Webb Telescope & Gravitational Wave Revolution in Astrophysics

A depiction created by an artist, showing the gravitational waves produced by the merging of two neutron stars. Credit: R. Hurt/Caltech-JPL

April 21, 2023


Gravitational waves have been one of the most fascinating and mysterious phenomena in the field of astrophysics. These ripples in the fabric of spacetime, first predicted by Albert Einstein's general theory of relativity, were first detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015. The discovery of gravitational waves opened up a whole new window into the study of the universe, allowing scientists to observe the cosmos in an entirely new way. In this article, we will delve deeper into gravitational waves and discuss how the James Webb Space Telescope (JWST) will contribute to the ongoing research in this field.

What are Gravitational Waves?

Gravitational waves are essentially ripples in the fabric of spacetime caused by the acceleration of massive objects. According to Einstein's theory of general relativity, massive objects create a curvature in the fabric of spacetime, much like a heavy object placed on a trampoline would create a depression in the fabric of the trampoline. When two massive objects orbit around each other, they cause disturbances in the fabric of spacetime, which propagate outward as gravitational waves.

Gravitational waves are incredibly difficult to detect, as they are extremely faint and have a very low frequency. The first direct detection of gravitational waves was made by the LIGO observatory, which detected a signal from the collision of two black holes, located 1.3 billion light-years away. The detection of gravitational waves confirmed a prediction made by Einstein's theory of general relativity over a century ago and opened up a whole new avenue of research in astrophysics.

How does the James Webb Space Telescope contribute to Gravitational Wave research?

The James Webb Space Telescope, which was launched in 2021, is one of the most highly anticipated astronomical observatories of the century. With its advanced capabilities and cutting-edge technology, the JWST will be able to observe the universe in ways that were previously impossible. The JWST will be equipped with a suite of instruments that will allow scientists to study a wide range of astrophysical phenomena, including the study of gravitational waves.

One of the key instruments on the JWST that will contribute to the study of gravitational waves is the Near Infrared Camera (NIRCam). The NIRCam is a sensitive camera that is capable of detecting infrared light, which is emitted by objects that are too cool to emit visible light. The NIRCam will be used to observe black holes, which are one of the most important sources of gravitational waves.

Black holes are incredibly dense objects that are formed when massive stars collapse in on themselves. They are invisible to traditional telescopes, as they do not emit any light. However, when two black holes merge, they emit a burst of gravitational waves, which can be detected by observatories like LIGO. The JWST will be able to observe the aftermath of black hole mergers, by detecting the infrared radiation emitted by the debris left over from the merger. This will help scientists to study the properties of black holes and better understand the dynamics of their mergers.

Another key instrument on the JWST that will contribute to the study of gravitational waves is the Mid-Infrared Instrument (MIRI). The MIRI is a highly sensitive camera that is capable of detecting the heat radiation emitted by objects in the universe. This will be particularly useful for studying the aftermath of neutron star mergers, which are another important source of gravitational waves.

Neutron stars are incredibly dense objects that are formed when massive stars collapse in on themselves. They are made up of tightly packed neutrons and are some of the most extreme objects in the universe. When two neutron stars merge, they emit a burst of gravitational waves, which can be detected by observatories like LIGO. The JWST will be able to observe the aftermath of neutron star mergers, by detecting the infrared radiation emitted by the debris left over from the merger. This radiation is called a kilonova, and it can provide valuable information about the properties of neutron stars and the physics of their mergers.

The JWST will also be able to study the properties of the cosmic microwave background radiation (CMB), which is the radiation left over from the Big Bang. The CMB provides valuable information about the early universe and the formation of structures in the universe. By studying the CMB, scientists can gain insights into the nature of dark matter and dark energy, which are two of the biggest mysteries in astrophysics.

The JWST will be able to study the CMB with its Mid-Infrared Instrument (MIRI), which is capable of detecting the faint heat radiation emitted by the CMB. This will provide scientists with more detailed information about the CMB, allowing them to study the properties of the early universe with unprecedented precision.

In addition to its scientific capabilities, the JWST is also an engineering marvel. The telescope is incredibly complex, with many moving parts and delicate instruments. To ensure that the telescope functions properly, it will undergo extensive testing and calibration before it is launched. Once in space, the telescope will operate at a distance of 1.5 million kilometers from Earth, where it will be shielded from the Sun and Earth's radiation. This will allow the telescope to operate at extremely low temperatures, which are necessary for its infrared observations. 

The James Webb Space Telescope is one of the most highly anticipated astronomical observatories of the century. With its advanced capabilities and cutting-edge technology, the JWST will be able to observe the universe in ways that were previously impossible. In particular, the JWST will contribute to the ongoing research in the field of gravitational waves, by studying black hole mergers, neutron star mergers, and the cosmic microwave background radiation. The JWST is a testament to human ingenuity and the power of scientific exploration, and it promises to revolutionize our understanding of the universe