... Up: Other Galaxies with HI Previous: The peculiar galaxy NGC 4258: . The nearest and most prominent radio elliptical galaxy is NGC 5128 (Cen A). H I , OH, and H 2 CO absorption features have been detected near the systemic velocity of the galaxy (550 kms -1 ). ... Other radio elliptical galaxies detected in H I absorption are NGC 315, NGC 1275, NGC 3894, NGC 5363, 3C236, and 4C31.06, bringing the number of detections up to eight (van Gorkom et al. 1989, and references therein). ...

metrologia The leap second: its history and possible future R. A. Nelson, D. D. McCarthy , S. Malys, J. Levine, B. Guinot, H. F. Fliegel , R. L. Beard and T. R. Bartholome w Abstract. This paper reviews the theoretica l motivatio n for the leap second in the context of the historica l evolutio n of time measurement . Th e periodic insertio n of a leap second step into th e scale of Coordinate d Universal Time (UTC) necessitates frequent changes in comple x timekeepin g systems an d is currentl y th e