From DOE’s Lawrence Berkeley National Laboratory(US): “Missing Baryons Found in Far-Out Reaches of Galactic Halos”

From DOE’s Lawrence Berkeley National Laboratory(US)

March 16, 2021
Laurel Kellner
(510) 590-8034

A new study has found that a share of particles that has been challenging to locate is most likely sprinkled across the distant bounds of groups of galaxy halos. The study found some of these particles of baryonic matter are located up to 6 million light-years from their galactic centers. This color-rendered image shows the halo of the Andromeda galaxy, which is the Milky Way’s largest galactic neighbor. (Credit: National Aeronautics and Space Administration(US))

Researchers have channeled the universe’s earliest light – a relic of the universe’s formation known as the cosmic microwave background (CMB) – to solve a missing-matter mystery and learn new things about galaxy formation.

[CMB] per European Space Agency(EU) /Planck.

Their work could also help us to better understand Dark Energy and test Einstein’s theory of general relativity by providing new details about the rate at which galaxies are moving toward us or away from us.

Invisible Dark Matter and dark energy account for about 95% of the universe’s total mass and energy, and the majority of the 5% that is considered ordinary matter is also largely unseen, such as the gases at the outskirts of galaxies that comprise their so-called halos.

Most of this ordinary matter is made up of neutrons and protons – particles called baryons that exist in the nuclei of atoms like hydrogen and helium. Only about 10% of baryonic matter is in the form of stars, and most of the rest inhabits the space between galaxies in strands of hot, spread-out matter known as the warm-hot intergalactic medium, or WHIM.

Because baryons are so spread out in space, it has been difficult for scientists to get a clear picture of their location and density around galaxies. Because of this incomplete picture of where ordinary matter resides, most of the universe’s baryons can be considered as “missing.”

Now, an international team of researchers, with key contributions from physicists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Cornell University(US), has mapped the location of these missing baryons by providing the best measurements, to date, of their location and density around groups of galaxies.

It turns out the baryons are in galaxy halos after all, and that these halos extend much farther than popular models had predicted.

Caterpillar Project A Milky-Way-size dark-matter halo and its subhalos circled, an enormous suite of simulations . Griffen et al. 2016.

While most of an individual galaxy’s stars are typically contained within a region that is about 100,000 light-years from the galaxy’s center, these measurements show that for a given group of galaxies, the most distant baryons can extend about 6 million light-years from their center.

Paradoxically, this missing matter is even more challenging to map out than dark matter, which we can observe indirectly through its gravitational effects on normal matter. Dark matter is the unknown stuff that makes up about 27% of the universe; and dark energy, which is driving matter in the universe apart at an accelerating rate, makes up about 68% of the universe.

“Only a few percent of ordinary matter is in the form of stars. Most of it is in the form of gas that is generally too faint, too diffuse to be able to detect,” said Emmanuel Schaan, Chamberlain Postdoctoral Fellow in Berkeley Lab’s Physics Division and lead author for one of two papers about the missing baryons, published March 15 in the journal Physical Review D.

See also Physical Review D

The researchers made use of a process known as the Sunyaev–Zel’dovich effect that explains how CMB electrons get a boost in energy via a scattering process as they interact with hot gases surrounding galaxy clusters.

“This is a great opportunity to look beyond galaxy positions and at galaxy velocities,” said Simone Ferraro, a Divisional Fellow in Berkeley Lab’s Physics Division who participated in both studies. “Our measurements contain a lot of cosmological information about how fast these galaxies move. It will complement measurements that other observatories make, and make them even more powerful,” he said.

A team of researchers at Cornell University, comprised of research associate Stefania Amodeo, assistant professor. Professor Nicholas Battaglia, and graduate student Emily Moser, led the modeling and the interpretation of the measurements, and explored their consequences for weak gravitational lensing and galaxy formation.

Weak gravitational lensing. NASA/ESA Hubble.

The computer algorithms that the researchers developed should prove useful in analyzing “weak lensing” data from future experiments with high precision. Lensing phenomena occur when massive objects such as galaxies and galaxy clusters are roughly aligned in a particular line of site so that gravitational distortions actually bend and distort the light from the more distant object.

