A member of one of the two main classes of X-ray binary systems where one of the components is a neutron star or black hole and the other component a low-mass star with a spectral type A or later. LMX
Bs mainly emit soft X-rays. The ratio of their optical to X-ray luminosities is less than 0.1. They belong to old stellar populations with ages 5-15 x 10^9 years and are found in globular clusters and in the bulge of our Milky Way galaxy; some are also found in the disk. Hercules X-1 is an example of LMXBs.
A member of one of the two main classes of X-ray binary systems where one of the components is a neutron star or black hole and the other component a low-mass star with a spectral type A or later. LMX
Bs mainly emit soft X-rays. The ratio of their optical to X-ray luminosities is less than 0.1. They belong to old stellar populations with ages 5-15 x 10^9 years and are found in globular clusters and in the bulge of our Milky Way galaxy; some are also found in the disk. Hercules X-1 is an example of LMXBs.
A member of one of the two main classes of X-ray binary systems where one of the components is a neutron star or black hole and the other component a low-mass star with a spectral type A or later. LMX
Bs mainly emit soft X-rays. The ratio of their optical to X-ray luminosities is less than 0.1. They belong to old stellar populations with ages 5-15 x 10^9 years and are found in globular clusters and in the bulge of our Milky Way galaxy; some are also found in the disk. Hercules X-1 is an example of LMXBs.
A member of a particularly faint population of galaxies with a central surface brightness below the brightness of the background sky. The central regions of many of them resemble a dwarf galaxy, but m
ost of the mass is contained in a large gaseous disk of low density that is observable only with long-exposure optical images or at radio wavelengths. Some are as massive as a large spiral galaxy, for example Malin 1. The proportion of LSBGs relative to normal galaxies is unknown. They may however represent a significant fraction of mass in the Universe. LSBGs are thought to be primitive systems because they have total masses similar to normal galaxies, but have typically converted less than 10% of their gas into stars. Spiral LSBGs do not obey Freeman's law.