Related papers: Flares in the Changing Look AGN Mrk 590. II: Deep …

Mrk 590 is a known changing-look AGN which almost turned off in 2012, and then in 2017 partially re-ignited into a repeat flaring state, unusual for an AGN. Our \emph{Swift} observations since 2013 allow us to characterise the…

We have studied the nature and origin of the soft X-ray excess detected in the interesting changing-look AGN (CLAGN) Mrk~590 using two decades of multi-wavelength observations from \xmm{}, \suzaku{}, \swift{} and \nustar{}. In the light of…

Active Galactic Nuclei (AGN) are the most luminous persistent objects in the universe. An excess of X-ray emission below about 2 keV, called soft-excess, is very common in Type 1 AGN spectra. The origin of this feature remains debated.…

Changing-Look AGN (CLAGN) Mkn 590 recently underwent a sudden re-ignition, marked by substantial increases in optical/UV and X-ray continuum flux since last couple of years. Swift-XRT observations revealed the re-emergence of a soft X-ray…

Probing the physics of the accretion flow around active galactic nuclei (AGN) is crucial to understanding their emission mechanisms as well as being able to constrain the geometrical and variability properties of the different regions…

We present a thorough study of the Changing-Look Active Galactic Nucleus (CL-AGN) Mrk 1018, utilizing an extensive dataset spanning optical, UV, and X-ray spectro-photometric data from 2005 to 2019. We analysed X-ray spectra and broad-band…

Significant variability in broad emission line strengths of active galactic nuclei (AGN) over months to years has been observed, often accompanied by intrinsic continuum changes. Such spectral variability challenges the traditional AGN…

Optical changing-look Active Galactic Nuclei (AGN) are a class of sources that change type within a short timescale of years or decades. This change is characterised by the appearance or disappearance of broad emission lines, often…

"Changing look" Active Galactic Nuclei (AGN) are a subset of Seyfert galaxies characterized by rapid transitions between Compton-thin and Compton-thick regimes. In their Compton-thin state, the central engine is less obscured, hence…

[Abridged] The X-ray broadband spectra of the bare AGN Mrk 110, obtained by simultaneous XMM-Newton and NuSTAR observations (Nov 2019 and April 2020), are characterised by the presence of a prominent and absorption-free smooth soft X-ray…

Changing-look AGNs (CLAGN) are accreting supermassive black hole systems that undergo variations in optical spectral type, driven by major changes in accretion rate. Mrk 1018 has undergone two transitions, a brightening event in the 1980s…

The Changing-Look active galactic nucleus Mkn 590 is currently in a rejuvenated state, exhibiting a contemporaneous flux rise across X-rays, UV, optical and cm wavelengths. In this study, we present three new optical spectra obtained with…

The X-ray spectra of many active galactic nuclei (AGN) show a soft X-ray excess below 1-2 keV on top of the extrapolated high- energy power law. The origin of this component is uncertain. It could be a signature of relativistically blurred,…

Aims. We present a 0.2--200 keV broad-band study of absorbed AGN observed with INTEGRAL, XMM-Newton, Chandra and ASCA to investigate the continuum shape and the absorbing/reflecting medium properties. Methods. The sources are selected in…

We report the discovery of large amplitude X-ray variability in the low luminosity AGN (LLAGN) MGC 7589, and present possible observational evidence for accretion mode transition in this source. Long-term X-ray flux variations by a factor…

We perform an X-ray spectral analysis of the brightest and cleanest bare AGN known so far, Ark 120, in order to determine the process(es) at work in the vicinity of the SMBH. We present spectral analysis of data from an extensive campaign…

Strong soft X-ray emission called soft X-ray excess is often observed in luminous active galactic nuclei (AGN). It has been suggested that the soft X-rays are emitted from a warm ($T=10^6\sim10^7\ \rm{K}$) region that is optically thick for…

We model the broadband (optical/UV and X-ray) continuum spectrum of the "changing-look" active galactic nucleus (AGN) Mrk 1018 as it fades from Seyfert 1 to 1.9 in $\sim 8$ years. The brightest spectrum, with Eddington ratio $L/L_{\rm…

Changing-state active galactic nuclei (CSAGNs) exhibit rapid variability, with mass accretion rates that can change by several orders of magnitude in a few years. This provides us with a unique opportunity to study the evolution of the…

Mrk 590 was originally classified as a Seyfert 1 galaxy, but then it underwent dramatic changes: the nuclear luminosity dropped by over two orders of magnitude and the broad emission lines all but disappeared from the optical spectrum. Here…