A B S T R A C TWe present contemporary optical and infrared spectroscopic observations of the type IIn SN 1998S covering the period between 3 and 127 days after discovery. During the first week the spectra are characterized by prominent broad H, He and C iiiaN iii emission lines with narrow peaks, superimposed on a very blue continuum T , 24 000 KX In the following two weeks the C iiiaN iii emission vanished, together with the broad emission components of the H and He lines. Broad, blueshifted absorption components appeared in the spectra. The temperature of the continuum also dropped to ,14 000 K. By the end of the first month the spectrum comprised broad, blueshifted absorptions in H, He, Si ii, Fe ii and Sc ii. By day 44, broad emission components in H and He reappeared in the spectra. These persisted to as late as days ,100±130Y becoming increasingly asymmetric. We agree with Leonard et al. that the broad emission lines indicate interaction between the ejecta and circumstellar material (CSM) emitted by the progenitor. We also agree that the progenitor of SN 1998S appears to have gone through at least two phases of mass-loss, giving rise to two CSM zones. Examination of the spectra indicates that the inner zone extended to #90 au, while the outer CSM extended from 185 au to over 1800 au.We also present high-resolution spectra obtained at days 17 and 36. These spectra exhibit narrow P Cygni H i and He i lines superimposed on shallower, broader absorption components. Narrow lines of [N ii], [O iii], [Ne iii] and [Fe iii] are also seen. We attribute the narrow lines to recombination and heating following ionization of the outer CSM shell by the UV/X-ray flash at shock breakout. Using these lines, we show that the outer CSM had a velocity of 40±50 km s 21 X Assuming a constant velocity, we can infer that the outer CSM wind commenced more than 170 years ago, and ceased about 20 years ago, while the inner CSM wind may have commenced less than 9 years ago. During the era of the outer CSM wind the outflow from the progenitor was high ± at least ,2 Â 10 25 M ( yr 21 X This corresponds to a mass-loss of at least ,0.003 M ( , suggesting a massive progenitor. The shallower, broader absorption is of width ,350 km s 21 , and may have arisen from a component of the outer CSM shell produced when the progenitor was going through a later q 2001 RAS

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We report on the first spectrum up to 10 keV of the bright narrow-line Seyfert 1 galaxy Ton S 180, obtained with the imaging instruments onboard BeppoSAX. This is the first observed source in a sample of a dozen narrow-line Seyfert 1 galaxies in the BeppoSAX Core Program. We also present and discuss a high quality optical spectrum taken at the 1.5 m telescope at La Silla two months before the BeppoSAX observation.The X-ray spectrum shows a clear hardening above about 2 keV, where a power law with Γ ≃ 2.3 plus an iron line provide a good description of the data. This slope is significantly steeper than the typical one for classical Seyfert 1's and quasars. The best fit line energy is suggestive of highly ionized iron, which would support the idea that the high accretion rate is (one of) the fundamental parameter(s) characterizing the Narrow Line Seyfert 1 phenomenon.

We present measurements of the optical and X-ray continua of 108 AGN (Seyfert 1s and quasars) from the Rosat International X-ray/Optical Survey (RIXOS). The sample covers a wide range in redshift (0 < z < 3.3), in X-ray spectral slope (-1.5<α x <2.6) and in optical-to-X-ray ratio (0.4<α ox <1.5). A correlation is found between α x and α ox ; similar correlations have recently been reported in other X-ray and optical samples. We also identify previously unreported relationships between the optical slope (α opt ) and α x (particularly at high redshifts) and between α opt and α ox . These trends show that the overall optical-to-X-ray continuum changes from convex to concave as α x hardens, demonstrating a strong behavioural link between the optical/UV big blue bump (BBB) and the soft X-ray excess, which is consistent with them being part of the same spectral component.By constructing models of the optical-to-X-ray continuum, we demonstrate that the observed correlations are consistent with an intrinsic spectrum which is absorbed through different amounts of cold gas and dust. The intrinsic spectrum is the sum of an optical-to-soft X-ray 'big bump' component and an α x =1 power law; the column density of the cold gas ranges from 0 to ∼ 4 × 10 21 cm −2 and the dust-to-gas ratio is assumed to be Galactic. The 'big bump' may be represented by a T brem ∼ 10 6 K thermal bremsstrahlung or an accretion disk with a surrounding hot corona. The scatter in the data can accommodate a wide range in big bump temperature (or black hole mass) and strength. A source for the absorbing gas may be the dusty, molecular torus which lies beyond the broad line-emitting regions, although with a much lower column density than observed in Seyfert 2 galaxies. Alternatively, it may be the bulge of a spiral host galaxy or an elliptical host galaxy.