Space Telescope and Optical Reverberation Mapping Project. XIII. An Atlas of UV and X-ray Spectroscopic Signatures of theDisk Wind in NGC 5548

TL;DR

This study presents an atlas of UV and X-ray spectral signatures of disk winds in NGC 5548, revealing how different wind types influence AGN spectral lines and impact black hole measurements.

Contribution

It introduces a photoionization model atlas for various disk-winds, elucidating their effects on AGN spectra and aiding future reverberation mapping studies.

Findings

Three types of disk-winds identified with distinct ionization properties

Winds significantly affect spectral line features and black hole mass estimates

Most AGNs likely host transparent, fully ionized winds with minimal spectral impact

Abstract

The unusual behavior of the spectral lines of NGC5548 during the STORM campaign demonstrated a missing piece in the structure of AGNs. For a two-month period in the middle of the campaign, the spectral lines showed a deficit in flux and a reduced response to the variations of the UV continuum. This was the first time that this behavior was unequivocally observed in an AGN. Our previous papers explained this as being due to a variable disk-wind which acts as a shield and alters the SED. Here we use Cloudy to create an atlas of photoionization models for a variety of disk-winds to study their effects on the SED. We show that the winds have three different cases: Case 1 winds are transparent, fully ionized and have minimal effects on the intrinsic SED, although they can produce some line emission, especially HeIIor FeK{\alpha}. We propose that this is the situation in most of the AGNs. Case 2 winds have a He++-He+ionization-front, block part of the XUV continuum but transmit much of the Lyman continuum. They lead to the observed abnormal behavior. Case 3 winds have H+ionization-front and block much of the Lyman continuum. The results show that the presence of the winds has important effects on the spectral lines of AGNs. They will thus have an effect on the measurements of the black hole mass and the geometry of the AGN. This atlas of spectral simulations can serve as a guide to future reverberation campaigns