Carl William Akerlof (born March 5, 1938) is an American particle physicist and astrophysicist. A professor of physics at the University of Michigan, Akerlof initiated and led the Robotic Optical Transient Search Experiment (ROTSE), [1] a ground-breaking effort to find fast astrophysical optical transients, particularly gamma-ray bursts. Akerlof has co-authored over 400 papers with 1500 collaborators, which have been cited over 6000 times. [2] He was elected in 1993 a fellow of the American Physical Society (APS).
Akerlof was born in New Haven, Connecticut, on March 5, 1938, [3] into a Jewish family. His mother was Rosalie Clara Grubber (née Hirschfelder), a housewife of German Jewish descent, and his father was Gösta Carl Åkerlöf, a chemist and inventor, who was a Swedish immigrant. Both his father and his uncle were physical chemists who worked on the Manhattan Project during World War II. [4] His brother, George, is a 2001 Nobel Memorial Prize in Economic Sciences laureate. [5]
Akerlof earned his bachelor's in physics from Yale University in 1960, and earned his PhD from Cornell University 1967. He joined the faculty of the University of Michigan in 1969, where he has remained ever since. [3]
Akerlof initially studied the strong and electromagnetic interactions of elementary particles in a number of experiments at the Cornell electron synchrotron, Argonne National Laboratory, Fermilab and the Stanford Linear Accelerator. His interests began to shift to astrophysics in 1980 with the exploration of how high energy particle physics techniques could be applied to astrophysics. The first effort along these lines showed that despite the wishful thinking of a number of physicists, magnetic monopoles could not be detected by the acoustic waves that would be generated in electrical conductors. [6] In 1986, he started to look for TeV gamma-ray radiation of cosmic origin using a pair of solar concentrators at Sandia National Laboratory as light collectors. [7] This work morphed into collaboration with a group at Mt. Hopkins, Arizona directed by Trevor Weekes that led to the unexpected discovery of such radiation from Active Galactic Nuclei at cosmological distances. A few years later, fascinated by the mystery of bright cosmic explosions called gamma-ray bursts, he began a series of experiments in 1992 to find prompt optical traces of these violent events, culminating in a successful optical observation on January 23, 1999. [8]
Akerlof has worked to foster international collaboration, including a 1974 sabbatical in the Soviet Union to work on an experiment at the 70 GeV particle accelerator at Serpukov. [4] The trip produced little science but provided significant insights regarding the organizational difficulties faced by Russian physicists in the waning decade of the Soviet system. [9]
With the goal of encouraging other nations to find effective paths to interesting and affordable astrophysics research, he has visited a number of countries including China, Iran, South Africa and Thailand. His most significant contribution in this area is the ROTSE Collaboration which has built and operated four robotic optical telescopes on four continents in Australia, the United States, Namibia and Turkey. This project has been running for about a decade and has successfully observed and detected gamma-ray bursts and supernovae. A former University of Michigan student, Wiphu Rujopakorn, has taken advantage of the ROTSE imaging data for instructing school children in Thailand about the mysteries of astronomy. [1]
Akerlof is best known for his work in establishing the feasibility of real time searches for optical transients and the subsequent observations of a large number of gamma-ray bursts and supernovae. He was also a participant in the discovery of TeV gamma-rays from the type of Active Galactic Nuclei known as “blazars”. NASA considered his discovery of optical radiation from GRB990123 [10] one of the top ten discoveries of that year. [11] His earlier work in particle physics has been widely cited. [2] Most recently, his teaching activities have led him to introduce a number of astrophysics experiments into the undergraduate lab curriculum.
Cosmic rays or astroparticles are high-energy particles or clusters of particles that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's atmosphere, cosmic rays produce showers of secondary particles, some of which reach the surface, although the bulk are deflected off into space by the magnetosphere or the heliosphere.
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies, described by NASA as "the most powerful class of explosions in the universe". They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milliseconds to several hours. After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths.
A magnetar is a type of neutron star with an extremely powerful magnetic field (~109 to 1011 T, ~1013 to 1015 G). The magnetic-field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays.
The Fermi Gamma-ray Space Telescope, formerly called the Gamma-ray Large Area Space Telescope (GLAST), is a space observatory being used to perform gamma-ray astronomy observations from low Earth orbit. Its main instrument is the Large Area Telescope (LAT), with which astronomers mostly intend to perform an all-sky survey studying astrophysical and cosmological phenomena such as active galactic nuclei, pulsars, other high-energy sources and dark matter. Another instrument aboard Fermi, the Gamma-ray Burst Monitor, is being used to study gamma-ray bursts and solar flares.
The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with energies from 20 keV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main telescopes in one spacecraft, covering X-rays and gamma rays, including various specialized sub-instruments and detectors. Following 14 years of effort, the observatory was launched from Space Shuttle Atlantis during STS-37 on April 5, 1991, and operated until its deorbit on June 4, 2000. It was deployed in low Earth orbit at 450 km (280 mi) to avoid the Van Allen radiation belt. It was the heaviest astrophysical payload ever flown at that time at 16,300 kilograms (35,900 lb).
The General Coordinates Network (GCN), formerly known as the Gamma-ray burst Coordinates Network, is an open-source platform created by NASA to receive and transmit alerts about astronomical transient phenomena. This includes neutrino detections by observatories such as IceCube or Super-Kamiokande, gravitational wave events from the LIGO, Virgo and KAGRA interferometers, and gamma-ray bursts observed by Fermi, Swift or INTEGRAL. One of the main goals is to allow for follow-up observations of an event by other observatories, in hope to observe multi-messenger events.
Shrinivas Ramchandra Kulkarni is a US-based astronomer born and raised in India. He is currently a professor of astronomy and planetary science at California Institute of Technology, and he served as director of Caltech Optical Observatory (COO) at California Institute of Technology, in which capacity he oversaw the Palomar and Keck among other telescopes. He is the recipient of a number of awards and honours.
