We present the results of a 50 ks long Chandra observation of the dipping
source XB 1916-053. During the observation two X-ray bursts occurred and the
dips were not present at each orbital period. From the zero-order image we
estimate the precise X-ray coordinates of the source with a 90% uncertainty of
0.6''. In this work we focus on the spectral study of discrete absorption
features, during the persistent emission, using the High Energy Transmission
Grating Spectrometer on board the Chandra satellite. We detect, for the first
time in the 1st-order spectra of XB 1916-053, absorption lines associated to Ne
X, Mg XII, Si XIV, and S XVI, and confirm the presence of the Fe XXV and Fe
XXVI absorption lines with a larger accuracy with respect to the previous XMM
EPIC pn observation. Assuming that the line widths are due to a bulk motion or
a turbulence associated to the coronal activity, we estimate that the lines are
produced in a photoionized absorber distant from the neutron star 4 x 10^{10}
cm, near the disk edge.Comment: 20 pages, 10 figures, submitted to ApJ on 2005-09-22, accepted by ApJ
on 2006-05-0