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Register a new userVariable blurred reflection in the narrow-line Seyfert 1 galaxy Mrk 493
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K. Bonson
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We examine a 200 ks XMM-Newton observation of the narrow-line Seyfert 1 galaxy Mrk 493. The active galaxy was half as bright as in a previous 2003 snapshot observation and the current lower flux enables a study of the putative reflection component in detail. We determine the characteristics of the 2015 X-ray continuum by first analyzing the short-term variability using model-independent techniques. We then continue with a time-resolve analysis including spectral fitting and modelling the fractional variability. We determine that the variability arises from changes in the amount of primary flux striking the accretion disk, which induces changes in the ionization parameter and flux of the blurred reflection component. The observations seem consistent with the picture that the primary source is of roughly constant brightness and that variations arise from changes in the degree of light bending happening in the vicinity of the supermassive black hole.
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Mrk 1388 has an unusual Seyfert nucleus that shows narrow emission-line components without broad ones, but shows a strong featureless continuum and strong iron-forbidden high-ionization emission lines. The apparent coexistence of type-1/2 characteristics is potentially attributed to a heavily obscured broad-line region or to an intermediate-mass black hole with a broad-line component intrinsically narrower than those of typical narrow-line Seyfert 1 (NLS1) galaxies. Our observation using very-long-baseline interferometry (VLBI) reveals high-brightness radio emission from nonthermal jets from an active galactic nucleus (AGN) with a significant radio luminosity. Furthermore, we investigate the radial profile of the host galaxy using a Hubble Space Telescope (HST) image, which shows a Sersic index suggestive of a pseudobulge. Using the VLBI and HST results, which are essentially not affected by dust extinction, three individual methods provide similar estimates for the black hole mass: (0.76--5.4)x10^6 M_sun, 1.5x10^6 M_sun, and 4.1x10^6 M_sun. These masses are in a range that is preferential for typical NLS1 galaxies rather than for intermediate-mass black holes. Based on the estimated masses, the full width at half maximum $FWHM(H_beta)$ of approximately 1200--1700 km/s should have been seen. The scenario of a heavily absorbed NLS1 nucleus can explain the peculiarities previously observed.
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Relativistically blueshifted absorption features of highly ionised ions, the so-called ultra-fast outflows (UFOs), have been detected in the X-ray spectra of a number of accreting supermassive black holes. If these features truly originate from accretion disc winds accelerated to more than 10 per cent of the speed of light, their energy budget is very significant and they can contribute to or even drive galaxy-scale feedback from active galactic nuclei (AGN). However, the UFO spectral features are often weak due to high ionisation of the outflowing material, and the inference of the wind physical properties can be complicated by other spectral features in AGN such as relativistic reflection. Here we study a highly accreting Narrow Line Seyfert 1 galaxy PG 1448+273. We apply an automated, systematic routine for detecting outflows in accreting systems and achieve an unambiguous detection of a UFO in this AGN. The UFO absorption is observed in both soft and hard X-ray bands with the XMM-Newton observatory. The velocity of the outflow is (26900 +- 600) km/s (~0.09c), with an ionisation parameter of log ({xi} / erg cm s^-1)=4.03_{-0.08}^{+0.10} and a column density above 10^23 cm^-2. At the same time, we detect weak warm absorption features in the spectrum of the object. Our systematic outflow search suggests the presence of further multi-phase wind structure, but we cannot claim a significant detection considering the present data quality. The UFO is not detected in a second, shorter observation with XMM-Newton, indicating variability in time, observed also in other similar AGN.
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