Green Bank WV (SPX) Jan 13, 2022 An international team of astronomers has discovered what could be...
An international team of astronomers has discovered what could be the early sign of a background signal arising from supermassive black holes, observed through low-frequency gravitational waves.
Gravitational Waves ripple through spacetime at a light-year-scale, and could originate from mergers of the most massive black holes in the Universe-or from events occurring soon after the formation of the Universe in the Big Bang.
The characteristics of this common-among-pulsars signal are in broad agreement with those expected from a GW "Background".
This background is formed by many different overlapping GW signals emitted from the cosmic population of supermassive binary black holes, analogous to background noise from the many overlapping voices in a crowded hall.
The "Smoking gun" for a gravitational wave detection is a unique relationship in the strength of the signal between pulsars in different parts of the sky.
While these "Spatial correlations" have not yet been detected, the existing signal is consistent with what scientists expect to see at first.
The IPTA is working diligently to analyze more recent data, which could confirm the nature of the new signal.
Dr. Maura McLaughlin of West Virginia University, who uses the GBT for data collection for NANOGrav, says that, "If the signal we are currently seeing is the first hint of a GWB, then based on our simulations, it is possible we will have more definite measurements of the spatial correlations necessary to conclusively identify the origin of the common signal in the near future."
The Green Bank Observatory is developing new technology to enhance the GBT's capabilities for this research, "New instruments, like our upcoming ultrawideband receiver , will ensure that the GBT continues to make essential contributions to NANOGrav and the IPTA. If what we are seeing here is indeed the signature of gravitational waves, then the next few years are going to be really exciting."
The discovery of a supermassive black hole in a relatively small galaxy could help astronomers unravel the mystery surrounding how the very biggest black holes grow.