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

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 ∼1017–1018 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 2M yr−1 , close to the Eddington rate for PG 1211+143 and similar to that previously deduced from the Fe K absorption

TESTING RELATIVISTIC REFLECTION AND RESOLVING OUTFLOWS IN PG 1211+143 WITH XMM-NEWTON AND NuSTAR

We analyze the broad-band X-ray spectrum (0.3–50 keV) of the luminous Seyfert 1/quasar PG 1211+143—the archetypal source for high-velocity X-ray outflows—using near-simultaneous XMM-Newton and NuSTAR observations. We compare pure relativistic reflection models with a model including the strong imprint of photoionized emission and absorption from a high-velocity wind, finding a spectral fit that extrapolates well over the higher photon energies covered by NuSTAR. Inclusion of the high signal-to-noise ratio XMM-Newton spectrum provides much tighter constraints on the model parameters, with a much harder photon index/lower reflection fraction compared to that from the NuSTAR data alone. We show that pure relativistic reflection models are not able to account for the spectral complexity of PG 1211+143 and that wind absorption models are strongly required to match the data in both the soft X-ray and Fe K spectral regions. In confirming the significance of previously reported ionized absorption features, the new analysis provides a further demonstration of the power of combining the high throughput and resolution of long-look XMM-Newton observations with the unprecedented spectral coverage of NuSTAR

X-ray timing analysis of the quasar PG 1211+143

We report on a timing analysis of a new ∼630 ks XMM–Newton observation of the quasar, PG 1211+143. We find a well-defined X-ray power spectrum with a well-detected bend at ∼7 × 10−5 Hz, consistent with the established tbend–MBH correlation for luminous, accreting black holes. We find the linear rms–flux relation commonly observed in accreting black hole systems and investigate the energy-dependence of the rms. The fractional rms is roughly constant with energy on short time-scales (<1 d; within observations) whereas there is enhanced soft band variability on long time-scales (between observations typically spaced by a few days). Additionally, we also report on the optical–UV variability using the Optical Monitor on-board XMM–Newton and a ∼2-month-long overlapping monitoring programme with Swift. We find that, although there is little UV variability within observations (<1 d), UV variations of a few per cent exist on time-scales of ∼days–weeks

A deep XMM-Newton observation of the ultraluminous X-ray source Holmberg II X-1: the case against a 1000 M solar black hole

We present results from a 112-ks long look by XMM-Newton at the ultraluminous X-ray source (ULX) Holmberg II X-1 (Ho II X-1), long thought to be the one of best candidates for the missing class of intermediate-mass black holes (IMBHs). Our data comprises the first high-quality XMM-Newton/RGS (reflection grating spectrometer) spectrum of an ULX, and an XMM-Newton/EPIC (European Photo Imaging Camera) spectrum with unprecedented signal-to-noise ratio. A detailed timing analysis shows that any variability on time-scales of minutes to hours is very weak (less than a few per cent fractional rms), though larger amplitude variations on much shorter time-scales could be hidden by photon counting statistics. This result suggests that if Ho II X-1 harbours an IMBH, then we are observing this source in a highly unusual and atypical state when compared with the known variability behaviour of other accreting systems of large mass. Moreover, unlike galactic X-ray binaries, our spectral analysis indicates the possible presence of an optically thick low-temperature corona. Taken together our timing and spectral analysis suggests that the compact companion is most likely a high-luminosity analogue of black hole binary systems similar to GRS 1915+105, the galactic microquasar, harbouring a compact object of mass no greater than 100 M⊙

An X-ray Baldwin effect for the narrow Fe Kα lines observed in active galactic nuclei

The majority of active galactic nuclei (AGN) observed by XMM–Newton reveal narrow Fe Kα lines at ∼6.4 keV, due to emission from cold (neutral) material. There is an X-ray Baldwin effect in type I AGN, in that the equivalent width (EW) of the line decreases with increasing luminosity, with weighted linear regression giving EW∝ L[superscript −0.17±0.08] (Spearman Rank probability of >99.9 per cent).With current instrumental capabilities it is not possible to determine the precise origin for the narrow line, with both the broad-line region and putative molecular torus being possibilities. A possible explanation for the X-ray Baldwin effect is a decrease in the covering factor of the material forming the fluorescence line

XMM-Newton spectroscopy of high-redshift quasars

XMM–Newton observations of 29 high-redshift (z > 2) quasars, including seven radio-quiet, 16 radio-loud and six broad absorption line (BAL) objects, are presented; due to the high redshifts, the rest-frame energy bands extend up to ∼30–70 keV. Over 2–10 keV, the quasars can be well fitted in each case by a simple power law, with no strong evidence for iron emission lines. The lack of iron lines is in agreement both with dilution by the radio jet emission (for the radio-loud quasars) and the X-ray Baldwin effect. No Compton reflection humps at higher energies (i.e. above 10 keV in the rest frame) are detected either. Over the broad-band (0.3–10 keV), approximately half (nine out of 16) of the radio-loud quasars are intrinsically absorbed, with the values of N[subscript H] generally being 1 × 10²² to 2 × 10²² cm[superscript -]² in the rest frames of the objects. None of the seven radio-quiet objects shows excess absorption, while four of the six BAL quasars are absorbed. The radio-loud quasars have flatter continuum slopes than their radio-quiet counterparts (Γ[subscript RL] ∼ 1.55; Γ[subscript RQ] ∼ 1.98 over 2–10 keV), while, after modelling the absorption, the underlying photon index for the six BAL quasars is formally consistent with the non-BAL radio-quiet objects

