UGC 7183,MCG +09-20-106, CGCG 269-038,IRAS 12085+5045,PGC 38795, 6C B120833.1+504537
NGC 4157 is aspiral galaxy in the constellationUrsa Major. The galaxy lies about 55 millionlight years away from Earth, which means, given its apparent dimensions, that NGC 4157 is approximately 125,000 light years across.[1] It was discovered byWilliam Herschel on March 9, 1788.[3]
NGC 4157 seen nearly edge-on, with an inclination of 84° based on CO imaging.[4] The totalstellar mass of NGC 4157 is(2.92±0.04)×1010M☉,[5] while the dust mass is estimated to be2.1×107M☉.[6] The hydrogen disk of NGC 4157 is symmetric and slightly wrapped, indicating no strong interaction with other galaxies, and extends to twice the size of the optical disk.[7] The total HI mass in the galaxy is estimated to be109.72M☉.[7]
The star formation rate of the galaxy is1.76±0.18 M☉ per year.[5] A star formation area is visible beyond the end of the optical disk and is also visible in X-ray and ultraviolet imaging. It could probably be the result of a recent accretion.[8]
The galaxy has radio emission extending above and below the optical disk, indicating the presence of a radio halo. There is also radio emission extending southwards from the north-eastern end of the disk.[6]
^Yim, Kijeong; Wong, Tony; Xue, Rui; Rand, Richard J.; Rosolowsky, Erik; Hulst, J. M. van der; Benjamin, Robert; Murphy, Eric J. (1 December 2014). "The Interstellar Medium and Star Formation in Edge-On Galaxies. Ii. NGC 4157, 4565, and 5907".The Astronomical Journal.148 (6): 127.arXiv:1408.5905.Bibcode:2014AJ....148..127Y.doi:10.1088/0004-6256/148/6/127.
