Relationship Between Scattering and Dispersion Measure of the Crab Nebula Pulsar

A strong correlation between scattering and the dispersion measure of the Crab Nebula pulsar B0531+21 has been confirmed through independent measurements from multiple observatories. The study reveals that scattering, ranging from 10 to 115 milliseconds, is caused by plasma clouds in the nebula with sizes between 10^11 and 10^12 meters, electron densities of 10^3 to 10^4 cm^-3, and varying turbulence levels. During a quiescent period (2002–2007), the turbulence coefficient was C²ₙ = 0.00661 m^-7, with mean density variations of Δnₑ ~ 0.02 cm^-3, while in an active phase (2009–2013), turbulence increased to C²ₙ = 0.0662 m^-7 and density fluctuations rose to Δnₑ ~ 0.06 cm^-3. These findings provide insights into the dynamic conditions of the nebula's plasma environment, offering a deeper understanding of pulsar scattering mechanisms.

Losovsky, B. Ya., Dumsky, D. V., & Belyatsky, Yu. A. (2019). Relationship Between Scattering and Dispersion Measure of the Crab Nebula Pulsar. Astronomy Reports, 63(10), 830–834. https://doi.org/10.1134/s1063772919090051