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Greek astrophysicist Kalogera among scientists to discover “Gravitational Waves”

For the first time, NASA scientists have detected light tied to a gravitational-wave event, thanks to two merging neutron stars in the galaxy NGC 4993, located about 130 million light-years from Earth in the constellation Hydra.

Astronomers announced on Monday that they had seen and heard a pair of dead stars collide, giving them their first glimpse of the violent process by which most of the gold and silver in the universe was created.

Gravitational waves are ripples in the curvature of spacetime that are generated in certain gravitational interactions and propagate as waves outward from their source at the speed of light.

Shortly after 8:41 a.m. EDT on Aug. 17, NASA’s Fermi Gamma-ray Space Telescope picked up a pulse of high-energy light from a powerful explosion, which was immediately reported to astronomers around the globe as a short gamma-ray burst. The scientists at the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves dubbed GW170817 from a pair of smashing stars tied to the gamma-ray burst, encouraging astronomers to look for the aftermath of the explosion. Shortly thereafter, the burst was detected as part of a follow-up analysis by ESA’s (European Space Agency’s) INTEGRAL satellite, NASA said on Monday.

Swift’s Ultraviolet/Optical Telescope imaged the kilonova produced by merging neutron stars in the galaxy NGC 4993 (box) on Aug.
Swift’s Ultraviolet/Optical Telescope imaged the kilonova produced by merging neutron stars in the galaxy NGC 4993 (box) on Aug. 18, 2017, about 15 hours after gravitational waves and the gamma-ray burst were detected. The source was unexpectedly bright in ultraviolet light. It faded rapidly and was undetectable in UV when Swift looked again on Aug. 29. This false-color composite combines images taken through three ultraviolet filters. Inset: Magnified views of the galaxy. Credits: NASA/Swift
“This is extremely exciting science,” said Paul Hertz, director of NASA’s Astrophysics Division at the agency’s headquarters in Washington. “Now, for the first time, we’ve seen light and gravitational waves produced by the same event. The detection of a gravitational-wave source’s light has revealed details of the event that cannot be determined from gravitational waves alone. The multiplier effect of study with many observatories is incredible.”

Among the scientists assigned to inform the public about the groundbreaking discovery was also Vicky Kalogera, a Greek astrophysicist and leading member of the LIGO Collaboration that observed the gravitational waves in 2015.

“For the first time ever, we have proof,” said Vicky Kalogera, an astronomer at Northwestern University.

Born in Thessaloniki, North Greece, in 1971 Vassiliki (Vicky) Kalogera studied Physics at the Aristoteles University, Kalogera moved to US, where she completed her PhD in astronomy in 1997 at the University of Illinois. She joined the Harvard-Smithsonian Center for Astrophysics as a CfA postdoctoral fellow and was awarded the Clay Fellowship in 2000. She joined the faculty in the Department of Physics and Astronomy at Northwestern University in 2001

She is a professor at Northwestern University and the Director of the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). She is a leading member of the LIGO Collaboration that observed gravitational waves in 2015.

Kalogera is a leading theorist in the study of gravitational waves, the emission of X-rays from compact binary objects and the coalescence of neutron-star binaries.

Vicky Kalogera: Discovering the sound of Black hole

Video from 2016 presentation.


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One comment

  1. Who cares whether she is amongst the scientists who made this discovery. Everyday hundreds of scientists from all around the world make discoveries, some are French others are Germains, Japanese, Indians, Pakestani, Egyptians, Chinese…who cares?!?