Subrahmanyan Chandrasekhar was an Indian-American theoretical physicist who made significant contributions to the scientific knowledge about the structure of stars, stellar evolution and black holes. He was awarded the 1983 Nobel Prize in physics along with William A. Fowler for "...theoretical studies of the physical processes of importance to the structure and evolution of the stars". His mathematical treatment of stellar evolution yielded many of the current theoretical models of the later evolutionary stages of massive stars and black holes. Many concepts, institutions and inventions, including the Chandrasekhar limit and the Chandra X-Ray Observatory, are named after him.
A radio galaxy is a galaxy with giant regions of radio emission extending well beyond its visible structure. These energetic radio lobes are powered by jets from its active galactic nucleus. They have luminosities up to 1039 W at radio wavelengths between 10 MHz and 100 GHz. The radio emission is due to the synchrotron process. The observed structure in radio emission is determined by the interaction between twin jets and the external medium, modified by the effects of relativistic beaming. The host galaxies are almost exclusively large elliptical galaxies. Radio-loud active galaxies can be detected at large distances, making them valuable tools for observational cosmology. Recently, much work has been done on the effects of these objects on the intergalactic medium, particularly in galaxy groups and clusters.
Messier 87 is a supergiant elliptical galaxy in the constellation Virgo that contains several trillion stars. One of the largest and most massive galaxies in the local universe, it has a large population of globular clusters—about 15,000 compared with the 150–200 orbiting the Milky Way—and a jet of energetic plasma that originates at the core and extends at least 1,500 parsecs, traveling at a relativistic speed. It is one of the brightest radio sources in the sky and a popular target for both amateur and professional astronomers.
Kip Stephen Thorne is an American theoretical physicist and writer known for his contributions in gravitational physics and astrophysics. Along with Rainer Weiss and Barry C. Barish, he was awarded the 2017 Nobel Prize in Physics for his contributions to the LIGO detector and the observation of gravitational waves.
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are", which is studied in celestial mechanics.
Rashid Alievich Sunyaev is a German, Soviet, and Russian astrophysicist of Tatar descent. He got his MS degree from the Moscow Institute of Physics and Technology (MIPT) in 1966. He became a professor at MIPT in 1974. Sunyaev was the head of the High Energy Astrophysics Department of the Russian Academy of Sciences, and has been chief scientist of the Academy's Space Research Institute since 1992. He has also been a director of the Max Planck Institute for Astrophysics in Garching, Germany since 1996, and Maureen and John Hendricks Distinguished Visiting Professor in the School of Natural Sciences at the Institute for Advanced Study in Princeton since 2010. In February 2022, he signed an open letter from Russian scientists and science journalists condemning Russia's invasion of Ukraine.
Martin John Rees, Baron Rees of Ludlow, is a British cosmologist and astrophysicist. He is the fifteenth Astronomer Royal, appointed in 1995, and was Master of Trinity College, Cambridge, from 2004 to 2012 and President of the Royal Society between 2005 and 2010. He has received various physics awards including the Wolf Prize in Physics in 2024 for for fundamental contributions to high-energy astrophysics, galaxies and structure formation, and cosmology.
Andrea Mia Ghez is an American astrophysicist, Nobel laureate, and professor in the Department of Physics and Astronomy and the Lauren B. Leichtman & Arthur E. Levine chair in Astrophysics, at the University of California, Los Angeles. Her research focuses on the center of the Milky Way galaxy.
An astrophysical jet is an astronomical phenomenon where outflows of ionised matter are emitted as extended beams along the axis of rotation. When this greatly accelerated matter in the beam approaches the speed of light, astrophysical jets become relativistic jets as they show effects from special relativity.
Peter Goldreich is an American astrophysicist whose research focuses on celestial mechanics, planetary rings, helioseismology and neutron stars. He is the Lee DuBridge Professor of Astrophysics and Planetary Physics at California Institute of Technology. Since 2005 he has also been a professor at the Institute for Advanced Study in Princeton, New Jersey. Asteroid 3805 Goldreich is named after him.
