Magnitude +11.2 face-on spiral galaxy NGC 6814 lies in the constellation Aquila, 74.4 million light-years from Earth. Click the image for a full-size view. Image credit: ESA/Hubble & NASA. Acknowledgement: Judy Schmidt.Spiral galaxies together with irregular galaxies make up approximately 60 percent of the galaxies in the local Universe. However, despite their prevalence, each spiral galaxy is unique — like snowflakes, no two are alike. This is demonstrated by the striking face-on spiral galaxy NGC 6814, whose luminous nucleus and spectacular sweeping arms, rippled with an intricate pattern of dark dust, are captured in this NASA/ESA Hubble Space Telescope image.
NGC 6814 has an extremely bright nucleus, a telltale sign that the galaxy is a Seyfert galaxy. These galaxies have very active centres that can emit strong bursts of radiation. The luminous heart of NGC 6814 is a highly variable source of X-ray radiation, causing scientists to suspect that it hosts a supermassive black hole with a mass about 18 million times that of the Sun.
As NGC 6814 is a very active galaxy, many regions of ionised gas are studded along its spiral arms. In these large clouds of gas, a burst of star formation has recently taken place, forging the brilliant blue stars that are visible scattered throughout the galaxy.
Astronomers using observations from the NASA/ESA Hubble Space Telescope and NASA’s Chandra X-ray Observatory have studied how dark matter in clusters of galaxies behaves when the clusters collide. The results show that dark matter interacts with itself even less than previously thought, and narrows down the options for what this mysterious substance might be.
Astronomers have used NASA’s Chandra X-ray Observatory to discover a jet from a very distant supermassive black hole being illuminated by the oldest light in the universe. This discovery shows that black holes with powerful jets may be more common than previously thought in the first few billion years after the Big Bang.
At first glance this NASA/ESA Hubble Space Telescope image seems to show an array of different cosmic objects, but the speckling of stars shown here actually forms a single body — a nearby dwarf galaxy known as Leo A. Its few million stars are so sparsely distributed that some distant background galaxies are visible through it.
