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Resumen del póster presentado al XIII Scientific Meeting of the Spanish Astronomical Society, celebrado en la Universidad de Salamanca del 16 al 20 de julio de 2018., According to the Unified Model of Active Galactic Nuclei (AGN), unobscured AGN based on its optical spectrum (detection of rest-frame UV-optical broad emission lines, type-1 AGN) should appear as X-ray unabsorbed AGN. However, there is an important fraction (10-30%) of AGN whose optical and X-ray classifications do not match, and the origin of the discrepancy is not clear. To provide insight into this topic, we have conducted a statistical analysis of the optical obscuration and X-ray absorption properties of the optically type1 AGN from the Bright Ultra-hard XMM-Newton Survey (BUXS) with L2−10keV >1042 erg s−1 and z=0.05-1. We have high-quality spectra from XMM-Newton and either SDSS spectra or proprietary observations for the selected sample. In order to provide the most complete sample as possible, we have conducted a detailed analysis of the emission lines to provide a reliable classification of the AGNs. We derive the X-ray absorption by fitting their XMM-Newton spectra and the optical extinction using UV/optical spectral continuum fits. As BUXS is a flux limited X-ray selected sample at hard energies (f4.510keV ≤6×10−14 ergs−1cm−2), it is complete for NH column densities up to the Compton-thick limit (∼1024cm−2). Our preliminary results show that most type-1 AGN in our sample show consistent optical and X-ray classification, but there is a large fraction ( 20%) of objects with large NH column densities (NH >4×1021 cm−2).

[Context] XMM-Newton has observed the X-ray sky since early 2000. The XMM-Newton Survey Science Centre Consortium has published catalogues of X-ray and ultraviolet sources found serendipitously in the individual observations. This series is now augmented by a catalogue dedicated to X-ray sources detected in spatially overlapping XMM-Newton observations. [Aims] The aim of this catalogue is to explore repeatedly observed sky regions. It thus makes use of the long(er) effective exposure time per sky area and offers the opportunity to investigate long-term flux variability directly through the source-detection process. [Methods] A new standardised strategy for simultaneous source detection on multiple observations was introduced, including an adaptive-smoothing method to describe the image background. It was coded as a new task within the XMM-Newton Science Analysis System and used to compile a catalogue of sources from 434 stacks comprising 1789 overlapping XMM-Newton observations that entered the 3XMM-DR7 catalogue, have a low background and full-frame readout of all EPIC cameras. [Results] The first stacked catalogue is called 3XMM-DR7s. It contains 71 951 unique sources with positions and parameters such as fluxes, hardness ratios, quality estimates, and information on inter-observation variability, directly derived from a simultaneous fit. Source parameters are calculated for the stack and for each contributing observation. About 15% of the sources are new with respect to 3XMM-DR7. Through stacked source detection, the parameters of repeatedly observed sources are determined with higher accuracy than in the individual observations. The method is more sensitive to faint sources and tends to produce fewer spurious detections. [Conclusions] With this first stacked catalogue we demonstrate the feasibility and benefit of the approach. It supplements the large data base of XMM-Newton detections with additional, in particular faint, sources and adds variability information. In the future, the catalogue will be expanded to larger samples and continued within the series of serendipitous XMM-Newton source catalogues., NW, MC, and FK acknowledge the CNES support. FJC acknowledges financial support through grant AYA2015-64346-C2-1P (MINECO/FEDER) and MTC through grant ESP2016-76683-C3-1R (MINECO/FEDER), both funded by the Agencia Estatal de Investigación, Unidad de Excelencia María de Maeztu.

Astro2020 Science White Paper: et al., The discoveries made over the past 20 years by Chandra and XMM-Newton surveys in conjunction with multiwavelength imaging and spectroscopic data available in the same fields have significantly changed the view of the supermassive black hole (SMBH) and galaxy connection. These discoveries have opened up several exciting questions that are beyond the capabilities of current X-ray telescopes and will need to be addressed by observatories in the next two decades. As new observatories peer into the early Universe, we will begin to understand the physics and demographics of SMBH infancy (at z > 6) and investigate the influence of their accretion on the formation of the first galaxies (§ 2.1). We will also be able to understand the accretion and evolution over the cosmic history (at z ∼1–6) of the full population of black holes in galaxies, including low accretion rate, heavily obscured AGNs at luminosities beyond the reach of current X-ray surveys (§2.2 and §2.3), enabling us to resolve the connection between SMBH growth and their environment.

