Suchergebnisse

We systematically measure the gas-phase metallicities and the mass–metallicity relation of a large sample of local active galaxies for the first time. Observed emission-line fluxes from the Sloan Digital Sky Survey are compared to a four-dimensional grid of photoionization models using the Bayesian parameter estimation code NebulaBayes. For the first time we take into account arbitrary mixing between H ii region and narrow-line region (NLR) emission, and the models are also varied with metallicity, ionization parameter in the NLR, and gas pressure. The active galactic nucleus oxygen abundance is found to increase by ${\rm{\Delta }}{\rm{O}}/{\rm{H}}\sim 0.1$ dex as a function of host galaxy stellar mass over the range $10.1\lt \mathrm{log}{M}_{* }/{M}_{\odot }\lt 11.3$. We also measure the metallicity and ionization parameter of 231,000 star-forming galaxies for comparison with the sample of 7670 Seyfert 2 galaxies. A systematic offset in oxygen abundance of 0.09 dex is observed between the mass–metallicity relations of the star-forming and active galaxies. We investigate potential causes of the offset, including sample selection and the treatment in the models of diffuse ionized gas, pressure, and ionization parameter. We cannot identify the major cause(s), but suspect contributions due to deficiencies in modeling the ionizing spectra and the treatment of dust physics. Optical diagnostic diagrams are presented with the star-forming and Seyfert data colored by the inferred oxygen abundance, ionization parameter, and gas pressure, clearly illustrating the trends in these quantities. ; This research was conducted by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. B.G. acknowledges the support of the Australian Research Council as the recipient of a Future Fellowship (FT140101202). M.D. and R.S. acknowledge support from ARC discovery project #DP160103631. This research is supported by an Australian Government Research Training Program (RTP) Scholarship.

We investigate radiation hardness within a representative sample of 67 nearby (0.02 ≤ z ≤ 0.06) star-forming (SF) galaxies using the integral field spectroscopic data from the MaNGA survey. The softness parameter η = O+/O2+S+/S2+ is sensitive to the spectral energy distribution of the ionizing radiation. We study η via the observable quantity η' (=[O II]/[O III] [S II][S III] ). We analyze the relation between radiation hardness (traced by η and η') and diagnostics sensitive to gas-phase metallicity, electron temperature, density, ionization parameter, effective temperature, and age of ionizing populations. It is evident that low metallicity is accompanied by low log η', i.e. hard radiation field. No direct relation is found between radiation hardness and other nebular parameters though such relations cannot be ruled out. We provide empirical relations between log η and strong emission line ratios N2, O3N2, and Ar3O3, which will allow future studies of radiation hardness in SF galaxies where weak auroral lines are undetected. We compare the variation of [OIII]/[O II] and [S III]/[S II] for MaNGA data with SF galaxies and HII regions within spiral galaxies from literature and find that the similarity and differences between different data set are mainly due to the metallicity. We find that predictions from photoionization models considering young and evolved stellar populations as ionizing sources in good agreement with the MaNGA data. This comparison also suggests that hard radiation fields from hot and old low-mass stars within or around SF regions might significantly contribute to the observed η values. © 2021 The Author(s). ; NK acknowledges financial support from the Schlumberger Foundation, which facilitated her stay at the KICC during which a majority of work was carried out. RA acknowledges support from FONDECYT (Fondo Nacional de Desarrollo Científico y Tecnológico) regular grant 1202007. RM acknowledges ERC (European Research Council) advanced grant 695671 'QUENCH' and support by the Science and Technology Facilities Council (STFC). This project makes use of the MaNGA-Pipe3D data products. We thank the IA-UNAM MaNGA team for creating this catalogue, and the ConaCyt-180125 project for supporting them (Sánchez et al. 2016b). This research made use of Marvin, a core PYTHON package and web framework for MaNGA data, developed by Brian Cherinka, José Sánchez-Gallego, Brett Andrews, and Joel Brownstein (Cherinka et al. 2019); SAOImage DS9, developed by Smithsonian Astrophysical Observatory; and Astropy, a community-developed core PYTHON package for astronomy (Astropy Collaboration 2013). ; With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709. ; Peer reviewed

