A broadband X-ray view of the NLSy1 1E 0754.6+3928

Abstract

Context. The soft X-ray band of many active galactic nuclei (AGN) is affected by obscuration due to partially ionised matter crossing our line of sight. In this context, two past XMM-Newton observations (6 months apart) and a simultaneous NuSTAR-Swift (∼8 years later) exposure of the Narrow Line Seyfert 1 galaxy 1E 0754.6+392.8 revealed an intense and variable WA and hints of additional absorbers in the Fe Kα band. Aims. We aim at providing the first X-ray characterisation of this AGN discussing its broadband (0.3-79 keV) spectrum and temporal properties. Methods. We conduct a temporal and spectroscopic analysis on two ∼10 ks (net exposure) XMM-Newton snapshots performed in April and October 2006. We also study the high energy behaviour of 1E 0754.6+392.8 modelling its broadband spectrum using simultaneous Swift-NuSTAR data. Both phenomenological and physically motivated models are tested. Results. We find the presence of flux variability (∼150% and 30% for 0.3-2 and 2-10 keV bands, respectively) and spectral changes at months timescales (∆Γ ∼0.4). A reflection component that is consistent with being constant over years and arising from relatively cold material far from the central super massive black hole is detected. The main spectral feature shaping the 1E 0754.6+392.8 spectrum is a warm absorber. Such a component is persistent over the years and variability of its ionisation and column density is observed down on months in the ranges 3×10 22 cm −2 N H 7.2 × 10 22 cm −2 and 1.5 log(ξ/erg s −1 cm) 2.1. Despite the short exposures, we find possible evidence of two additional high-ionisation and high-velocity outflow components in absorption. Conclusions. Our analysis suggests the existence of a complex system of absorbers in 1E 0754.6+392.8. Longer exposures are mandatory in order to characterise, on more solid grounds, the absorbers in this AGN.

The properties of the X-ray corona in the distant ($z=3.91$) quasar APM 08279+5255

“…L19 included also the median values, binned in compactness (i.e., L X ), of the large BASS sample of local AGN as measured by Ricci et al (2018). 2 0 0 0 -1 0 -1 1 2 0 0 2 -0 2 -2 4 2 0 0 7 -1 0 -0 6 2 0 0 8 -0 1 -1 4 2 0 1 9 -0 3 -2 4 the L X -E cut plane of L19 further updated with our measurement, the pair-production critical lines for M BH = 10 10 M , and results from other recent works, derived through canonical modeling of the continuum (Kara et al 2017;Tortosa et al 2018;Kamraj et al 2018;Ursini et al 2020;Baloković et al 2020;Middei et al 2020Middei et al , 2021Reeves et al 2021, see also Ezhikode et al 2020, where the authors model X-ray reflection accounting for relativistic effects). When multiple estimates for a same source are available, we only kept the latest one.…”

The properties of the X-ray corona in the distant (z= 3.91) quasar APM 08279+5255

“…L19 included also the median values, binned in compactness (i.e., L X ), of the large BASS sample of local AGN as measured by Ricci et al (2018). Figure 4 (left) shows the L X −E cut plane of L19 further updated with our measurement, the pair-production critical lines for M BH = 10 10 M , and results from other recent works, derived through canonical modeling of the continuum (Kara et al 2017;Tortosa et al 2018;Kamraj et al 2018;Ursini et al 2020;Baloković et al 2020;Middei et al 2020Middei et al , 2021Reeves et al 2021; see also Ezhikode et al 2020, where the authors model X-ray reflection accounting for relativistic effects). When multiple estimates for a same source are available, we only kept the latest one.…”

X-ray obscuration from a variable ionized absorber in PG 1114+445

“…In the last decade many obscuring variable absorbers were found in the X-ray spectra of nearby AGN (e.g., Markowitz et al 2014), with timescales ranging from decades (e.g., Kaastra et al 2014) to months or weeks (e.g., Matzeu et al 2016;Mehdipour et al 2017;Middei et al 2020) and even days (e.g, Braito et al 2014;Severgnini et al 2015). These winds, with velocities than can be higher than typical WA velocities, are important because they may carry sufficient kinetic power to contribute to possible AGN feedback on the host galaxy.…”

“…The absorbers are sometimes found to be persistent for about a decade (e.g., NGC 5548, Kaastra et al 2014). In other cases, the obscurer has a much shorter variability timescale (e.g., Severgnini et al 2015;Matzeu et al 2016;Mehdipour et al 2017;Middei et al 2020). In a few other cases, a source was found in an higher flux state than its usual one, due to a diminished obscuring power of the WA (e.g., Braito et al 2014).…”