The soft excess of the NLS1 galaxy Mrk 359 studied with an XMM-Newton-NuSTAR monitoring campaign

Abstract

XMM-Newton and NuSTAR multiple exposures allow us to disentangle the different emission components of active galactic nuclei (AGNs) and to study the evolution of their different spectral features. In this work, we present the timing and spectral properties of five simultaneous XMM-Newton and NuSTAR observations of the Narrow Line Seyfert 1 galaxy Mrk 359. We aim to provide the first broadband spectral modeling of Mrk 359 describing its emission spectrum from the UV up to the hard X-rays. To do this, we performed temporal and spectral data analysis, characterising the amplitude and spectral changes of the Mrk 359 time series and computing the 2-10 keV normalised excess variance. The spectral broadband modelling assumes the standard hot Comptonising corona and reflection component, while for the soft excess we tested two different models: a warm, optically thick Comptonising corona (the two-corona model) and a reflection model in which the soft-excess is the result of a blurred reflected continuum and line emission (the reflection model). High and low flux states were observed during the campaign. The former state has a softer spectral shape, while the latter shows a harder one. The photon index is in the 1.75-1.89 range, and only a lower limit to the hot-corona electron temperature can be found. A constant reflection component, likely associated with distant matter, is observed. Regarding the soft excess, we found that among the reflection models we tested, the one providing the better fit (reduced ${\chi }^2$=1.14) is the high-density one. However, a significantly better fit (reduced ${\chi }^2$=1.08) is found by modelling the soft excess with a warm Comptonisation model. The present analysis suggests the two-corona model as the best scenario for the optical-UV to X-ray emission spectrum of Mrk 359.

12 pages, 14 figures. Accepted for publication in A&A

References in corpus (18)

• HI4PI: A full-sky HI survey based on EBHIS and GASS
• X-ray reverberation around accreting black holes
• The role of the reflection fraction in constraining black hole spin
• Universal bolometric corrections for AGN over 7 luminosity decades
• CAIXA: a Catalogue of AGN In the XMM-Newton Archive I. Spectral analysis
• XMM-Newton study of the complex and variable spectrum of NGC 4051
• The variability plane of accreting compact objects
• Radiation spectra of warm and optically thick coronae in AGN
• A deep X-ray view of the bare AGN Ark120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes
• Tracing the accretion history of supermassive Black Holes through X-ray variability: results from the Chandra Deep Field-South
• Ensemble X-ray variability of Active Galactic Nuclei. II. Excess Variance and updated Structure Function
• The soft X-ray excess: NLS1s vs. BLS1s
• Searching for Ultra-fast Outflows in AGN using Variability Spectra
• NuSTAR/XMM-Newton monitoring of the Seyfert 1 galaxy HE 1143-1810. Testing the two-corona scenario
• The first broadband X-ray view of the narrow line Seyfert 1 Ton S180
• Incoherent fast variability of X-ray obscurers. The case of NGC 3783
• Modelling X-ray RMS spectra I: intrinsically variable AGN
• X-ray flaring in PDS 456 observed in a high-flux state

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• NuSTAR spectral analysis of three Seyfert galaxies: NGC 3227, NGC 5548 and MR 2251$-$178
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