IC 4687 | |
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![]() HST image of IC 4687 (center). | |
Observation data (J2000 epoch) | |
Constellation | Pavo |
Right ascension | 18h 13m 39.70s |
Declination | −57° 43′ 30.97″ |
Redshift | 0.017345 |
Heliocentric radial velocity | 5,200 km/s |
Distance | 253 Mly (76.95 Mpc) |
Apparent magnitude (V) | 0.33 |
Apparent magnitude (B) | 0.43 |
Characteristics | |
Type | Sb, Sd, HI;LIRG |
Size | 70,000 ly (estimated) |
Apparent size (V) | 1.3' x 0.9' |
Other designations | |
ESO 140-IG10, IRAS 18093-5744, PGC 61602, FAIRALL 045 |
IC 4687 known as IRAS 18093-5744 or F18093-5744, is an Sb spiral galaxy [1] located in the constellation of Pavo. It is located 250 million light years from Earth [2] and was discovered by Royal Harwood Frost on August 1, 1904, who described the object "as brighter middle with magnitude of 14. [3] It has a surface brightness of 12.5. [4]
IC 4687 is classified as a luminous infrared galaxy. It has an infrared-luminosity of 1011.3 LΘ, compatible with a star formation rate of 30 MΘ yr−1. [5] Through it has an energy output dominated by its star formation, the galaxy has a weak active galactic nucleus. [6]
The regions of IC 4687 are also known to contain high amounts of molecular gas surface densities of log ΣH2 (MΘ pc−2) = 2.9 ± 0.2. In additional, the galaxy is known to produce stars at a rapid rate when compared to normal star forming galaxies with the regions having log ΣSFR (MΘ yr−1 kpc−2) = 0.7 ± 0.4. This units are considered ~ 10 factor higher when compared to extreme values of nearby galaxies. [6] Not to mention, IC 4687 has a velocity field mainly controlled by rotation. It also has a defined kinematic center that is synchronous with its nucleus. [7]
IC 4687 forms an interacting galaxy trio with two other galaxies, IC 4686 and IC 4689. [8] Both of these galaxies are located ~ 10 and ~ 20 kiloparsecs away from IC 4687 and are classified as spiral-like with their velocity fields influenced by kinematic and rotation centers. [6] Because of its close merger with IC 4686, a starburst and wolf-raynet galaxy, IC 4687 appears distorted. The Hubble images shows the galaxy has a distorted morphology with interstellar dust and gas apparently obscuring its companion. [9] Not to mention, IC 4687 has large curly tidal tail as a result of the merger. [8] It is possible the weak interaction from IC 4686 might triggered its starburst. [6]