Since the discovery of the first broad iron-K line in 1995 from the Seyfert Galaxy MCG-6-30-15 1 , broad iron-K lines have been found in several other Seyfert galaxies 2 , from accreting stellar mass black holes 3 and even from accreting neutron stars 4 . The iron-K line is prominent in the reflection spectrum 5,6 created by the hard X-ray continuum irradiating dense accreting matter. Relativistic distortion 7 of the line makes it sensitive to the strong gravity and spin of the black hole 8 . The accompanying iron-L line emission should be detectable when the iron abundance is high. Here we report the first discovery of both iron-K and L emission, using XMM-Newton observations of the Narrow-1

An intrinsically narrow line emitted by an accretion disk around a black hole appears broadened and skewed as a result of the Doppler e †ect and gravitational redshift. The Ñuorescent iron line in the X-ray band at 6.4È6.9 keV is the strongest such line and is seen in the X-ray spectrum of many active galactic nuclei and, in particular, Seyfert galaxies. It is an important diagnostic with which to study the geometry and other properties of the accretion Ñow very close to the central black hole. The broad iron line indicates the presence of a standard thin accretion disk in those objects, often seen at low inclination. The broad iron line has opened up strong gravitational e †ects around black holes to observational study with wide-reaching consequences for both astrophysics and physics.

We present the first results from a 325‐ks observation of the Seyfert 1 galaxy MCG–6‐30‐15 with XMM‐Newton and BeppoSAX. The strong, broad, skewed iron line is clearly detected and is well characterized by a steep emissivity profile within 6rg (i.e. 6GM/c2) and a flatter profile beyond. The inner radius of the emission appears to lie at about 2rg, consistent with results reported from both an earlier XMM‐Newton observation of MCG–6‐30‐15 by Wilms et al. and part of an ASCA observation by Iwasawa et al. when the source was in a lower flux state. The radius and steep emissivity profile do depend however on an assumed incident power‐law continuum and a lack of complex absorption above 2.5 keV. The blue wing of the line profile is indented, either by absorption at about 6.7 keV or by a hydrogenic iron emission line. The broad iron line flux does not follow the continuum variations in a simple manner.

We report X-ray observations of the nearby, powerful radio galaxy Pictor A with the Chandra Observatory and optical and near uv observations of its western radio hot spot with the Hubble Space Telescope. X-ray emission is detected from the nucleus, a 1. ′ 9 (110 kpc) long jet to the west of the nucleus, the western radio hot spot some 4. ′ 2 (240 kpc) from the nucleus, and the eastern radio lobe. The morphology of the western hot spot is remarkably similar to that seen at radio and optical wavelengths, where the emission is known to be synchrotron radiation. The X-ray spectrum of the hot spot is well described by an absorbed power law with photon index Γ = 2.07 ± 0.11. The X-ray jet coincides with a weak radio jet and is laterally extended by ≃ 2. ′′ 0 (1.9 kpc). The observed jet is up to ≃ 15 times brighter in X-rays than any counter jet, a difference ascribed to relativistic boosting as the western radio lobe is probably the closer. The jet's spectrum is well modelled by an absorbed power law with Γ = 1.94 +0.43 −0.49 and poorly fitted by a Raymond-Smith thermal plasma model.The emission processes responsible for the X-rays are discussed in detail. The radio-optical spectrum of the hot spot breaks or turns down at 10 13−14 Hz, and its X-ray spectrum is not a simple extension of the radio-optical spectrum to higher frequencies. Thermal models for the hot spot's X-ray emission are ruled out. Synchrotron self-Compton models involving scattering from the known population of electrons give the wrong spectral index for the hot spot's X-ray emission and are also excluded. A composite synchrotron plus synchrotron self-Compton model can match the X-ray observations but requires similar contributions from the two components in the Chandra band. We show that the hot spot's X-ray emission could be synchrotron self-Compton emission from a hitherto unobserved population of electrons emitting at low radio frequencies, but do not favor this model in view of the very weak magnetic field required.An inverse Compton model of the jet, in which it scatters microwave background photons but moves non-relativistically, requires a magnetic field a factor of ≃ 30 below equipartition, and ad hoc conditions to explain why the radio lobes are fainter than the jet in X-rays but brighter in the radio. These problems are alleviated if the jet moves relativistically, but models with an equipartition field require an implausibly small angle (θ) between the jet and the line of sight. A model with θ ≃ 23 • and a field a factor of 6 below equipartition seems viable.Synchrotron radiation is an alternative process for the X-ray emission. The expected synchrotron spectrum from relativistic electrons accelerated by strong shocks and subject to synchrotron radiation losses is in very good agreement with that observed for both the hot spot and jet. The possibility that the relativistic electrons result via photo-pion production by high energy protons accelerated in shocks (a 'proton induced cascade') is briefly discussed.

