37 research outputs found
Observing the launch of an Eddington wind in the luminous Seyfert galaxy PG1211+143
The luminous narrow line Seyfert galaxy PG1211+143 was the first non-BAL AGN
to reveal a powerful ionized wind, based on early observations with ESA's XMM
X-ray Observatory. Subsequent observations, mainly with XMM and the Japanese
SUZAKU Observatory, found such winds to be a common feature of luminous AGN.
Typical outflow velocities of v c and flow momenta are consistent with winds being launched by continuum driving from a
disc when the local mass accretion rate is super-Eddington. Here we report the
launch of a new, ultra-fast outflow component in PG1211+143, near the end of a
5-week XMM observing campaign, and discuss its origin in an ultra-fast {\it
inflow} of similar velocity detected some 3 weeks earlier. We find that the
inflow lasted for at least 3 days and delivered some 10 Earth mass of fresh
material into the innermost region of the source. While this mass by itself is
insufficient to cause a complete inner disc restructuring, we show that it is
sufficient to disrupt the X-ray emitting corona of the disc. We conclude that
it is this coronal re-arrangement of the inner tens gravitational radii in
PG1211+143 that subsequently caused the launch of a new wind.Comment: submitted to MNRA
Imprints of a high velocity wind on the soft x-ray spectrum of PG 1211+143
An extended XMM-Newton observation of the luminous narrow line Seyfert galaxy
PG 1211+143 in 2014 has revealed a more complex high velocity wind, with
components distinguished in velocity, ionization level, and column density.
Here we report soft x-ray emission and absorption features from the ionized
outflow, finding counterparts of both high velocity components, v ~ 0.129c and
v ~ 0.066c, recently identified in the highly ionized Fe K absorption spectrum.
The lower ionization of the co-moving soft x-ray absorbers imply a distribution
of higher density clouds embedded in the main outflow, while much higher column
densities for the same flow component in the hard x-ray spectra suggest
differing sight lines to the continuum x-ray source.Comment: 8 pages, 5 figures, 4 tables; Accepted for publication in MNRA
X-ray Spectral Variability and Rapid Variability of the Soft X-ray Spectrum Seyfert 1 Galaxies Ark 564 and Ton S180
The bright, soft X-ray spectrum Seyfert 1 galaxies Ark 564 and Ton S180 were
monitored for 35 days and 12 days with ASCA and RXTE (and EUVE for Ton S180).
The short time scale (hours-days) variability patterns were very similar across
energy bands, with no evidence of lags between any of the energy bands studied.
The fractional variability amplitude was almost independent of energy band. It
is difficult to simultaneously explain soft Seyferts stronger variability,
softer spectra, and weaker energy-dependence of the variability relative to
hard Seyferts. The soft and hard band light curves diverged on the longest time
scales probed, consistent with the fluctuation power density spectra that
showed relatively greater power on long time scales in the softest bands. The
simplest explanation is that a relatively hard, rapidly-variable component
dominates the total X-ray spectrum and a slowly-variable soft excess is present
in the lowest energy channels of ASCA. Although it would be natural to identify
the latter with an accretion disk and the former with a corona surrounding it,
a standard thin disk could not get hot enough to radiate significantly in the
ASCA band, and the observed variability time scales are much too short. The
hard component may have a more complex shape than a pure power-law. The most
rapid factor of 2 flares and dips occurred within ~1000 sec in Ark 564 and a
bit more slowly in Ton S180. The speed of the luminosity changes rules out
viscous or thermal processes and limits the size of the individual emission
regions to <~15 Schwarzschild radii (and probably much less), that is, to
either the inner disk or small regions in a corona
X-ray Power Density Spectrum of the Narrow Line Seyfert 1 Galaxy Akn 564
Beginning in 1999 January, the bright, strongly variable Narrow-Line Seyfert
1 (NLS1) galaxy Akn 564 has been observed by RXTE once every ~4.3 days. It was
also monitored every ~3.2 hr throughout 2000 July. These evenly-sampled
observations have allowed the first quantitative comparison of long and short
time-scale X-ray variability in an NLS1 and the derivation of an X-ray Power
Density Spectrum (PDS). The variability amplitude in the short time-scale light
curve is very similar to that in the long time-scale light curve, in marked
contrast to the stronger variability on longer time-scales which is
characteristic of "normal" broad-line Seyfert 1s (BLS1s). Furthermore, the Akn
564 PDS power law cuts off at a frequency of 8.7x10^-7 Hz corresponding to a
timescale of ~13 d, significantly shorter than that seen in the PDS of NGC
3516, a BLS1 of comparable luminosity.
This result is consistent with NLS1s showing faster (as opposed to larger
amplitude) variations than BLS1s, providing further evidence that NLS1s harbour
lower mass black holes than BLS1s of similar luminosity, accreting at a
correspondingly higher relative rate.Comment: Accepted for publication in Ap