Suzaku observations of a hard excess in 1H 0419-577: Detection of a Compton-thick partial-covering absorber

We present results from a 200 ks Suzaku observation of 1H 0419 – 577 taken during 2007 July. The source shows a strong excess of counts above 10 keV compared to the extrapolation of models based on previous data in the 0.5-10 keV band. The "hard excess" in 1H 0419 – 577 can be explained by the presence of a Compton-thick partial-covering absorber that covers ~70% of the source. The Compton-thick gas likely originates from a radius inside of the optical broad-line region and may form part of a clumpy disk wind. The fluorescent Fe Kα luminosity measured by Suzaku is consistent with that expected from an equatorial disk wind

Soft X-ray emission lines in the afterglow spectrum of GRB 011211: A detailed XMM-Newton analysis

We report on an XMM-Newton observation of the X-ray afterglow of the Gamma Ray Burst GRB 011211, originally detected by Beppo-SAX on 11th December 2001. The early afterglow spectrum obtained by XMM-Newton, observed 11 hours after the initial burst, appeared to reveal decaying H-like K $\alpha$ emission lines of Mg, Si, S, Ar and Ca, arising in enriched material with an outflow velocity of order 0.1c (Reeves et al. 2002). This was attributed to matter ejected from a massive stellar progenitor occurring shortly before the burst itself. Here, we present a detailed re-analysis of the XMM-Newton EPIC observations of GRB 011211. In particular, we show that the detection of the soft X-ray line emission appears robust, regardless of detector background, calibration, spectral binning, or the spectral model that is assumed. We demonstrate that thermal emission, from an optically thin plasma, is the most plausible model that can account for the soft X-ray emission, which appears to be the case for at least two burst afterglow spectra observed by XMM-Newton. The X-ray spectrum of GRB 011211 appears to evolve with time after the first 10 ks of the XMM-Newton observation as the Si and S emission lines are only detected during the first 10 ks of observation. The observations suggest that thermal emission is present during the early afterglow spectrum, whilst a power-law component dominates the latter stages. Finally we estimate the mass of the ejected material in GRB 011211 to be of the order 4-20 solar masses

Serendipitous active galactic nuclei in the XMM–Newton fields of Markarian 205 and QSO 0130−403

The X-ray spectra of serendipitously observed active galactic nuclei (AGN) in the XMM–Newton fields of Mrk 205 and QSO 0130−403 are analysed. The sample consists of 23 objects, none of which is detected at radio frequencies, with a median X-ray luminosity of ∼4 × 10[superscript 44] erg s[superscript −1] and redshifts ranging from ∼0.1 to just over 3. The mean photon index was found to be 1.89 ± 0.04. In contrast with past ASCA and ROSAT observations of high-redshift radio-loud quasars, we find little evidence for excess intrinsic absorption in these radio-quiet objects, with only three sources requiring a column density in excess of the Galactic value. Comparing the measured spectral indices over the redshift range, we also find there is no X-ray spectral evolution of quasi-stellar objects (QSOs) with time, up to redshift of 3. Within the sample there is no evidence for evolution of the optical to X-ray spectral index, α[subscript ox], with redshift, the mean value being −1.66 ± 0.04. However, upon comparing the values from the Bright Quasar Survey at low redshift (z 4), a slight steepening of αox is noted for the more distant objects. In most of the sources there is no significant requirement for a soft excess, although a weak thermal component (⩽ 10 per cent of L[subscript X]) cannot be excluded. There is an indication of spectral flattening (by ΔΓ = 0.2) at higher energies (>3 keV, QSO rest frame) for the sample as a whole. This is consistent with the presence of a Compton reflection component in these radio-quiet AGN, with the scattering medium (such as an accretion disc or molecular torus) occupying a solid angle of 2π sr to the X-ray source

The XMm Newton Iron Line Profile of NGC 3783

We report on observations of the iron K line in the nearby Seyfert 1 galaxy, NGC 3783, obtained in a long, two-orbit (~240 ks) XMM-Newton observation. The line profile obtained exhibits two strong narrow peaks at 6.4 and 7.0 keV, with measured line equivalent widths of 120 and 35 eV, respectively. The 6.4 keV emission is the Kα line from near neutral Fe, while the 7.0 keV feature probably originates from a blend of the neutral Fe Kβ line and the hydrogen-like line of Fe at 6.97 keV. The relatively narrow velocity width of the Kα line (lesssim5000 km s-1), its lack of response to the continuum emission on short timescales, and the detection of a neutral Compton reflection component are all consistent with a distant origin in Compton-thick matter such as the putative molecular torus. A strong absorption line from highly ionized iron (at 6.67 keV) is detected in the time-averaged iron line profile, while the depth of the feature appears to vary with time, being strongest when the continuum flux is higher. The iron absorption line probably arises from the highest ionization component of the known warm absorber in NGC 3783, with an ionization of log ξ ~ 3 and column density of NH ~ 5 × 10[Superscript: 22] cm[Superscript: -2] and may originate from within 0.1 pc of the nucleus. A weak red wing to the iron K line profile is also detected below 6.4 keV. However, when the effect of the highly ionized warm absorber on the underlying continuum is taken into account, the requirement for a relativistic iron line component from the inner disk is reduced