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We report the detection of high-amplitude X-ray flaring of the AGN HE 1136-2304, which is accompanied by a strong increase in the flux of the broad Balmer lines, changing its Seyfert type from almost type 2 in 1993 down to 1.5 in 2014. HE 1136-2304 was detected by the $\textit{XMM–Newton}$ slew survey at >10 times the flux it had in the $\textit{ROSAT}$ all-sky survey, and confirmed with $\textit{Swift}$ follow-up after increasing in X-ray flux by a factor of ~30. Optical spectroscopy with SALT shows that the AGN has changed from a Seyfert 1.95 to a Seyfert 1.5 galaxy, with greatly increased broad line emission and an increase in blue continuum AGN flux by a factor of >4. The X-ray spectra from $\textit{XMM–Newton}$ and $\textit{NuSTAR}$ reveal moderate intrinsic absorption and a high energy cutoff at ~100 keV. We consider several different physical scenarios for a flare, such as changes in obscuring material, tidal disruption events, and an increase in the accretion rate. We find that the most likely cause of the increased flux is an increase in the accretion rate, although it could also be due to a change in obscuration., MLP acknowledges financial support from the Science and Technology Facilities Council (STFC). This paper is based on observations taken with the SALT telescope. This work has been supported by DFG grant Ko 857/32-2. Based on observations with XMM–Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. This work made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). We would also like to thank Neil Gehrels for approving the Swift ToO requests, and the Swift science operation team for performing the observations.

Context. Icy grains in the inner coma of a comet may play an important role in the energy balance and in the production of certain gas coma species. Their existence has therefore been assumed repeatedly to explain a variety of observed phenomena. However, owing to their extremely short life time no evidence for the presence of icy grains had been found in any active comet close to the Sun. Aims. We observed Comet 9P/Tempel 1 during the Deep Impact mission to look for phenomena induced by the impact. Methods. The comet was observed with the XMM-Newton Observatory. We used the EPIC camera for X-ray imaging and the Optical Monitor for monitoring in the ultraviolet and visible spectral range. Results. An outburst of the comet nucleus was observed as a result of the impact and the evolution of the coma was monitored in gas and dust. Our observations led to the first detection of icy grains in a comet at 1.5 AU from the Sun. Conclusions. We showed for the first time that the material ejected from the nucleus of a comet contains icy grains, even at small heliocentric distance.

The large amplitude of the variations of the Seyfert I Galaxy Fairall-9 between 1978 and 1991 make this Active Galaxy especially suitable for a combined study in terms of reverberation analysis and photoioniza- tion modeling over the velocity eld of the broad lines of its ultraviolet spectrum. We have combined our ultravio- let data with those available at other wavelengths to de- rive the intrinsic ionizing continuum and to compare the predictions of the photoionization models with the obser- vations. The UV continuum varies with a factor of 33 4 on a characteristic time scale of 182 days. The intrinsic spectral index UV-optical is = 0:07 0:02 and the optical variations do not lag behind the UV variations at the mean sampling interval of 96 days. In the near IR, the J band flux presents a direct extension of the UV-optical continuum (J UV = 0:07 0:05). Only at low flux levels is the 2 10 keV flux proportional to the UV contin- uum, at higher UV flux levels proportionality between the X-rays and the UV brightness breaks down. The con- tinuum spectral energy distribution (SED) of the nu- cleus supports the previously reported FIR-NIR excess associated with 0.02 M dust at a distance of some 400 100 light-days, as well as a soft X-ray excess, possi- bly associated with the reprocessing on an accretion disk of the hard X-rays emitted from a region above the disk. The presence of strong Fe Kline in the GINGA spec- tra of this galaxy does lend support to this model. Line prole variability has been used to isolate four gaussian line components, which are sucient to describe all lines at all levels of brightness in a consistent way: one nar- row (i.e. unresolved at the IUE resolution), and three broad components: a central (velocity same as the nar

A detailed emission-line decomposition has been made from 15 years of observations with the IUE satellite of the highly variable Seyfert 1 galaxy Fairall 9, allowing us to study the line variability as a function of velocity and continuum brightness. The variability over the different velocity domains of the broad lines has been related to the continuum variability over a large wavelength domain from the X-rays to the infrared. Clear delays were established between the redshifted and blueshifted parts of the lines in Lyα and C IV, with the red sides of the lines responding faster with no delay and the blue sides responding with a delay of some 230 days. The observed spectral variability behavior of the continuum has been used as input for photoionization model calculations and the combined constraints from the models and differences for gas at different velocities define the structure and motions in the BLR.

We present a detailed analysis of all the X-ray data taken by the XMM-Newton satellite of a small sample of five Seyfert 1 galaxies: ESO 359-G19, HE 1143-1810, CTS A08.12, Mkn 110, and UGC 11763. Our aim is to characterize the different components of the material that print the absorption and emission features in the X-ray spectra of these objects. The continuum emission was studied through the EPIC spectra taking advantage of the spectral range of these cameras. The high resolution RGS spectra were analyzed in order to characterize the absorbing features and the emission line features that arise in the spectra of these sources., Facultad de Ciencias Astronómicas y Geofísicas

We have compiled multiwavelength data (in the radio, FIR, optical, UV and X-ray ranges) for a sample of 126 galaxies, including QSO, Seyfert 1, Seyfert 2 and galaxies dominated by star-forming processes. We have tested the implications of “unified Seyfert models”, which assume that Seyfert 1 and 2 galaxies are intrinsically the same kind of objects, but seen at different angles. A dense obscuring torus around the nucleus would originate the spectral differences actually observed. From our data we conclude that the UV-soft X-ray emission can not be seen through the torus. On the other hand, the occultation/reflection picture underestimates significantly the UV luminosity.

We present the data and initial results from a combined Hubble Space Telescope (HST)/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-1989. IUE spectra were obtained once every 2 days for a period of 74 days beginning on 1993 March 14. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both CCD imaging and aperture photometry), are reported for the period 1992 October-1993 September, although many of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution we describe the acquisition and reduction of all of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies.

Mid-infrared images of the Seyfert 1 galaxy Mrk 279 obtained with the ISO satellite are presented together with the results of a one-year monitoring campaign of the 2.5-11.7 micron spectrum. Contemporaneous optical photometric and spectrophotometric observations are also presented. The galaxy appears as a point-like source at the resolution of the ISOCAM instrument, 4-5". The 2.5-11.7 micron average spectrum of the nucleus in Mrk 279 shows a strong power law continuum with a spectral index alpha = -0.80+/-0.05 and weak PAH emission features. The Mrk 279 spectral energy distribution shows a mid-IR bump, which extends from 2 to 15-20 micron . The mid-IR bump is consistent with thermal emission from dust grains at a distance of >= 100 light-days. No significant variations of the mid-IR flux have been detected during our observing campaign, consistent with the relatively low amplitude (~10 % rms) of the optical variability during the campaign. The time delay for the Hbeta line emission in response to the optical continuum variations is 16.7 +5.3/5.6 days, consistent with previous measurements., In press in Astronomy and Astrophysics (main journal) 12 pages, 5 figures