[Aims]: We aim to study the variability properties of bright hard X-ray selected active galactic nuclei (AGN) in the redshift range between 0.3 and 1.6 detected in the Chandra Deep Field South (XMM-CDFS) by a long (∼3 Ms) XMM observation. [Methods]: Taking advantage of the good count statistics in the XMM CDFS, we search for flux and spectral variability using the hardness ratio (HR) techniques. We also investigate the spectral variability of different spectral components (photon index of the power law, column density of the local absorber, and reflection intensity). The spectra were merged in six epochs (defined as adjacent observations) and in high and low flux states to understand whether the flux transitions are accompanied by spectral changes. [Results]: The flux variability is significant in all the sources investigated. The HRs in general are not as variable as the fluxes, in line with previous results on deep fields. Only one source displays a variable HR, anti-correlated with the flux (source 337). The spectral analysis in the available epochs confirms the steeper when brighter trend consistent with Comptonisation models only in this source at 99% confidence level. Finding this trend in one out of seven unabsorbed sources is consistent, within the statistical limits, with the 15% of unabsorbed AGN in previous deep surveys. No significant variability in the column densities, nor in the Compton reflection component, has been detected across the epochs considered. The high and low states display in general different normalisations but consistent spectral properties. [Conclusions]: X-ray flux fluctuations are ubiquitous in AGN, though in some cases the data quality does not allow for their detection. In general, the significant flux variations are not associated with spectral variability: Photon index and column densities are not significantly variable in nine out of the ten AGN over long timescales (from three to six and a half years). Photon index variability is found only in one source (which is steeper when brighter) out of seven unabsorbed AGN. The percentage of spectrally variable objects is consistent, within the limited statistics of sources studied here, with previous deep samples., S.F. acknowledges the Swedish National Space Board and the Knut & Alice Wallenberg Foundation. F.J.C. acknowledges financial support through grant AYA2015-64346-C2-1P (MINECO/FEDER).

Resumen del trabajo presentado al XXIX XMM-Newton SSC consortium meeting, celebrado en Madrid (España) del 14 al 15 de marzo de 2016., To provide insight into the apparent mismatch between the optical and X-ray absorption properties observed in 10-30 % of Active Galactic Nuclei (AGN), we have conducted a detailed study of two X-ray unabsorbed AGN with a type-2 optical spectroscopic classification. In addition to high quality X-ray spectroscopic observations, that we used to determine both the AGN luminosities and absorption, we have a VLT/XSHOOTER UV-to-near-IR high resolution spectrum for each object, that we used to determine the AGN intrinsic emision corrected for both contamination from the AGN hosts and extinction. Thanks to the high quality data available for these two intriguing sources, we unveil the origin of the mismatch. The most likely explanation is that both objects have an intrinsically high dust-to-gas ratio. In addition, we are conducting an statistical analysis of the optical obscuration and X-ray absorption properties of 159 Type-1 AGN drawn from BUXS to determine the distribution of dust-to-gas ratios in AGN over a broad range of luminosities and redshifts.

Resumen del trabajo presentado al Symposium X-Ray Universe, celebrado en Dublín (Irlanda) del 16 al 19 de junio de 2014., We have investigated whether the dusty tori invoked in the standard orientation-based unified scheme of Active Galactic Nuclei (AGN) is valid for all AGN types at both low and high luminosities. We used the Bright Ultra-hard XMM-Newton Survey (BUXS), one of the largest flux-limited samples of bright AGN selected above 4.5 keV with XMM-Newton, and the Wide-field Infrared Survey Explorer (WISE). BUXS includes 255 AGN detected over 44 deg2 of which to date 161 are identified as type 1 AGN and 89 as type 2 AGN and 98% are detected with WISE. We determined the distribution of covering factors of the obscuring region in X-ray type 1 and type 2 AGN by computing the AGN power re-processed into the IR (apparent covering factors) and the torus geometrical covering factor (i.e. the relative fraction of obscured AGN) using the clumpy torus models of Nenkova et al. We have also investigated whether our results favor the so-called receding torus scenario. Finally, I will discuss the possibility of using the spectral energy distributions of the sources in the 3XMM-DR4 catalogue, produced by the >Astronomical Resource Cross-matching for High Energy Studies> (ARCHES) project, to extend such studies over a broader range of AGN parameters.

