The Center for Astrophysics | Harvard & Smithsonian
The Center for Astrophysics | Harvard & Smithsonian
Support Our Science

Ramesh Narayan

Center for Astrophysics
Professor/Astrophysicist
Share this Page
Research Topics
Science Fields
Divisions
My Workspace
Ramesh Narayan
rnarayan@cfa.harvard.edu

About

Ramesh Narayan is the Thomas Dudley Cabot Professor of the Natural Sciences in the Department of Astronomy at Harvard University. He is an astrophysicist who is recognized for his wide-ranging research in the area of high energy astrophysics.

He is known particularly for his work on black holes, where he has developed theoretical models of different modes of accretion and has used astronomical observations to elucidate the physical nature of both the accretion flow and the black hole.

Narayan was born in Mumbai, India in 1950 and became a U.S. citizen in 2010. He grew up in Madras (currently called Chennai), India, graduated with a B.Sc. in physics from Madras University, and received a doctorate from Bangalore University in 1979. He was on the faculty of the University of Arizona before joining Harvard University in 1991, where he has served as the chair of the Department of Astronomy. He currently serves as one of the Principal Investigators for the Harvard Black Hole Initiative.

He is a member of the National Academy of Sciences, and is also a Fellow of the Royal Society (London), the American Association for the Advancement of Science and The World Academy of Sciences.

Using primarily theoretical methods, Narayan studies a variety of astronomical objects and phenomena with the goal of understanding the physical processes at work. Research topics he has worked on include accretion disks, active galactic nuclei, black holes, galaxy clusters, gamma-ray bursts, gravitational lensing, gravitational waves, image restoration, neutron stars, pulsars, and scintillation.

In the area of black holes, Narayan has studied a previously poorly-understood mode of accretion called radiatively inefficient accretion, and has shown that the vast majority of black holes in the universe accrete via this mode. Using accretion disks as a probe, he and his colleagues have developed methods to measure the spin parameters of black holes. They have also demonstrated that astronomical black holes very likely do possess event horizons, as predicted by the general theory of relativity. In recent years, Narayan has used numerical simulations to study the physics of magnetized accretion and relativistic jet ejection in the strong field gravity of a black hole. He is a member of the Event Horizon Telescope Collaboration.

B.Sc. (Physics), Madras University, India and (Ph.D.), Physics, Bangalore University, India

Telescopes and Instruments

Chandra

The Chandra X-ray Observatory is NASA’s flagship X-ray observatory, providing essential data on everything from the environment surrounding newborn stars to the emissions from hot plasma inside galaxy clusters. The Smithsonian Astrophysical Observatory (SAO), as part of the Center for Astrophysics | Harvard & Smithsonian, manages Chandra’s day-to-day operations, providing spacecraft control, observation planning, and data processing for astronomers. Chandra is one of NASA’s orbiting Great Observatories, along with the Hubble.

Visit the Chandra Website
1

Event Horizon Telescope (EHT)

Black holes are found in the centers of most galaxies, where they can influence star formation and the distribution of atoms in the environment surrounding them. However, direct observation of a black hole is difficult because it is so small relative to their masses. Founded by Shep Doeleman at the Center for Astrophysics | Harvard & Smithsonian, the Event Horizon Telescope (EHT) captured the first image ever taken of a black hole: specifically, the ring of light produced by matter just as it falls into the black hole at the center of the nearby galaxy M87. The EHT is a virtual observatory consisting of telescopes spanning the planet, from Greenland to the South Pole. The international collaboration operating the EHT includes observatories affiliated with the Center for Astrophysics: the CfA’s Submillimeter Array (SMA) and the Greenland Telescope.

Visit the EHT Website
2

The Greenland Telescope

The polar regions are challenging environments for humans, but worthwhile for astronomy with their long nights and often-clear skies. The Greenland Telescope is the latest telescope to be placed in the Arctic, as part of the Event Horizon Telescope (EHT) project to capture the first images of black holes. The telescope operates in the region of the spectrum where infrared and radio light meet, which is ideal for looking into the dense central region of the Milky Way, where our galaxy’s supermassive black hole resides. The Greenland Telescope is jointly operated by the Center for Astrophysics | Harvard & Smithsonian and the Academia Sinica Institute of Astronomy & Astrophysics (ASIAA) of Taiwan.

Visit the Greenland Telescope Website
3

The Submillimeter Array - Maunakea, HI

Located near the summit of Maunakea on the Big Island of Hawaii, the Submillimeter Array (SMA) is one of the flagship observatories of the Center for Astrophysics | Harvard & Smithsonian. The observatory consists of eight radio dishes working together as one telescope, giving astronomers a window on a wide range of astronomical objects and phenomena: planets and comets in our own Solar System; the birth of stars and planets; and the supermassive black holes hidden at the centers of the Milky Way and other galaxies. The SMA is operated jointly by the CfA and the Academia Sinica in Taiwan.

Visit the Submillimeter Array Website
4