May 9, 2024

More Than Meets the Eye: Hubble Misses Vast Amounts of Energy

Credit: ESA/Hubble, A. Riess et al., J. Greene
Meet NGC 5728, a spiral galaxy around 130 million light-years from Earth. This image was caught utilizing Hubbles Wide Field Camera 3 (WFC3), which is very delicate to noticeable and infrared light. For that reason, this image wonderfully catches the regions of NGC 5728 that are giving off infrared and visible light. However, there are many other kinds of light that galaxies such as NGC 5728 can release, which WFC3 can not see.
In this image, NCG 5728 appears to be an elegant, luminous, disallowed spiral galaxy. What this image does not reveal, nevertheless, is that NGC 5728 is also a monumentally energetic kind of galaxy, known as a Seyfert galaxy.
This incredibly energetic class of galaxies are powered by their active cores, which are understood as active galactic nuclei (AGNs). There are many various kinds of AGNs, and just a few of them power Seyfert galaxies.

NGC 5728, like all Seyfert galaxies, is identified from other galaxies with AGNs since the galaxy itself can be seen clearly. Other types of AGNs, such as quasars, discharge a lot radiation that it is nearly difficult to observe the galaxy that houses them.
As this image shows, NGC 5728 is clearly observable, and at optical and infrared wavelengths it looks rather typical. It is interesting to know that the galaxys center is emitting vast quantities of light in parts of the electro-magnetic spectrum that WFC3 simply isnt sensitive to!
Just to make complex things, the AGN at NGC 5728s core might really be releasing some visible and infrared light– however it might be obstructed by the dust surrounding the galaxys core.