Photoionization by attosecond (as) extreme ultraviolet (xuv) pulses into the
laser-dressed continuum of the ionized atom is commonly described in
strong-field approximation (SFA), neglecting the Coulomb interaction between
the emitted photoelectron (PE) and residual ion. By solving the time-dependent
Sch\"{o}dinger equation (TDSE), we identify a temporal shift δτ in
streaked PE spectra, which becomes significant at small PE energies. Within an
eikonal approximation, we trace this shift to the combined action of Coulomb
and laser forces on the released PE, suggesting the experimental and
theoretical scrutiny of their coupling in streaked PE spectra. The initial
state polarization effect by the laser pulse on the xuv streaked spectrum is
also examined.Comment: 9 pages, Accepted by Phys. Rev.