Trabajo presentado al Symposium the X-ray Universe, celebrado en Dublin (Irlanda) del 16 al 19 de junio de 2014., The X-ray spectra of Active Galactic Nuclei (AGN) unveil properties of matter accreting onto the Super Massive Black Hole (SMBH). We investigate the X-ray spectra of AGN focusing on Compton reflection and fluorescence. These are two of the most important processes of interaction between the primary radiation and circum-nuclear material located far away from the SMBH, as indicated by the presence of unresolved spectral emission lines (most notably the Fe line at 6.4 keV rest-frame) in the X-ray spectra of AGN. Contributions from the inner accretion disk, as expected affected by relativistic effects, have been also detected in several AGN. We study the average X-ray spectrum of a sample of 263 AGN totalising 419023 counts in the 2-10 keV rest-frame band distributed among 388 spectra with the EPIC cameras on board of XMM-Newton. The sample was selected from the cross-correlation between the 2XMM X-ray source catalogue and the Vèron-Cetty-Vèron QSO and AGN sample. The most relevant fits to the average spectrum were made using primary radiation with components of Compton reflection and fluorescence. We first considered that these two components are emitted for interaction with matter located far away from the SMBH (e.g. the torus). Then we added the contribution from the accretion disk, smeared by relativistic effects. A reflection model by distant material is very significantly detected, but the fit improves at 6 sigma when neutral disk-reflection is added. The reflection factors are 0.65 for the accretion disk and 0.25 for the torus. Replacing the neutral disk-reflection with low-ionisation disk-reflection fits the data equally well and suggests that the accretion disk is mildly ionised. We detect distant neutral reflection associated with a narrow Fe line in the average spectrum of unabsorbed AGN with average redshift 0.8. Adding the disk-reflection component associated with a relativistic Fe line improves the data description at 6 sigma confidence level, suggesting that both reflection components are present.

There exists a significant population of broad line, z∼ 2 quasi-stellar objects (QSOs) which have heavily absorbed X-ray spectra. Follow-up observations in the submillimetre show that these QSOs are embedded in ultraluminous starburst galaxies, unlike most unabsorbed QSOs at the same redshifts and luminosities. Here we present X-ray spectra from XMM–Newton for a sample of five such X-ray-absorbed QSOs that have been detected at submillimetre wavelengths. We also present spectra in the rest-frame ultraviolet from ground-based telescopes. All the five QSOs are found to exhibit strong C iv absorption lines in their ultraviolet spectra with equivalent width >5 Å. The X-ray spectra are inconsistent with the hypothesis that these objects show normal QSO continua absorbed by low-ionization gas. Instead, the spectra can be modelled successfully with ionized absorbers, or with cold absorbers if they possess unusually flat X-ray continuum shapes and unusual optical to X-ray spectral energy distributions. We show that the ionized absorber model provides the simplest, most self-consistent explanation for their observed properties. We estimate that the fraction of radiated power that is converted into kinetic luminosity of the outflowing winds is typically ∼4 per cent, in agreement with recent estimates for the kinetic feedback from QSOs required to produce the M–σ relation, and consistent with the hypothesis that the X-ray-absorbed QSOs represent the transition phase between obscured accretion and the luminous QSO phase in the evolution of massive galaxies., SRON is supported financially by NWO, the Netherlands Organization for Scientific Research. FJC acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación (previously Ministerio de Educación y Ciencia), under projects ESP2006-13608-C02-01, AYA2009-08059 and AYA2010-21490-C02-01.