Kenneth Irwin Kellermann is an American astronomer at the National Radio Astronomy Observatory. He is best known for his work on quasars. He won the Helen B. Warner Prize for Astronomy of the American Astronomical Society in 1971, and the Bruce Medal of the Astronomical Society of the Pacific in 2014.
Reinhard Genzel is a German astrophysicist, co-director of the Max Planck Institute for Extraterrestrial Physics, a professor at LMU and an emeritus professor at the University of California, Berkeley. He was awarded the 2020 Nobel Prize in Physics "for the discovery of a supermassive compact object at the centre of our galaxy", which he shared with Andrea Ghez and Roger Penrose. In a 2021 interview given to Federal University of Pará in Brazil, Genzel recalls his journey as a physicist; the influence of his father, Ludwig Genzel; his experiences working with Charles H. Townes; and more.
The Blandford–Znajek process is a mechanism for the extraction of energy from a rotating black hole, introduced by Roger Blandford and Roman Znajek in 1977. This mechanism is the most preferred description of how astrophysical jets are formed around spinning supermassive black holes. This is one of the mechanisms that power quasars, or rapidly accreting supermassive black holes. Generally speaking, it was demonstrated that the power output of the accretion disk is significantly larger than the power output extracted directly from the hole, through its ergosphere. Hence, the presence of a poloidal magnetic field around the black hole is not determinant in its overall power output. It was also suggested that the mechanism plays a crucial role as a central engine for a gamma-ray burst.
Swift J164449.3+573451, initially referred to as GRB 110328A, and sometimes abbreviated to Sw J1644+57, was a tidal disruption event (TDE), the destruction of a star by a supermassive black hole. It was first detected by the Swift Gamma-Ray Burst Mission on March 28, 2011. The event occurred in the center of a small galaxy in the Draco constellation, about 3.8 billion light-years away. It was the first confirmed jetted tidal disruption event and is the most luminous and energetic TDE recorded.
The Event Horizon Telescope (EHT) is a telescope array consisting of a global network of radio telescopes. The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Earth, which form a combined array with an angular resolution sufficient to observe objects the size of a supermassive black hole's event horizon. The project's observational targets include the two black holes with the largest angular diameter as observed from Earth: the black hole at the center of the supergiant elliptical galaxy Messier 87, and Sagittarius A*, at the center of the Milky Way.
The Greenland Telescope is a radio telescope situated at the Thule Air Base in north-western Greenland. It will later be deployed at the Summit Station research camp, located at the highest point of the Greenland ice sheet at an altitude of 3,210 meters.
Reva Kay Williams is a theoretical astrophysicist. She is the first person to successfully work out the Penrose process using Einstein's Theory of Relativity to extract energy from black holes. Also, she is the first Black American woman to earn a PhD in theoretical astrophysics. Her work focuses on general relativistic astrophysics.
Ramesh Narayan is an Indian-American theoretical astrophysicist, currently the Thomas Dudley Cabot Professor of the Natural Sciences in the Department of Astronomy at Harvard University. Full member of the National Academy of Sciences, Ramesh Narayan is widely known for his contributions on the theory of black hole accretion processes. He is involved in the Event Horizon Telescope project, which led in 2019 to the first image of the event horizon of a black hole.
Monika Mościbrodzka is a Polish astrophysicist who is a professor at Radboud University Nijmegen. She is an expert in general relativistic plasma dynamics and numerical astrophysics. She was part of the Event Horizon Telescope team who contributed to the first direct image of a black hole, supermassive black hole M87*. She was awarded the 2022 Dutch Research Council Athena Prize and the 2023 Eddington Medal of the Royal Astronomical Society.
PKS 0226-559 known as PMN J0228-5546 is a quasar located in the constellation Horologium. At the redshift of 2.464, the object is roughly 10.6 billion light-years from Earth.