We report sub arc-second resolution X-ray imaging-spectroscopy of the archetypal type 2 Seyfert galaxy NGC 1068 with the Chandra X-ray Observatory. The observations reveal the detailed structure and spectra of the 13 kpc-extent nebulosity previously imaged at lower resolution with ROSAT. The Chandra image shows a bright, compact source coincident with the brightest radio and optical emission; this source is extended by ≃ 1. ′′ 5 (165 pc) in the same direction as the nuclear optical line and radio continuum emission. Bright X-ray emission extends ≃ 5 ′′ (550 pc) to the NE and coincides with the NE radio lobe and gas in the narrow line region. The large-scale emission shows trailing spiral arms and other structures. Numerous point sources associated with NGC 1068 are seen. There is a very strong correlation between the X-ray emission and the high excitation ionized gas seen in HST and ground-based [O iii] λ5007 images. The X-rays to the NE of the nucleus are absorbed by only the Galactic column density and thus originate from the near side of the disk of NGC 1068. In contrast the X-rays to the SW are more highly absorbed and must come from gas in the disk or on the far side of it. This geometry is similar to that inferred for the narrow line region and radio lobes.Spectra have been obtained for the nucleus, the bright region ≃ 4 ′′ to the NE and 8 areas in the extended emission. The spectra are inconsistent with hot plasma models, the best approximations requiring implausibly low abundances ( ∼ < 0.1Z ⊙ ). Models involving two smooth continua (either a bremsstrahlung plus a power-law or two bremsstrahlungs) plus emission lines provide excellent descriptions of the spectra. The emission lines cannot be uniquely identified with the present spectral resolution (∼ 110 -190 eV), but are consistent with the brighter lines seen in the XMM-Newton RGS spectrum below 2 keV. Hard X-ray (above 2 keV) emission, including an iron line, is seen extending ≃ 20 ′′ (2.2 kpc) NE and SW of the nucleus. Lower surface brightness, hard X-ray emission, with a tentatively detected iron line extends 50 ′′ (5.5 kpc) to the west and south. Our results, when taken together with the XMM-Newton RGS spectrum, suggest photoionization and fluorescence of gas by radiation from the Seyfert nucleus to several kpc from it. The facts that i) the large scale (arc minute) and small scale (few arc secs) X-ray emissions align well and ii) the morphology of the large-scale emission does not correlate well with the starburst suggests that the starburst is not the dominant source of the extended X-rays.

We present numerical simulations investigating the interaction of active galactic nucleus jets with galaxy clusters, for the first time taking into account the dynamic nature of the cluster gas and detailed cluster physics. The simulations successfully reproduce the observed morphologies of radio sources in clusters. We find that cluster inhomogeneities and large‐scale flows have a significant impact on the morphology of the radio source and cannot be ignored a priori when investigating radio source dynamics. Morphological comparison suggests that the gas in the centres of clusters like Virgo and Abell 4059 shows significant shear and/or rotation. We find that shear and rotation in the intracluster medium move large amounts of cold material back into the path of the jet, ensuring that subsequent jet outbursts encounter a sufficient column density of gas to couple with the inner cluster gas, thus alleviating the problem of evacuated channels discussed in the recent literature. The same effects redistribute the excess energy ΔE deposited by the jet, making the distribution of ΔE at late times consistent with being isotropic.

We measure X‐ray emission from the outskirts of the cluster of galaxies PKS 0745−191 with Suzaku, determining radial profiles of density, temperature, entropy, gas fraction and mass. These measurements extend beyond the virial radius for the first time, providing new information about cluster assembly and the diffuse intracluster medium out to ∼1.5 r200(r200≃ 1.7 Mpc ≃ 15 arcmin). The temperature is found to decrease by roughly 70 per cent from 0.3 to 1r200. We also see a flattening of the entropy profile near the virial radius and consider the implications this has for the assumption of hydrostatic equilibrium when deriving mass estimates. We place these observations in the context of simulations and analytical models to develop a better understanding of non‐gravitational physics in the outskirts of the cluster.

We present the results of a broadband simultaneous campaign on the nearby low-luminosity active galactic nucleus M81*. From February through August 2005, we observed M81* five times using the Chandra X-ray Observatory with the High-Energy Transmission Grating Spectrometer, complemented by groundbased observations with the Giant Meterwave Radio Telescope, the Very Large Array and Very Large Baseline Array, the Plateau de Bure Interferometer at IRAM, the Submillimeter Array and Lick Observatory. We discuss how the resulting spectra vary over short and longer timescales compared to previous results, especially in the X-rays where this is the first ever longer-term campaign at spatial resolution high enough to nearly isolate the nucleus (17pc). We compare the spectrum to our Galactic center weakly active nucleus Sgr A*, which has undergone similar campaigns, as well as to weakly accreting X-ray binaries in the context of outflow-dominated models. In agreement with recent results suggesting that the physics of weakly-accreting black holes scales predictably with mass, we find that the exact same model which successfully describes hard state X-ray binaries applies to M81*, with very similar physical parameters.