(abridged) We present and discuss our observations of the NL quasar
PG1404+226 with ASCA and HST, and a re-analysis of our earlier observations
with ROSAT. The soft X-ray spectrum is very steep and displays an absorption
feature (edge or line at ~1.1 keV). We have applied a variety of models to the
ASCA and ROSAT spectra without finding a completely satisfactory fit, and the
identification of the edge remains uncertain. A satisfactory fit of the ASCA
spectrum assuming that the edge is produced by highly ionized iron (using the
code absori in XSPEC) is obtained with an overabundance of iron by a factor >
25 compared to solar, a suggestion supported by the extremely high equivalent
width of the Fe K_alpha line at 6.4 keV. A warm absorber model fitting the
absorption feature with NeVII-NeX edges and assuming a peculiar oxygen/neon
abundance ratio is consistent with the ROSAT data but not the ASCA data.
Finally, it is also possible that the observed edge is caused by a OVIII or
OVII edge or line, blueshifted by z_abs=0.2 to 0.5 depending on the specific
identification, as has been suggested previously for 2 other NL quasars, but
there are no other features in the UV and X-ray spectra in support of this
suggestion. Two systems of UV absorption lines, one nearly at rest in the
source frame, the other blueshifted by ~1900 km/s are identified in the HST/FOS
spectra.
Photoionization models indicate that the UV absorption and the ~1 keV
absorption are probably caused by absorbers with different physical conditions.
PG1404+226 is one more case of AGN where both UV and X-ray absorption features
are detected, thereby increasing further the significance of the previously
noted statistical association of the two types of absorbers.Comment: 11 pages, A&A in pres