Weak lensing is one of the main techniques that scientists use to understand the origin and evolution of the universe, including the study of dark matter and dark energy. Learning the location and distribution of baryonic matter brings this data within reach.

“These measurements have profound implications for weak lensing, and we expect this technique to be very effective at calibrating future weak-lensing surveys,” Ferraro said.

Schaan noted, “We also get information that’s relevant for galaxy formation.”

In the latest studies, researchers relied on a galaxies dataset from the ground-based Baryon Oscillation Spectroscopic Survey (BOSS) in New Mexico, and CMB data from the Atacama Cosmology Telescope (ACT) in Chile and the European Space Agency’s space-based Planck telescope.

BOSS Supercluster Baryon Oscillation Spectroscopic Survey (BOSS)

Princeton Atacama Cosmology Telescope, on Cerro Toco in the Atacama Desert in the north of Chile, near the Llano de Chajnantor Observatory, Altitude 4,800 m (15,700 ft).

European Space Agency(EU)/Planck 2009 to 2013

Berkeley Lab played a leading role in the BOSS mapping effort, and developed the computational architectures necessary for Planck data-processing at NERSC – National Energy Research Scientific Computing Center.

The algorithms they created benefit from analysis using the Cori supercomputer at Berkeley Lab’s DOE-funded National Energy Research Scientific Computing Center (NERSC). The algorithms counted electrons, allowing them to ignore the chemical composition of the gases.

NERSC Cray Cori II supercomputer at NERSC at LBNL, named after Gerty Cori, the first American woman to win a Nobel Prize in science.

“It’s like a watermark on a bank note,” Schaan explained. “If you put it in front of a backlight then the watermark appears as a shadow. For us the backlight is the cosmic microwave background. It serves to illuminate the gas from behind, so we can see the shadow as the CMB light travels through that gas.”

Ferraro said, “It’s the first really high-significance measurement that really pins down where the gas was.”

The new picture of galaxy halos provided by the “ThumbStack” software that researchers created: massive, fuzzy spherical areas extending far beyond the starlit regions. This software is effective at mapping those halos even for groups of galaxies that have low-mass halos and for those that are moving away from us very quickly (known as “high-redshift” galaxies).

New experiments that should benefit from the halo-mapping tool include the Dark Energy Spectroscopic Instrument, the Vera Rubin Observatory, the Nancy Grace Roman Space Telescope, and the Euclid space telescope.

DOE’s Lawrence Berkeley National Laboratory(US)/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory(US), in the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft).

NOIRLab(US) National Optical Astronomy Observatory(US)/Mayall 4 m telescope at Kitt Peak, Arizona, USA, at Kitt Peak National Observatory(US), in the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft).

NOIRLab(US) Vera C. Rubin Observatory Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes, altitude 2,715 m (8,907 ft).

National Aeronautics and Space Administration(US) Nancy Grace Roman Space Telescope depiction.

See the full article here .


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Bringing Science Solutions to the World

In the world of science, Lawrence Berkeley National Laboratory (Berkeley Lab)(US) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the National Academy of Sciences (NAS), one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California (UC) and is charged with conducting unclassified research across a wide range of scientific disciplines. Located on a 202-acre site in the hills above the UC Berkeley campus that offers spectacular views of the San Francisco Bay, Berkeley Lab employs approximately 3,232 scientists, engineers and support staff. The Lab’s total costs for FY 2014 were $785 million. A recent study estimates the Laboratory’s overall economic impact through direct, indirect and induced spending on the nine counties that make up the San Francisco Bay Area to be nearly $700 million annually. The Lab was also responsible for creating 5,600 jobs locally and 12,000 nationally. The overall economic impact on the national economy is estimated at $1.6 billion a year. Technologies developed at Berkeley Lab have generated billions of dollars in revenues, and thousands of jobs. Savings as a result of Berkeley Lab developments in lighting and windows, and other energy-efficient technologies, have also been in the billions of dollars.

Berkeley Lab was founded in 1931 by Ernest Orlando Lawrence, a UC Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.



The laboratory was founded on August 26, 1931, by Ernest Lawrence, as the Radiation Laboratory of the University of California, Berkeley, associated with the Physics Department. It centered physics research around his new instrument, the cyclotron, a type of particle accelerator for which he was awarded the Nobel Prize in Physics in 1939.

