Brandeis Prof. John Wardle (PHYS) was amongst the group of scientists that assisted in generating the first image of a black hole ever captured. The black hole that this group of scientists photographed, and released to the public in early April, is at the center of Messier 87, which is in the Virgo galaxy cluster with a mass 6.5 billion times that of the sun and 55 million light-years away from Earth.
The announcement was made in a series of six papers that were published in a special issue of “The Astrophysical Journal Letters,” according to the Event Horizon Telescope (EHT) website.
The EHT is an international collaboration on improving the capability of the “Very Long Baseline Interferometry (VLBI) at short wavelengths in pursuit of this goal,” according to their website. Radio dishes around the world are connected to one another which helps create an interferometer, which measures the size of the emissions of two “supermassive black holes”: one, SgrA*, which lies at the center of the Milky Way and a second, M87, which sites in the center of the Virgo A galaxy, according to the website.
Wardle was a part of four different working groups that contributed to the project, the professor said in an interview with The Brandeis Hoot. In total, over 200 scientists around the world helped.
The four groups Wardle was a part of included: “one that helped with imaging, one that is looking at the polarization of radio waves, which is my particular speciality… one that was helping all the publications get refereed internally. And then the fourth one was looking at the more distant quasars,” Wardle said.
Together, all the working groups have used eight different telescopes around the world, according to Wardle, to observe the wavelengths produced by the black hole over the past four years. Data collection was completed in April 2017, according to a BrandeisNOW article.
The knowledge gained from this project also helps to further support Albert Einstein’s theory of general relativity (GR), a theory that has remained true for almost a century. “So what we’re doing is testing whether general relativity works all the way out to this regime of billion solar mass objects with huge amounts of bending of the light and orbiting light and so on,” explained Wardle. Until recently, GR was only tested within our solar system. The research done with the black hole, however, demonstrates that GR holds true as well.
Wardle has been part of the Brandeis physics department since 1979 and studying astrophysics since the late 1960s. On campus, Wardle is part of the Brandeis Radio Astronomy Group with Prof. David Roberts (PHYS), which “conducts research in extragalactic astrophysics and cosmology at wavelengths covering the entire electromagnetic spectrum, but especially radio wavelengths,” according to their official website. More specifically, they study what is at the core of various “active galaxies” or “blazars.”
Wardle studies radio waves and looks at “distant objects like quasars and centers of galaxies,” he said. He continued to explain that quasars are “galaxies with a very, very bright nucleus… They look almost like stars because you can’t see the surrounding galaxy. Quasar is a contraction of ‘quasi-star,’ or quasi-star object.”
Students interested in astronomy can join the Astronomy Club on campus, which seeks “to advance the awareness of the cosmos and optical observation of outer space,” according to their club description. The club works with the Physics Department to host events and utilizes the 24’’ Cassegrain primary telescope and the 8’’ Celestron finderscope to perform their celestial gazing.
