The Variable Fast Soft X-Ray Wind in PG 1211+143

Abstract

The analysis of a series of seven observations of the nearby (z = 0.0809) QSO PG 1211+143, taken with the Reflection Grating Spectrometer (RGS) onboard XMM-Newton in 2014, are presented. The high-resolution soft X-ray spectrum, with a total exposure exceeding 600 ks, shows a series of blueshifted absorption lines from the He and H-like transitions of N, O, and Ne, as well as from L-shell Fe. The strongest absorption lines are all systematically blueshifted by −0.06c, originating in two absorption zones from low-and high-ionization gas. Both zones are variable on timescales of days, with the variations in absorber opacity effectively explained by either column density changes or the absorber ionization responding directly to the continuum flux. We find that the soft X-ray absorbers probably exist in a two-phase wind at a radial distance of ∼10 17 -10 18 cm from the black hole with the lower-ionization gas as denser clumps embedded within a higher-ionization outflow. The overall mass outflow rate of the soft X-ray wind may be as high as M 2  yr −1 , close to the Eddington rate for PG 1211+143 and similar to that previously deduced from the Fe K absorption.

Resolving the X-Ray Obscuration in a Low-flux Observation of the Quasar PDS 456

“…A similar scenario was also recently suggested for the fast outflow in the quasar PG 1211+143 (Reeves et al 2018b). Here, the fast wind consists of a two phase (low and high ionization) clumpy medium, where the smaller, denser low ionization clumps may account for the rapid variations in the soft X-ray absorbing gas on timescales of days.…”

“…The nearby (z = 0.0809) non-BAL QSO PG 1211+143, which has a well established Xray ultra fast outflow (Pounds et al 2003;Pounds & Reeves 2009;Reeves et al 2018b), has recently been found to have a broad UV absorption trough, blueshifted with respect to Lyα by −17, 000 km s −1 (Kriss et al 2018a). This is consistent with the blue-shift (of −0.06c) of the soft X-ray absorber, as measured in contemporary X-ray grating observa-tions (Reeves et al 2018b;Danehkar et al 2018) with XMM-Newton RGS and Chandra HETG, as well as with the velocity at iron K (Pounds et al 2016). In PG 1211+143, the UV mini-BAL trough also appears to be variable and is not detected in all of the epochs analyzed by Kriss et al (2018a).…”

“…Indeed, from an analysis of the XMM-Newton Reflection Grating Spectrometer (RGS) observations of PDS 456, Reeves et al (2016) showed that the soft X-ray spectrum exhibits blue-shifted absorption troughs, which may arise from a lower ionization component of the wind. Recent observations of other AGN are now also revealing soft X-ray components of ultra fast outflows, implying that the wind structure may be more complex than a simple homogeneous outflow (Pounds et al 2003;Longinotti et al 2015;Reeves et al 2018b;Danehkar et al 2018;Pinto et al 2018).…”

The Ultra-fast Outflow of the Quasar PG 1211+143 as Viewed by Time-averaged Chandra Grating Spectroscopy

“…Reanalysis of this same data set reaffirmed the detection of ultra-high-velocity gas, but at −0.14±0.01c, with additional high-ionization lines at approximately −0.07c (Pounds 2014). Most recently, the deepest observations to date of PG 1211 +143 using XMM-Newton (∼450 ks) in 2014 again detected ultra-high-velocity gas at −0.129c and high-velocity gas at −0.066±0.003c (Pounds et al 2016b;Reeves et al 2018). The UFO at −0.129c is not seen in contemporaneous NuSTAR data (Zoghbi et al 2015), but a combined analysis of the XMMNewton and NuSTAR spectra show that the spectral structure around 7 keV is quite complex.…”

“…Subsequent analysis of the 2014 XMM-Newton RGS data by Reeves et al (2018) shows that two lower-ionization, lowervelocity absorbers are also present with velocities of −0.062± 0.001c (v out = −18,600 ± 300 km s ) and −0.059±0.002c (v out = −17,700 ± 600 km s −1 ), the latter of which is a good match to the −17,300 km s −1 (−0.0577c) warm absorber we detect in our Chandra spectrum. However, the absorber we detect is slightly lower in ionization (log x = -+ 2.87 0.10 0.32 versus log ξ=3.4±0.1), and nearly an order of magnitude lower in column density (N H = 3 × 10 21 cm −2 versus 1 × 10 22 cm −2…”