LBNL 88 inch cyclotron.

LBNL 88 inch cyclotron.

Throughout the 1930s, Lawrence pushed to create larger and larger machines for physics research, courting private philanthropists for funding. He was the first to develop a large team to build big projects to make discoveries in basic research. Eventually these machines grew too large to be held on the university grounds, and in 1940 the lab moved to its current site atop the hill above campus. Part of the team put together during this period includes two other young scientists who went on to establish large laboratories; J. Robert Oppenheimer founded DOE’s Los Alamos Laboratory(US), and Robert Wilson founded Fermi National Accelerator Laboratory(US).


Leslie Groves visited Lawrence’s Radiation Laboratory in late 1942 as he was organizing the Manhattan Project, meeting J. Robert Oppenheimer for the first time. Oppenheimer was tasked with organizing the nuclear bomb development effort and founded today’s DOE Los Alamos National Laboratory(US) to help keep the work secret. At the RadLab, Lawrence and his colleagues developed the technique of electromagnetic enrichment of uranium using their experience with cyclotrons. The “calutrons” (named after the University) became the basic unit of the massive Y-12 facility in Oak Ridge, Tennessee. Lawrence’s lab helped contribute to what have been judged to be the three most valuable technology developments of the war (the atomic bomb, proximity fuse, and radar). The cyclotron, whose construction was stalled during the war, was finished in November 1946. The Manhattan Project shut down two months later.


After the war, the Radiation Laboratory became one of the first laboratories to be incorporated into the Atomic Energy Commission (AEC) (now Department of Energy(US). The most highly classified work remained at Los Alamos, but the RadLab remained involved. Edward Teller suggested setting up a second lab similar to Los Alamos to compete with their designs. This led to the creation of an offshoot of the RadLab (now the Lawrence Livermore National Laboratory(US)) in 1952. Some of the RadLab’s work was transferred to the new lab, but some classified research continued at Berkeley Lab until the 1970s, when it became a laboratory dedicated only to unclassified scientific research.

Shortly after the death of Lawrence in August 1958, the UC Radiation Laboratory (both branches) was renamed the Lawrence Radiation Laboratory. The Berkeley location became the Lawrence Berkeley Laboratory in 1971, although many continued to call it the RadLab. Gradually, another shortened form came into common usage, LBNL. Its formal name was amended to Ernest Orlando Lawrence Berkeley National Laboratory in 1995, when “National” was added to the names of all DOE labs. “Ernest Orlando” was later dropped to shorten the name. Today, the lab is commonly referred to as “Berkeley Lab”.

The Alvarez Physics Memos are a set of informal working papers of the large group of physicists, engineers, computer programmers, and technicians led by Luis W. Alvarez from the early 1950s until his death in 1988. Over 1700 memos are available on-line, hosted by the Laboratory.

The lab remains owned by the U.S. Department of Energy, with management from the University of California(US). Companies such as Intel were funding the lab’s research into computing chips.

Science mission

From the 1950s through the present, Berkeley Lab has maintained its status as a major international center for physics research, and has also diversified its research program into almost every realm of scientific investigation. Its mission is to solve the most pressing and profound scientific problems facing humanity, conduct basic research for a secure energy future, understand living systems to improve the environment, health, and energy supply, understand matter and energy in the universe, build and safely operate leading scientific facilities for the nation, and train the next generation of scientists and engineers.

The Laboratory’s 20 scientific divisions are organized within six areas of research: Computing Sciences, Physical Sciences, Earth and Environmental Sciences, Biosciences, Energy Sciences, and Energy Technologies. Berkeley Lab has six main science thrusts: advancing integrated fundamental energy science, integrative biological and environmental system science, advanced computing for science impact, discovering the fundamental properties of matter and energy, accelerators for the future, and developing energy technology innovations for a sustainable future. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab tradition that continues today.

Berkeley Lab operates five major National User Facilities for the DOE Office of Science:

The Advanced Light Source (ALS) is a synchrotron light source with 41 beam lines providing ultraviolet, soft x-ray, and hard x-ray light to scientific experiments.



The ALS is one of the world’s brightest sources of soft x-rays, which are used to characterize the electronic structure of matter and to reveal microscopic structures with elemental and chemical specificity. About 2,500 scientist-users carry out research at ALS every year. Berkeley Lab is proposing an upgrade of ALS which would increase the coherent flux of soft x-rays by two-three orders of magnitude.

