3 The Galactic Pulsar Population 

Soon after the discovery of pulsars, it was realised that the observed is heavily biased towards the brighter, nearby objects and probably represents only the tip of the iceberg of a much larger underlying population [67]. The extent to which the sample is incomplete is well demonstrated by the cumulative number distribution of pulsars as a function of distance projected onto the Galactic plane shown in Fig.  8 . Here the observed distribution (solid line) is compared to the expected distribution for a uniform disk population in which there are no such selection effects (dashed line). We see that the observed sample becomes strongly deficient in terms of the number of sources for distances beyond a few kpc.

  

Figure 8: Cumulative number of observed pulsars (solid line) as a function of projected distance from the Sun. The dashed line shows the expected distribution for a hypothetical uniform disk Galaxy with a radius of 15 kpc in which all pulsars can be seen.

This incompletion is a result of a number of different selection effects present in pulsar searches which we now discuss in some detail.

• 3.1 Selection Effects in Pulsar Searches
• 3.2 Correcting the observed pulsar sample
• 3.3 The Population of Normal and Millisecond Pulsars
• 3.4 The Population of Neutron Star Binaries
• 3.5 Going further

Binary and Millisecond Pulsars D. R. Lorimer (dunc@mpifr-bonn.mpg.de) http://www.livingreviews.org/lrr-1998-10 © Max-Planck-Gesellschaft. ISSN 1433-8351 Problems/Comments to livrev@aei-potsdam.mpg.de