s seen today.

“It’s a hotly debated topic that requires details on the shape and rotation of the galaxies before it can be resolved,” said Dr. Casey.

Still, the discovery of these “hidden” galaxies is a major step forward in understanding the evolution of star formation in the Universe.

“Our study confirms the importance of starburst galaxies in the cosmic history of star formation. Models that try to reproduce the formation and evolution of galaxies will have to take these results into account.”

– Dr. Caitlin Casey, Hubble fellow at the UH Manoa Institute for Astronomy

“For the first time, we have been able to measure distances, star formation rates, and temperatures for a brand new set of 767 previously unidentified galaxies,” said Dr. Scott Chapman, a co-author on the studies. “The previous similar survey of distant infrared starbursts only covered 73 galaxies. This is a huge improvement.”

The papers detailing the results were published today online in the Astrophysical Journal.

Sources: W.M. Keck Observatory article and ESA’s news release.

Image credits: ESA–C. Carreau/C. Casey (University of Hawai’i); COSMOS field: ESA/Herschel/SPIRE/HerMES Key Programme; Hubble images: NASA, ESA. Inset image courtesy W. M. Keck Observatory.