We present here photometric redshift confirmation of the presence of large-scale structure around the z= 1.82 quasi-stellar object (QSO) RX J0941, which shows an overdensity of submillimetre (submm) sources. Radio imaging confirms the presence of the submm sources and pinpoints their likely optical near-infrared (NIR) counterparts. Four of the five submm sources present in this field (including the QSO) have counterparts with redshifts compatible with z= 1.82. We show that our photometric redshifts are robust against the use of different spectral templates. We have measured the galaxy stellar mass of the submm galaxies from their rest-frame K-band luminosity obtaining log(M*/M⊙) ∼ 11.5 ± 0.2, slightly larger than the Schechter mass of present-day galaxies, and hence indicating that most of the stellar mass is already formed. We present optical-to-radio spectral energy distributions (SEDs) of the five Submillimetre Common-User Bolometer Array (SCUBA) sources. The emission of RX J0941 is dominated by reprocessed active galactic nucleus (AGN) emission in the observed mid-IR (MIR) range, while the starburst contribution completely dominates in the submm range. The SEDs of the other three counterparts are compatible with a dominant starburst contribution above ∼24 μm, with star formation rates ∼2000 M⊙ yr−1, central dust masses log(Mdust/M⊙) ∼ 9 ± 0.5 and hence central gas masses log(Mgas/M⊙) ∼ 10.7. There is very little room for an AGN contribution. From X-ray upper limits and the observed 24 μm flux, we derive a maximum 2–10 keV X-ray luminosity of 1044 erg s−1 for any putative AGN, even if they are heavily obscured. This in turn points to relatively small black holes with log(M•/M⊙) ≲ 8 and hence stellar-to-black hole mass ratios about 1 order of magnitude higher than those observed in the present Universe: most of their central black hole masses are still to be accreted. Local stellar-to-black hole mass ratios can be reached if ∼1.3 per cent of the available nuclear gas mass is accreted., FJC, JE and SF acknowledge financial support from the Spanish Ministerio de Educación y Ciencia (later Ministerio de Ciencia e Innovación) under projects ESP2006-13608-C02-01 and AYA2009-08059. FJC, JAS and MJP acknowledge further support from the Royal Society.

We present the first results of the spectroscopy of distant, obscured AGN as obtained with the ultra-deep (≈3.3 Ms) XMM-Newton survey in the Chandra deep field South. One of the primary goals of the project is to characterize the X-ray spectral properties of obscured and heavily obscured Compton-thick AGN over the range of redhifts and luminosities that are relevant in terms of their contribution to the X-ray background. The ultra-deep exposure, coupled with the XMM detector’s spectral throughput, allowed us to accumulate good quality X-ray spectra for a large number of X-ray sources and, in particular, for heavily obscured AGN at cosmological redshifts. Specifically we present the X-ray spectral properties of two high-redshift – z = 1.53 and z = 3.70 – sources. The XMM spectra of both are very hard, with a strong iron Kα line at a rest-frame energy of ~6.4 keV. A reflection-dominated continuum provides the best description of the X-ray spectrum of the z = 1.53 source, while the intrinsic continuum of the z = 3.70 AGN is obscured by a large column NH ≈ 1024 cm-2 of cold gas. Compton-thick absorption, or close to it, is unambiguously detected in both sources. Interestingly, these sources would not be selected as candidate Compton thick AGN by some multiwavelength selection criteria based on the mid-infrared to optical and X-ray to optical flux ratios., Support from the Italian Space Agency (ASI) under the contracts ASI-INAF I/088/06/0 and I/009/10/0 is acknowledged. A.C. acknowledges the NASA grant NNX09AQ05G to visit CfA, where part of this work was written. I.G. and A.C. acknowledge the Marie Curie fellowship FP7-PEOPLE-IEF-2008 Prop. 235285. X.B. and F.J.C. acknowledge financial support from the Spanish Ministerio de Ciencia e Innovación under project AYA2009-08059. M.B. acknowledges support by the Deutsches Zentrum für Luft- und Raumfahrt, DLR project numbers 50 OR 0207 and 50 OR 0405. F.C., F.N. and M.B. acknowledge NASA grants NNX08AX51G and NNX09AQ05G. F.C. acknowledges support from the Blanceflor Boncompagni Ludovisi Foundation. J.D.S. is supported by World Premier International (WPI) Research Center Initiative , MEXT, Japan. W.N.B. acknowledges NASA grant SV0-80004 and NASA ADP grant NNX10AC99G. F.E.B. cknowledges the support of CONICYT, Chile, under grants FONDECYT 1101024 and FONDAP (CATA) 15010003.

Trabajo presentado a la X-Ray Astronomy: Present status, multi-wavelength approach and future perspectives, celebrada en Bolonia (Italia) del 7 al 11 de septiembre de 2009., There exists a population of broad-line z∼2 QSOs which have heavily absorbed X-ray spectra. These objects constitute ∼10% of the population at luminosities and redshifts characteristic of the main producers of QSO luminosity in the Universe. Our follow up observations in the submm show that these QSOs are often embedded in ultraluminous starburst galaxies, unlike most unabsorbed QSOs at the same redshifts and luminosities. The radically different star formation properties between the absorbed and unabsorbed QSOs implies that the X-ray absorption is unrelated to the torus invoked in AGN unification schemes. Instead, these results suggest that the objects represent a transitional phase in an evolutionary sequence relating massive black holes and the formation of galaxies. The most puzzling question about these objects has always been the nature of the X-ray absorber. We present our study of the X-ray absorbers based on deep (50-100ks) XMM-Newton spectroscopy. We show that the absorption is most likely due to a dense ionised wind driven by the QSO. This wind could be the mechanism by which the QSO terminates the star formation in the host galaxy, and ends the supply of accretion material, to produce the present day black hole/spheroid mass ratio.

