NGC 3758 known as the Owl Galaxy,[1] is a type Sb[2] spiral galaxy in the constellation of Leo.[3][4] It is located 447 million light-years from the Solar System and an approximate diameter of 70,000 light-years.[5] NGC 3758 was discovered by Ralph Copeland on March 18, 1874, but also independently discovered by Edouard Stephan ten years later.[1]
| NGC 3758 | |
|---|---|
 DECam image of NGC 3758 | |
| Observation data | |
| Constellation | Leo |
| Right ascension | 174.12 degrees |
| Declination | 21.59 degrees |
| Redshift | 0.029771 |
| Heliocentric radial velocity | 8,909 km/s |
| Distance | 447 Mly (137 Mpc) |
| Apparent magnitude (V) | 14.3 |
| Characteristics | |
| Type | Sab pec, Sy1 |
| Size | 70,000 ly |
| Notable features | Rare example of binary active galactic nucleus, seyfert galaxy |
| Other designations | |
| PGC 35905, CGCG 126-110, KUG 1133+218, MCG +04-27-073, IRAS 11338+2152, REIZ 1338, PGC 165579, AKRAI J1136286+213546, RBS 1003, NVSS J113629+213549, SFRS 149, Mrk 739, 1RXS J113629.4+213552, LEDA 35905 | |
Description
NGC 3758 is classified as a Seyfert 1 type galaxy.[5][6] It is classified a Markarian galaxy (designated Mrk 739), because compared to other galaxies its nucleus emits excessive amounts of ultraviolet rays.[7] It is a binary active galactic nucleus galaxy, a rare example of a galaxy merger.[8][9]
NGC 3758 is made up of two separate galaxies, NGC 3758W[10] and NGC 3758E.[11] Each of the two galaxies has a supermassive black hole, which is only 11,000 light-years apart and gorging on infalling gas.[12] Both black holes are active, in which large amounts of gas is sent spiraling inward, which it becomes hot and radiates energy.[9] The galaxies are gravitationally bound together and such, their orbits will dynamically decay until their nuclei merge in which the process takes a few billion years.[13]
The galaxy has an appearance of a friendly-looking object complete with two cores as the eyes and a swirling grin.[12] It is possible that binary black holes on the verge of merging in NGC 3758 can turn stars into hypervelocity stars and catapult them out of their host galaxy.[14]
NGC 3758 contains an extended emission-line region (EELR), which was discovered in the Galaxy Zoo project. This EELR could originate from both AGN or from just one. Detailed oxygen [O III] imaging could reveal which AGN is responsible for this EELR.[15] ESO's VLT MUSE instrument is capable of such observations and MUSE did observe NGC 3758 in 2016,[16] but no publication about the MUSE data concerning the EELR exists as of May 2024.