We present a pilot study aimed to identify large-scale galaxy properties that could play a role in activating a quiescent nucleus. To do so, we compare the properties of two isolated nearby active galaxies and their non-active twins selected from the Calar Alto Legacy Integral Field Area (CALIFA) survey. This pilot sample includes two barred and two unbarred galaxies. We characterize the stellar and ionized gas kinematics and also their stellar content. We obtain simple kinematic models by fitting the full stellar and ionized gas velocity fields and just the approaching or receding sides. We find that the analysed active galaxies present lopsided discs and higher values of the global stellar angular momentum (λR) than their non-active twins. This could be indicating that the stellar discs of the AGN gained angular momentum from the inflowing gas that triggered the nuclear activity. The inflow of gas could have been produced by a twisted disc instability in the case of the unbarred AGN, and by the bar in the case of the barred AGN. In addition, we find that the central regions of the studied active galaxies show older stellar populations than their non-active twins. The next step is to statistically explore these galaxy properties in a larger sample of twin galaxies. © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. ; This study uses data provided by the Calar Alto Legacy Integral Field Area (CALIFA) survey (http://califa.caha.es/).Based on observations collected at the Centro Astronomico Hispano Aleman (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut fur Astronomie and the Instituto de Astrofisica de Andalucia (CSIC). IMC acknowledges the support of the Instituto de Astrofisica de Canarias via an Astrophysicist Resident fellowship. BGL acknowledges support from the Spanish Ministerio de Economia y Competitividad (MINECO) by the grant AYA2015-68217-P. CRA acknowledges the Ramon y Cajal Program of the Spanish Ministry of Economy and Competitiveness through project RYC-2014-15779 and the Spanish Plan Nacional de Astronomia y Astrofisica under grant AYA2016-76682-C3-2-P. TRL acknowledges support via grantsAYA2014-56795-P and AYA2016-77237-C3-1-P from the Spanish Government. JFB acknowledges support from the Spanish Ministerio de Economia y Competitividad (MINECO) by the grant AYA2013-48226-C3-1P. SFS thanks the CONACyT programs CB-285080 and DGAPA IA101217 grants for their support. IMP and JM acknowledges support from the Spanish Ministerio de Economia y Competitividad(MINECO) by the grant AYA2016-76682-C3-1-P. ; Peer reviewed

We present maps for the electron temperature in the inner kpc of three luminous Seyfert galaxies: Mrk 79, Mrk 348, and Mrk 607 obtained from Gemini Multi-Object Spectrograph-integral field unit observations at spatial resolutions of ∼110–280 pc. We study the distributions of electron temperature in active galaxies and find temperatures varying in the range from ∼8000 to ≳30000K. Shocks due to gas outflows play an important role in the observed temperature distributions of Mrk 79 and Mrk 348, while standard photoionization models reproduce the derived temperature values for Mrk 607. In Mrk 79 and Mrk 348, we find direct evidence for shock ionization with overall orientation orthogonal to the ionization axis, where shocks can be easily observed as the active galactic nuclei radiation field is shielded by the nuclear dusty torus. This also indicates that even when the ionization cones are narrow, the shocks can be much wider angle. © 2020 The Author(s). ; This study was financed in part by CNPq, FAPERGS, and FAPESP. AF acknowledges the support from grant PRIN MIUR2017-20173ML3WW−001. EPM acknowledges financial support from the project 'Estallidos6' AYA2016-79724-C4. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the NationalScience Foundation (United States), National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). ; With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709. ; Peer reviewed

et al. ; We investigate the mid-infrared (mid-IR) properties of the largest (42 objects) sample of radio-loud narrow-line Seyfert 1 (RL NLS1) collected to date, using data from the Wide-field Infrared Survey Explorer. We analyse the mid-IR colours of these objects and compare them to what is expected from different combinations of AGN and galaxy templates. We find that, in general, the host galaxy emission gives an important contribution to the observed mid-IR flux in particular at the longest wavelengths (W3, at 12 μm, and W4, at 22 μm). In about half of the sources (22 objects), we observe a very red mid-IR colour (W4 - W3 > 2.5) that can be explained only using a starburst galaxy template (M82). Using the 22 μm luminosities, corrected for the AGN contribution, we have then estimated the star formation rate (SFR) for 20 of these 'red' RL NLS1, finding values ranging from 10 to 500M⊙ yr -1 . For the RLNLS1 showing bluer colours, instead, we cannot exclude the presence of a star-forming (SF) host galaxy although, on average, we expect a lower SFR. Studying the radio (1.4 GHz) to mid-IR (22 μm) flux ratios of the RL NLS1 in the sample, we found that in ~10 objects the SF activity could represent the most important component also at radio frequencies, in addition (or in alternative) to the relativistic jet. We conclude that both the mid-IR and the radio emission of RL NLS1 are a mixture of different components, including the relativistic jet, the dusty torus and an intense SF activity. ; Part of this work was supported by the COST Action MP0905 'Black Holes in a Violent Universe' and by the European Commission Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 267251 Astronomy Fellowships in Italy (AstroFIt). The authors acknowledge financial support from the Italian Ministry of Education, Universities and Research (PRIN2010-2011, grant no. 2010NHBSBE). Support from the Italian Space Agency is acknowledged by LB (contract ASI INAF NuSTAR I/037/12/0). SM acknowledges funding from the Spanish Ministry of Economy and Competitiveness under grant AYA2012-31447, which is partly funded by the FEDER programme. SM acknowledges financial support from the ARCHES project (7th Framework of the European Union, no. 313146). ; Peer Reviewed

