Astrophysics and Space Science (ISSN 0004-640X), vol. 132, no. 2, April 1987, p. 307-312.
Buitrago, J.; Atrio, F.
The present examination of general relativistic effect on the lag time between continuum and emission line variations in the broad line notes that in the case where the primary source region lies within the range of a strong gravitational field, simultaneity surfaces in the ionized gas are different from those obtained without accounting for the field. The determination of distances on the basis of light travel from the ionizing source to the gas clouds is found to depend on the primary emission region's gravitational field intensity. It is noted that if the primary radiation is located very near 2GM/c-squared, the light travel-time argument for the determination of distances leads to an overestimation in the size of the surrounding region.