ESO has published an image of the galaxy NGC 1365, also known as The Great Barred Spiral Galaxy, captured with the MUSE instrument mounted on the VLT in Chile. The nickname is due to its particular shape with two structures running from its center that extend to its borders. It’s an uncommon type of galaxy since about 15% of galaxies belong to it while spiral ones are common. In this case, there’s a second bar inside the main one. The observations conducted with MUSE will help to understand the dynamics of the stars within NGC 1365 and its supermassive black hole.
About 56 million light-years from Earth, the galaxy NGC 1365 is part of the Furnace cluster. Despite its distance, it’s bright thanks to its active galactic nucleus, powered by a supermassive black hole that significantly heats the materials around it. The mass of that black hole has been estimated to be around two million times the Sun’s, less than half the one in the center of the Milky Way but extreme in other ways according to the results of a calculation of its rotation speed.
The influence of the supermassive black hole on the shape of the galaxy NGC 1365 is yet to be accurately assessed. The presence of the double bar extending from the center to the borders of NGC 1365, where it extends into two spiral arms, is attributed to the combination of the rotation of the galaxy and the complex dynamics of the stars that form the bar and arms. A second bar is nested within the main one, and probably moves independently.
Due to these complex dynamics, the galaxy NGC 1365 has already been the subject of several studies. The VLT (Very Large Telescope) was also used in the past to observe it with different instruments. An article published in the journal “Astronomy & Astrophysics” in February 2019 reported the results of observations conducted at near infrareds using the SINFONI instrument within the NUGA (NUclei of GAlaxies) project. This time, the observations were conducted using the MUSE (Multi-Unit Spectroscopic Explorer) instrument within the TIMER (Time Inference with MUSE in Extragalactic Rings) survey on galactic disks.
The image published by ESO shows the galaxy NGC 1365 at optical and infrared wavelengths showing gas and dust in its central region. This helps to understand the dynamics related to the action of the supermassive black hole, star formation, and star movements. It’s a typical case in which the result is an image that is spectacular and at the same time useful for scientific research.