It won’t be another 15 years or so before the Laser Interferometer Space Antenna (LISA) observatory is launched into outer space, but astronomers are already excited about the potential discoveries its launch could yield. A new study, in fact, suggests that LISA might be able to detect “dozens” of binaries, or pairs of gravitationally bound, orbiting compact objects, in Milky Way’s globular clusters.
A news release published in EurekAlert described the study published Friday by a team of Northwestern University researchers, which suggests that our galaxy might be teeming with binaries, and that LISA would be able to spot these pairings of objects. The binaries might include a variety of pairings, including combinations that include black holes, neutron stars, and white dwarf stars alongside more conventional counterparts. Interestingly, the researchers also predicted that LISA could find binaries that have their own peculiarities that set them apart from those that formed in isolation.
As further noted in the EurekAlert news release, the Northwestern study, which was published in the journal Physical Review Letters, is the first of its kind to predict LISA binary sources with globular cluster models. LISA is expected to launch in 2034, with capabilities that allow it to detect lower frequency gravitational waves than those spotted by the Laser Interferometer Gravitational-Wave Observatory (LIGO), an Earth-bound observatory best known for being the first to detect gravitational waves from distant black hole collisions.
“LISA is sensitive to Milky Way systems and will expand the breadth of the gravitational wave spectrum, allowing us to explore different types of objects that aren’t observable with LIGO,” said study first author Kyle Kremer, a physics and astronomy doctoral student at Northwestern University’s Weinberg Colleges of Arts and Sciences.
— Fraser Cain (@fcain) May 12, 2018
The methodologies used by Kremer and his colleagues included the analysis of over 100 “fully evolved” globular cluster models similar to the 150 or so that have been confirmed so far to exist in our galaxy. These models were created at Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), and were tested on the university’s Quest cluster of supercomputers, which only take a few days to predict the entire 12-billion-year lifespan of the average globular cluster.
“This study is helping us understand what science is going to be contained in the LISA data,” said CIERA associate director and study co-author Shane Larson.
All in all, the researchers believe that LISA will be able to detect binaries in about a third of the Milky Way’s known globular clusters. Furthermore, the study suggests that LISA will be able to detect about eight black hole binaries in Milky Way’s neighboring galaxy Andromeda, and about 10 times as many in Virgo, another nearby galaxy.