  We construct a map of the time derivative of the gravitational potential
traced by SDSS Luminous Red Galaxies. The potential decays on large scales due
to cosmic acceleration, leaving an imprint on cosmic microwave background (CMB)
radiation through the integrated Sachs-Wolfe (ISW) effect. With a template fit,
we directly measure this signature on the CMB at a 2-sigma confidence level.
The measurement is consistent with the cross-correlation statistic,
strengthening the claim that dark energy is indeed the cause of the
correlation. This new approach potentially simplifies the cosmological
interpretation. Our constructed linear ISW map shows no evidence for
degree-scale cold and hot spots associated with supervoid and supercluster
structures. This suggests that the linear ISW effect in a concordance
Lambda-CDM cosmology is insufficient to explain the strong CMB imprints from
these structures that we previously reported.
