A strong outburst in the X-ray continuum and a change of its Seyfert spectral type was detected in HE 1136-2304 in 2014. The spectral type changed from nearly Seyfert 2 type (1.95) to Seyfert 1.5 type in comparison to previous observations taken ten to twenty years before. In a subsequent variability campaign we wanted to investigate whether this outburst was a single event or whether the variability pattern following the outburst was similar to those seen in other variable Seyfert galaxies
The bright, soft X-ray spectrum Seyfert 1 galaxies Ark 564 and Ton S180 were monitored for 35 days a...
CSS J102913+404220 is an atypical narrow-line Seyfert 1 galaxy with an energetic optical outburst oc...
We present X-ray and optical observations of the X-ray bright AGN 1ES 1927+654. The X-ray observatio...
Aims. A strong outburst in the X-ray continuum and a change of its Seyfert spectral type was detecte...
A strong X-ray outburst was detected in HE 1136-2304 in 2014. Accompanying optical spectra revealed ...
Aims. A strong X-ray outburst was detected in HE 1136-2304 in 2014. Accompanying optical spectra rev...
We report the detection of high-amplitude X-ray flaring of the AGN HE 1136-2304, which is accompanie...
Context. Seyfert 1.8/1.9 are sources showing weak broad H components in their optical spectra. Accor...
We use a model-independent technique to investigate the nature of the 2–15 keV X-ray spectral variab...
We present an analysis of the IUE observations of the Narrow-line Seyfert 1 galaxy IRAS13224-3809. T...
Aims. We analyse data from a 58 month long, continuous Swift/Burst Alert Telescope (BAT) series of o...
Recent X-ray observations have greatly advanced the study of ultrasoft narrow-line Seyfert 1 galaxie...
International audienceChanging-look active galactic nuclei (CL-AGN) have been observed to change opt...
We present X-ray and optical observations of the X-ray bright AGN IES 1927+654. The X-ray observatio...
We report the discovery of a highly X-ray variable AGN, RX J2217.9-5941. This object was bright dur...
The bright, soft X-ray spectrum Seyfert 1 galaxies Ark 564 and Ton S180 were monitored for 35 days a...
CSS J102913+404220 is an atypical narrow-line Seyfert 1 galaxy with an energetic optical outburst oc...
We present X-ray and optical observations of the X-ray bright AGN 1ES 1927+654. The X-ray observatio...
Aims. A strong outburst in the X-ray continuum and a change of its Seyfert spectral type was detecte...
A strong X-ray outburst was detected in HE 1136-2304 in 2014. Accompanying optical spectra revealed ...
Aims. A strong X-ray outburst was detected in HE 1136-2304 in 2014. Accompanying optical spectra rev...
We report the detection of high-amplitude X-ray flaring of the AGN HE 1136-2304, which is accompanie...
Context. Seyfert 1.8/1.9 are sources showing weak broad H components in their optical spectra. Accor...
We use a model-independent technique to investigate the nature of the 2–15 keV X-ray spectral variab...
We present an analysis of the IUE observations of the Narrow-line Seyfert 1 galaxy IRAS13224-3809. T...
Aims. We analyse data from a 58 month long, continuous Swift/Burst Alert Telescope (BAT) series of o...
Recent X-ray observations have greatly advanced the study of ultrasoft narrow-line Seyfert 1 galaxie...
International audienceChanging-look active galactic nuclei (CL-AGN) have been observed to change opt...
We present X-ray and optical observations of the X-ray bright AGN IES 1927+654. The X-ray observatio...
We report the discovery of a highly X-ray variable AGN, RX J2217.9-5941. This object was bright dur...
The bright, soft X-ray spectrum Seyfert 1 galaxies Ark 564 and Ton S180 were monitored for 35 days a...
CSS J102913+404220 is an atypical narrow-line Seyfert 1 galaxy with an energetic optical outburst oc...
We present X-ray and optical observations of the X-ray bright AGN 1ES 1927+654. The X-ray observatio...