Astroparticle physics, also called particle astrophysics, is a branch of particle physics that studies elementary particles of astronomical origin and their relation to astrophysics and cosmology. It is a relatively new field of research emerging at the intersection of particle physics, astronomy, astrophysics, detector physics, relativity, solid state physics, and cosmology. Partly motivated by the discovery of neutrino oscillation, the field has undergone rapid development, both theoretically and experimentally, since the early 2000s.
Cornelis A. "Neil" Gehrels was an American astrophysicist specializing in the field of gamma-ray astronomy. He was Chief of the Astroparticle Physics Laboratory at NASA's Goddard Space Flight Center (GSFC) from 1995 until his death, and was best known for his work developing the field from early balloon instruments to today's space observatories such as the NASA Swift mission, for which he was the principal investigator. He was leading the WFIRST wide-field infrared telescope forward toward a launch in the mid-2020s. He was a member of the National Academy of Sciences and the American Academy of Arts and Sciences.
The history of gamma-ray began with the serendipitous detection of a gamma-ray burst (GRB) on July 2, 1967, by the U.S. Vela satellites. After these satellites detected fifteen other GRBs, Ray Klebesadel of the Los Alamos National Laboratory published the first paper on the subject, Observations of Gamma-Ray Bursts of Cosmic Origin. As more and more research was done on these mysterious events, hundreds of models were developed in an attempt to explain their origins.
GRB 990123 is a gamma-ray burst which was detected on January 23, 1999. It was the first GRB for which a simultaneous optical flash was detected. Astronomers first managed to obtain a visible-light image of a GRB as it occurred on January 23, 1999, using the ROTSE-I telescope in Los Alamos, New Mexico. The ROTSE-I was operated by a team under Dr. Carl W. Akerlof of the University of Michigan and included members from Los Alamos National Laboratory and Lawrence Livermore National Laboratory. The robotic telescope was fully automated, responding to signals from NASA's BATSE instrument aboard the Compton Gamma Ray Observatory within seconds, without human intervention. In the dark hours of the morning of January 23, 1999, the Compton satellite recorded a gamma-ray burst that lasted for about a minute and a half. There was a peak of gamma and X-ray emission 25 seconds after the event was first detected, followed by a somewhat smaller peak 40 seconds after the beginning of the event. The emission then fizzled out in a series of small peaks over the next 50 seconds, and eight minutes after the event had faded to a hundredth of its maximum brightness. The burst was so strong that it ranked in the top 2% of all bursts detected.
Gamma-ray astronomy is the astronomical observation of gamma rays, the most energetic form of electromagnetic radiation, with photon energies above 100 keV. Radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy.
The Hans A. Bethe Prize, is presented annually by the American Physical Society. The prize honors outstanding work in theory, experiment or observation in the areas of astrophysics, nuclear physics, nuclear astrophysics, or closely related fields. The prize consists of $10,000 and a certificate citing the contributions made by the recipient.
Fenton Hill Observatory is an astronomical research facility operated by Los Alamos National Laboratory in the Jemez Mountains of New Mexico, about 35 miles (56 km) west of Los Alamos. The site is home to several astronomical experiments and observatories spanning 30 acres (120,000 m2). It is also known as Technical Area 57 (TA-57) and is located at an elevation of 8,700 feet (2,700 m) in a region shielded from light pollution. Los Alamos National Laboratory has a use agreement with the Forest Service for the 30 acres (120,000 m2), which is located near Fenton Lake State Park.
The Robotic Optical Transient Search Experiment (ROTSE) is a multi-telescope experiment designed to observe the optical afterglow of gamma-ray bursts. The experiment currently consists of four telescopes located in Australia, Namibia, Turkey, and at the McDonald Observatory near Fort Davis, Texas.
Gerald Jay (Jerry) Fishman is an American research astrophysicist, specializing in gamma-ray astronomy. His research interests also include space and nuclear instrumentation and radiation in space. A native of St. Louis, Missouri, Fishman obtained a B.S. with Honors degree in physics from the University of Missouri in 1965, followed by M.S. and Ph.D. degrees in space science from Rice University in 1968 and 1970, respectively.
Timothy A. McKay is an astrophysicist and the Arthur F. Thurnau Professor of Physics at the University of Michigan. He is actively involved in physics education, including courses on “Physics for the Life Sciences” and Saturday Morning Physics. As of 2013, McKay's papers have over 30,000 citations and an h-index of 66. He considers publication and education vital to the scientific enterprise: “science isn’t science until you’ve shared it with someone else.”
Time-domain astronomy is the study of how astronomical objects change with time. Though the study may be said to begin with Galileo's Letters on Sunspots, the term now refers especially to variable objects beyond the Solar System. Changes over time may be due to movements or changes in the object itself. Common targets included are supernovae, pulsating stars, novas, flare stars, blazars and active galactic nuclei. Visible light time domain studies include OGLE, HAT-South, PanSTARRS, SkyMapper, ASAS, WASP, CRTS, GOTO and in a near future the LSST at the Vera C. Rubin Observatory.
The High Altitude Water Cherenkov Experiment or High Altitude Water Cherenkov Observatory is a gamma-ray and cosmic ray observatory located on the flanks of the Sierra Negra volcano in the Mexican state of Puebla at an altitude of 4100 meters, at 18°59′41″N97°18′30.6″W. HAWC is the successor to the Milagro gamma-ray observatory in New Mexico, which was also a gamma-ray observatory based around the principle of detecting gamma-rays indirectly using the water Cherenkov method.
Filippo Frontera is an Italian astrophysicist and professor, who deals with astronomical investigations on celestial gamma-rays.