[Aims]: Pointed observations with XMM-Newton provide the basis for creating catalogues of X-ray sources detected serendipitously in each field. This paper describes the creation and characteristics of the 2XMM catalogue. [Methods]: The 2XMM catalogue has been compiled from a new processing of the XMM-Newton EPIC camera data. The main features of the processing pipeline are described in detail. [Results]: The catalogue, the largest ever made at X-ray wavelengths, contains 246 897 detections drawn from 3491 public XMM-Newton observations over a 7-year interval, which relate to 191 870 unique sources. The catalogue fields cover a sky area of more than 500 deg2. The non-overlapping sky area is ∼360 deg2 (∼1% of the sky) as many regions of the sky are observed more than once by XMM-Newton. The catalogue probes a large sky area at the flux limit where the bulk of the objects that contribute to the X-ray background lie and provides a major resource for generating large, well-defined X-ray selected source samples, studying the X-ray source population and identifying rare object types. The main characteristics of the catalogue are presented, including its photometric and astrometric properties., M. Ceballos, F. Carrera and X. Barcons acknowledge financial support by the Spanish Ministerio de Educacion y Ciencia under projects ESP2003-00812 and ESP2006-13608-C02-01. The French teams are grateful to CNES for supporting this activity. In Germany the XMM-Newton project is supported by the Bundesministerium für Wirtschaft und Technologie/Deutsches Zentrum für Luft und Raumfahrt e.V. (DLR) and the Max Planck Society. Part of this work was supported by the DLR project numbers 50 OX 0201, 50 OX 0001, and 50 OG 0502. The Italian team acknowledges financial support from the Agenzia Spaziale Italiana (ASI), the Ministero dell’ Istruzione, Università e Ricerca (MIUR) and the Istituto Nazionale di Astrofisica (INAF) over the last years; they are currently supported by the grant PRIN-MIUR 2006-02-5203 and by the ASI grants n.I/088/06/0 and n.I/023/05/0. UK authors thank STFC for financial support.

Trabajo presentado a la X-Ray Astronomy: Present status, multi-wavelength approach and future perspectives, celebrada en Bolonia (Italia) del 7 al 11 de septiembre de 2009., We present the angular correlation function of the X-ray population of 1063 XMM-Newton observations at high Galactic latitudes, comprising up to ~30000 sources over a sky area of ~125 sq. degrees in the energy bands: soft (0.5-2 keV) and hard (2-10 keV). This is the largest sample of serendipitous X-ray sources ever used for clustering analysis purposes to date and the results have been determined with unprecedented accuracy. We detect significant clustering signals in the soft and hard bands (~10 sigma and ~5 sigma, respectively). We deproject the angular correlation function via Limber's equation and calculate the typical spatial lengths. We infer that AGN at redshifts ~1 are embedded in dark matter halos with typical masses of log M ~ 12.6/h Msol and lifetimes in the range ~3-5 x 10^8 years, which indicates that AGN activity is a transient phase in the life of galaxies.

