  We report on the temperature dependence of $^{63}$Cu and $^{199}$Hg NMR
magnetic shifts and linewidths for an optimally doped and an underdoped
HgBa$_{2}$CuO$_{4+\delta}$ single crystal, as well as the quadrupole splitting
and its distribution for $^{63}$Cu. From the $^{63}$Cu and $^{199}$Hg
\textit{magnetic shifts} we have recently concluded on the existence of two
spin components with different temperature dependencies [J. Haase, D. Rybicki,
C. P. Slichter, M. Greven, G. Yu, Y. Li, and X. Zhao, Phys. Rev. B 85, 104517
(2012)]. Here we give a comprehensive account of all data and focus on the
linewidths and quadrupole splittings. While the $^{63}$Cu quadrupole coupling
and its distribution are by and large temperature independent, we identify
three regions in temperature for which the magnetic widths differ
significantly: at the lowest temperatures the magnetic linewidths are dominated
by the rigid fluxoid lattice that seems to have disappeared above about 60 K.
In the intermediate temperature region, starting above 60 K, the magnetic
linewidth is dominated by the spatial distribution of the magnetic shift due to
the pseudogap spin component, and grows linearly with the total shift up to
about \textit{$\sim$}170-230 K, depending on sample and nucleus. Above this
temperature the third region begins with an sudden narrowing where the second,
Fermi-liquid-like spin component becomes homogeneous. We show that all
linewidths, quadrupolar as well as magnetic, above the fluxoid dominated region
can be understood with a simple model that assumes a coherent charge density
variation with concomitant variations of the two spin components. In addition,
we find a temperature independent spin based broadening in both samples that is
incoherent with the other broadening for the underdoped crystal, but becomes
coherent for the optimally doped crystal.
