ESO’s Very Large Telescope (VLT) has imaged the result of an impressive cosmic collision – the galaxy NGC 7727. A press release from the ESO Science Outreach Network (ESON).
What: ESON 16. August 2022.
August 16, 2022 – The giant NGC 7727 was formed from the merger of two galaxies, an event that began regarding a billion years ago. At its center is the closest pair of supermassive black holes ever found – two objects destined to merge into an even more massive black hole.
Just as you can collide with someone on a busy street, galaxies can collide. Although such galactic collisions are much more violent than a jostle down a busy street, individual stars generally do not encounter one another because the distances between them are very large compared to their size. Rather, the galaxies dance around each other, with gravity causing tidal forces that dramatically alter the appearance of the two dance partners. Tidal tails of stars, gas, and dust are slung around the galaxies as they eventually form a new, merged galaxy, resulting in the disordered yet beautiful asymmetric shape we see in NGC 7727.
The followingmath of this cosmic collision can be seen in this image of the galaxy obtained with the FOcal Reducer and Low Dispersion Spectrograph 2 (FORS2) on VLT the IT’S was recorded, impressive to see. While the galaxy was previously owned by another IT’Stelescope, this new image reveals even more detail in both the main body of the galaxy and the faint tidal tails around it.
On this VLTimage we see the tortuous paths created by the merger of the two galaxies, stripping stars and dust apart to form the unusual long arms that encircle NGC 7277. Portions of these arms are dotted with stars, which appear as bright bluish-purple specks in this image.
The image was acquired with the MUSE instrument on the Very Large Telescope (VLT) the IT’S taken at the Paranal Observatory in Chile. (Picture: IT’S/Voggel et al.)
Also visible in this image are two bright points at the galaxy’s center: another telltale sign of its dramatic past. The core of NGC 7727 still consists of the two original galactic cores, each hosting a supermassive black hole. Located regarding 89 million light-years from Earth in the constellation of Aquarius, this is the closest pair of supermassive black holes to us.
The black holes in NGC 7727 are only 1600 light-years apart on the sky and are expected to merge within 250 million years, which is the blink of an eye in astronomical time. When the two black holes merge, an even more massive black hole will form.
The search for similarly occluded pairs of supermassive black holes is set to begin with the forthcoming Extremely Large Telescope (ELT) of the IT’S, which is scheduled to become operational in Chile’s Atacama Desert later this decade, will take a giant leap forward. With the ELT, we can expect many more such discoveries at the centers of galaxies.
Our home galaxy, which also has a supermassive black hole at its center, will merge with its nearest large neighboring galaxy, the Andromeda galaxy, in a few billion years. Perhaps the nascent galaxy will look similar to the cosmic dance we see in NGC 7727, so this image might give us a glimpse into the future.
NGC 7727 is home to the pair of supermassive black holes closest to Earth to date. It is also the pair with the closest separation between two supermassive black holes found so far – the distance in the sky is only 1600 light-years. (Picture: IT’S/Digitized Sky Survey 2. Acknowledgement: Davide De Martin)
Further information
This image was created as part of the Cosmic Gems program IT’S (literally “cosmic gems”), an initiative to create astronomical images of scientifically interesting and visually appealing objects IT’S-Telescopes for education and outreach. The program uses telescope time that would not be suitable for scientific observations. The collected data can also be used for scientific purposes and will therefore also be available to astronomers via the scientific archive of the IT’S made available.
The European Southern Observatory (IT’S) empowers women scientists worldwide to uncover the mysteries of the universe for the benefit of all. We design, build and operate world-class observatories that women astronomers use to answer exciting questions and spark the excitement of astronomy. We also promote international cooperation in astronomy. the IT’S was founded in 1962 as an intergovernmental organization and is now represented by 16 member countries (Belgium, Denmark, Germany, France, Finland, Ireland, Italy, the Netherlands, Austria, Poland, Portugal, Sweden, Spain, Switzerland, the Czech Republic and the United Kingdom ) and the host country Chile and Australia as strategic partners. The headquarters of IT’S and their visitor center and planetarium, the IT’S Supernova, are located near Munich, Germany, while the Chilean Atacama Desert, a wonderful place with unique conditions for observing the sky, hosts our telescopes. the IT’S operates three observation sites: La Silla, Paranal and Chajnantor. At the Paranal site, the IT’S the Very Large Telescope and its associated Very Large Telescope Interferometer, and two survey telescopes, VISTA, which operates in the infrared, and the VLT Visible Light Survey Telescope. Also on the Paranal, the IT’S operate the Cherenkov Telescope Array South, the largest and most sensitive gamma-ray observatory in the world. Together with international partners, the IT’S on Chajnantor APEX and ALMA, two facilities for observing the sky in the millimeter and submillimeter range. On Cerro Armazones near Paranal we are building “the world’s largest eye in the sky” – the Extremely Large Telescope of the IT’S. From our offices in Santiago de Chile we support our activities in the country and work together with Chilean partners and society.
The translations from English speakers IT’S-Press releases are a service of IT’S Science Outreach Network (ESON), an international astronomical outreach network that brings together scientists and science communicators from all over the world IT’S-Member countries (and some other states) are represented. This is the German node of the network House of Astronomy in Heidelberg.