[Context]: One of the most important parameters in the XRB (X-ray background) synthesis models is the average efficiency of accretion onto SMBH (super-massive black holes). This can be inferred from the shape of broad relativistic Fe lines seen in X-ray spectra of AGN (active galactic nuclei). Several studies have tried to measure the mean Fe emission properties of AGN at different depths with very different results. [Aims]: We compute the mean Fe emission from a large and representative sample of AGN X-ray spectra up to redshift ∼3.5. [Methods]: We developed a method of computing the rest-frame X-ray average spectrum and applied it to a large sample (more than 600 objects) of type 1 AGN from two complementary medium sensitivity surveys based on XMM-Newton data, the AXIS and XWAS samples. This method makes use of medium-to-low quality spectra without needing to fit complex models to the individual spectra but with computing a mean spectrum for the whole sample. Extensive quality tests were performed by comparing real to simulated data, and a significance for the detection of any feature over an underlying continuum was derived. [Results]: We detect with a 99.9% significance an unresolved Fe Kα emission line around 6.4 keV with an EW ∼ 90 eV, but we find no compelling evidence of any significant broad relativistic emission line in the final average spectrum. Deviations from a power law around the narrow line are best represented by a reflection component arising from cold or low-ionization material. We estimate an upper limit for the EW of any relativistic line of 400 eV at a 3σ confidence level. We also marginally detect the so-called Iwasawa-Taniguchi effect on the EW for the unresolved emission line, which appears weaker for higher luminosity AGN. [Conclusions]: We computed an upper limit for the average relativistic Fe Kα line contribution that is significantly lower than previously reported values from similar analyses. Our results, however, are in excellent agreement with individual analyses of local AGN samples. We attribute this difference either to our more sophisticated method of modeling the underlying continuum, to intrinsic differences in source populations, and/or to the uneven data quality of the individual spectra of the various samples., Partial financial support for this work was provided by the Spanish Ministerio de Educación y Ciencia under project ESP2006−13608. A.C. acknowledges financial support from a Spanish Ministerio de Educación y Ciencia fellowship and also from the MIUR and The Italian Space Agency (ASI) grants PRIN−MUR 2006−02−5203 and n. I/088/06/0. M.J.P., S.M., J.A.T. and M.G.W. acknowledge support from the UK STFC research council. M.C. is supported by the Deutsches Zentrumfuer Luft-und Raumfahrl (DLR) GmbH under contract No. FKZ50 OR 0404.

[Aims]: We present the optical classification and redshift of 348 X-ray selected sources from the XMM-Newton Bright Serendipitous Survey (XBS), which contains a total of 400 objects (identification level=87%). About 240 are new identifications. In particular, we discuss in detail the classification criteria adopted for the active galactic nuclei (AGNs) population. [Methods]: By means of systematic spectroscopic campaigns using various telescopes and through the literature search, we have collected an optical spectrum for the large majority of the sources in the XBS survey and applied a well-defined classification >flow chart>. [Results]: We find that the AGNs represent the most numerous population at the flux limit of the XBS survey (~10-13 erg cm-2s-1) constituting 80% of the XBS sources selected in the 0.5-4.5 keV energy band and 95% of the >hard> (4.5-7.5 keV) selected objects. Galactic sources populate the 0.5-4.5 keV sample significantly (17%) and only marginally (3%) the 4.5-7.5 keV sample. The remaining sources in both samples are clusters/groups of galaxies and normal galaxies (i.e. probably not powered by an AGN). Furthermore, the percentage of type 2 AGNs (i.e. optically absorbed AGNs with 2$]]> mag) dramatically increases going from the 0.5-4.5 keV sample (%) to the 4.5-7.5 keV sample (%). We finally propose two simple diagnostic plots that can be easily used to obtain the spectral classification for relatively low-redshift AGNs even if the quality of the spectrum is not good., A.C., R.D.C., T.M., and P.S. acknowledge financial support from the MIUR, grant PRIN-MUR 2006-02-5203 and from the Italian Space Agency (ASI), grants n. I/088/06/0 and n. I/023/05/0.

We present the first NuSTAR observation of a 'true' type 2 Seyfert galaxy. The 3-40 keV X-ray spectrum of NGC 3147 is characterized by a simple power-law, with a standard γ ~ 1.7 and an iron emission line, with no need for any further component up to ~40 keV. These spectral properties, together with significant variability on time-scales as short as weeks (as shown in a 2014 Swift monitoring campaign), strongly support an unobscured line of sight for this source. An alternative scenario in terms of a Compton-thick source is strongly disfavoured, requiring an exceptional geometrical configuration, whereas a large fraction of the solid angle to the source is filled by a highly ionized gas, whose reprocessed emission would dominate the observed luminosity. Moreover, in this scenario, the implied intrinsic X-ray luminosity of the source would be much larger than the value predicted by other luminosity proxies, like the [OIII ]λ5007 emission-line extinction-corrected luminosity. Therefore, we confirm with high confidence that NGC 3147 is a true type 2 Seyfert galaxy, intrinsically characterized by the absence of a broad-line region., SB acknowledges financial support from the Italian Space Agency under grant ASI-INAF I/037/12/0. AM and GM acknowledge financial support from the Italian Space Agency under grant ASI/INAF I/037/12/0-011/13. AM acknowledges financial support from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 312789. FP acknowledges the ASI/INAF agreement number 2013-023-R1. XB and FJC acknowledge financial support through grant AYA2015-64346-C2-1-P (MINECO/FEDER)