The Joint Genome Institute (JGI) supports genomic research in support of the DOE missions in alternative energy, global carbon cycling, and environmental management. The JGI’s partner laboratories are Berkeley Lab, Lawrence Livermore National Lab (LLNL), DOE’s Oak Ridge National Laboratory(US)(ORNL), DOE’s Pacific Northwest National Laboratory(US) (PNNL), and the HudsonAlpha Institute for Biotechnology(US). The JGI’s central role is the development of a diversity of large-scale experimental and computational capabilities to link sequence to biological insights relevant to energy and environmental research. Approximately 1,200 scientist-users take advantage of JGI’s capabilities for their research every year.

The LBNL Molecular Foundry(US) [above] is a multidisciplinary nanoscience research facility. Its seven research facilities focus on Imaging and Manipulation of Nanostructures; Nanofabrication; Theory of Nanostructured Materials; Inorganic Nanostructures; Biological Nanostructures; Organic and Macromolecular Synthesis; and Electron Microscopy. Approximately 700 scientist-users make use of these facilities in their research every year.

The DOE’s NERSC National Energy Research Scientific Computing Center(US) is the scientific computing facility that provides large-scale computing for the DOE’s unclassified research programs. Its current systems provide over 3 billion computational hours annually. NERSC supports 6,000 scientific users from universities, national laboratories, and industry.

National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory

NERSC Cray Cori II supercomputer, named after Gerty Cori, the first American woman to win a Nobel Prize in science.

NERSC Hopper Cray XE6 supercomputer, named after Grace Hopper, One of the first programmers of the Harvard Mark I computer.

NERSC Cray XC30 Edison supercomputer.

NERSC GPFS for Life Sciences.

The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.

NERSC PDSF computer cluster in 2003.

PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.


Cray Shasta Perlmutter SC18 AMD Epyc Nvidia pre-exascale supeercomputer

NERSC is a DOE Office of Science User Facility.

The DOE’s Energy Science Network(US) is a high-speed network infrastructure optimized for very large scientific data flows. ESNet provides connectivity for all major DOE sites and facilities, and the network transports roughly 35 petabytes of traffic each month.

Berkeley Lab is the lead partner in the DOE’s Joint Bioenergy Institute(US) (JBEI), located in Emeryville, California. Other partners are the DOE’s Sandia National Laboratory(US), the University of California (UC) campuses of Berkeley and Davis, the Carnegie Institution for Science(US), and DOE’s Lawrence Livermore National Laboratory(US) (LLNL). JBEI’s primary scientific mission is to advance the development of the next generation of biofuels – liquid fuels derived from the solar energy stored in plant biomass. JBEI is one of three new U.S. Department of Energy (DOE) Bioenergy Research Centers (BRCs).

Berkeley Lab has a major role in two DOE Energy Innovation Hubs. The mission of the Joint Center for Artificial Photosynthesis (JCAP) is to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide. The lead institution for JCAP is the California Institute of Technology(US) and Berkeley Lab is the second institutional center. The mission of the Joint Center for Energy Storage Research (JCESR) is to create next-generation battery technologies that will transform transportation and the electricity grid. DOE’s Argonne National Laboratory(US) leads JCESR and Berkeley Lab is a major partner.

Operations and governance

The University of California(US) operates Lawrence Berkeley National Laboratory under a contract with the US Department of Energy. The site consists of 76 buildings (owned by the U.S. Department of Energy) located on 200 acres (0.81 km^2) owned by the university in the Berkeley Hills. Altogether, the Lab has some 4,000 UC employees, of whom about 800 are students or postdocs, and each year it hosts more than 3,000 participating guest scientists. There are approximately two dozen DOE employees stationed at the laboratory to provide federal oversight of Berkeley Lab’s work for the DOE. Although Berkeley Lab is governed by UC independently of the Berkeley campus, the two entities are closely interconnected: more than 200 Berkeley Lab researchers hold joint appointments as UC Berkeley faculty.
The Lab’s budget for the fiscal year 2019 was US$1.1 billion dollars.

Scientific achievements, inventions, and discoveries

Notable scientific accomplishments at the Lab since World War II include the observation of the antiproton, the discovery of several transuranic elements, and the discovery of the accelerating universe.

Since its inception, 13 researchers associated with Berkeley Lab (Ernest Lawrence, Glenn T. Seaborg, Edwin M. McMillan, Owen Chamberlain, Emilio G. Segrè, Donald A. Glaser, Melvin Calvin, Luis W. Alvarez, Yuan T. Lee, Steven Chu, George F. Smoot, Saul Perlmutter, and Jennifer Doudna) have been awarded either the Nobel Prize in Physics or the Nobel Prize in Chemistry.

In addition, twenty-three Berkeley Lab employees, as contributors to the Intergovernmental Panel on Climate Change, shared the 2007 Nobel Peace Prize with former Vice President Al Gore.

Seventy Berkeley Lab scientists are members of the U.S. National Academy of Sciences(US) (NAS), one of the highest honors for a scientist in the United States. Thirteen Berkeley Lab scientists have won the National Medal of Science, the nation’s highest award for lifetime achievement in fields of scientific research. Eighteen Berkeley Lab engineers have been elected to the National Academy of Engineering, and three Berkeley Lab scientists have been elected into the National Academy of Medicine. Nature Index rates the Lab sixth in the world among government research organizations; it is the only one of the top six that is a single laboratory, rather than a system of laboratories.

Elements discovered by Berkeley Lab physicists include astatine, neptunium, plutonium, curium, americium, berkelium*, californium*, einsteinium, fermium, mendelevium, nobelium, lawrencium*, dubnium, and seaborgium*. Those elements listed with asterisks (*) are named after the University Professors Lawrence and Seaborg. Seaborg was the principal scientist involved in their discovery. The element technetium was discovered after Ernest Lawrence gave Emilio Segrè a molybdenum strip from the Berkeley Lab cyclotron. The fabricated evidence used to claim the creation of oganesson and livermorium by Victor Ninov, a researcher employed at Berkeley Lab, led to the retraction of two articles.

Inventions and discoveries to come out of Berkeley Lab include: “smart” windows with embedded electrodes that enable window glass to respond to changes in sunlight, synthetic genes for antimalaria and anti-AIDS superdrugs based on breakthroughs in synthetic biology, electronic ballasts for more efficient lighting, Home Energy Saver, the web’s first do-it-yourself home energy audit tool, a pocket-sized DNA sampler called the PhyloChip, and the Berkeley Darfur Stove, which uses one-quarter as much firewood as traditional cook stoves. One of Berkeley Lab’s most notable breakthroughs is the discovery of Dark Energy. During the 1980s and 1990s Berkeley Lab physicists and astronomers formed the Supernova Cosmology Project (SCP), using Type Ia supernovae as “standard candles” to measure the expansion rate of the universe. Their successful methods inspired competition, with the result that early in 1998 both the SCP and the Harvard Cosmology with Supernovae: The High-Z Supernova Search High-Z SN(US) announced the surprising discovery that expansion is accelerating; the cause was soon named Dark Energy.

Arthur Rosenfeld, a senior scientist at Berkeley Lab, was the nation’s leading advocate for energy efficiency from 1975 until his death in 2017. He led efforts at the Lab that produced several technologies that radically improved efficiency: compact fluorescent lamps, low-energy refrigerators, and windows that trap heat. He established the Center for Building Science at the Lab, which developed into the Building Technology and Urban Systems Division. He developed the first energy-efficiency standards for buildings and appliances in California, which helped the state to sustain constant electricity use per capita, a phenomenon called the Rosenfeld effect. The Energy Efficiency and Environmental Impacts Division continues to set the research foundation for the national energy efficiency standards and works with China, India, and other countries to help develop their standards.

Carl Haber and Vitaliy Fadeyev of Berkeley Lab developed the IRENE system for optical scanning of audio discs and cylinders.
In December 2018, researchers at Intel Corp. and the Lawrence Berkeley National Laboratory published a paper in Nature, which outlined a chip “made with quantum materials called magnetoelectric multiferroics instead of the conventional silicon,” to allow for increased processing and reduced energy consumption to support technology such as artificial intelligence.

A U.S. Department of Energy National Laboratory Operated by the University of California.

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