10 pags., 9 figs. ; We study the stellar and star formation properties of the host galaxies of 58 X-ray-selected AGNs in the GOODS portion of the Chandra Deep Field South (CDF-S) region at z ∼ 0.5-1.4. The AGNs are selected such that their rest-frame UV to near-infrared spectral energy distributions (SEDs) are dominated by stellar emission; i.e., they show a prominent 1.6 μm bump, thus minimizing the AGN emission >contamination.> This AGN population comprises approximately 50% of the X-ray-selected AGNs at these redshifts. We find that AGNs reside in the most massive galaxies at the redshifts probed here. Their characteristic stellar masses (M*, ∼ 7.8 × 10 10 and M* ∼ 1.2 × 1011 M⊙ at median redshifts of 0.67 and 1.07, respectively) appear to be representative of the X-ray-selected AGN population at these redshifts and are intermediate between those of local type 2 AGNs and high-redshift (z ∼ 2) AGNs. The inferred black hole masses (MBH ∼ 2 × 108 M ⊙) of typical AGNs are similar to those of optically identified quasars at similar redshifts. Since the AGNs in our sample are much less luminous (L2-10 kev downsizing> is due to both a decrease in the characteristic stellar mass of typical host galaxies and less efficient accretion. Finally, there is no strong evidence in AGN host galaxies for either highly suppressed star formation (expected if AGNs played a role in quenching star formation) or elevated star formation when compared to mass-selected (i.e., IRAC-selected) galaxies of similar stellar masses and redshifts. © 2008. The American Astronomical Society. All rights reserved. ; This work was supported by NASA through contract 1255094 issued by the JPL/California Institute of Technology. A. A.-H. acknowledges support from the Spanish Plan Nacional del Espacio under grant ESP2005-01480. P. G. P.-G. acknowledges support from the Ramon y Cajal Fellowship Program financed by the Spanish Government, and from the Spanish Programa Nacional de Astronomıa y Astrofısica under grant AYA 2006-02358. This research has made use of the NASA/ IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration ; Peer Reviewed

Aims. We present a multiwavelength study of an atypical submillimeter galaxy, GH500.30, in the GOODS-North field, with the aim to understand its physical properties of stellar and dust emission, as well as the central active galactic nucleus (AGN) activity. Although it is shown that the source is likely an extremely dusty galaxy at high redshift, its exact position of submillimeter emission is unknown. Methods. We use NOEMA observation at 1.2 mm with subarcsecond resolution to resolve the dust emission, and precisely localize the counterparts at other wavelengths, which allows us to better constrain its stellar and dust spectral energy distribution (SED) as well as redshift. We carry out the new near-infrared (NIR) photometry of GH500.30 observed with HST, and perform panchromatic SED modelling from ultraviolet (UV)/optical to submillimeter. We derive the photometric redshift using both NIR and far-infrared (FIR) SED modeling, and place constraints on the stellar and dust properties such as stellar mass, age, dust attenuation, IR luminosity, and star-formation rate (SFR). The AGN properties are inferred from the X-ray spectral analysis and radio observations, and its contribution to the total IR luminosity is estimated from the broadband SED fittings using MAGPHYS. Results. With the new NOEMA interferometric imaging, we confirm that the source is a unique dusty galaxy. It has no obvious counterpart in the optical and even NIR images observed with HST at λ ≲ 1.4 μm. Photometric-redshift analyses from both stellar and dust SED suggest it to likely be at z ≳ 4, though a lower redshift at z ≳ 3.1 cannot be fully ruled out (at 90% confidence interval). Explaining its unusual optical-to-NIR properties requires an old stellar population (∼0.67 Gyr), coexisting with a very dusty ongoing starburst component. The latter is contributing to the FIR emission, with its rest-frame UV and optical light being largely obscured along our line of sight. If the observed fluxes at the rest-frame optical/NIR wavelengths were mainly contributed by old stars, a total stellar mass of ∼3.5 × 1011 M⊙ would be obtained. An X-ray spectral analysis suggests that this galaxy harbors a heavily obscured AGN with NH = 3.3+2.0−1.7 × 1023 cm−2 and an intrinsic 2–10 keV luminosity of Lx ∼ 2.6 × 1044 erg s−1, which places this object among distant type 2 quasars. The radio emission of the source is extremely bright, which is an order of magnitude higher than the star-formation-powered emission, making it one of the most distant radio-luminous dusty galaxies. Conclusions. The combined characteristics of the galaxy suggest that the source appears to have been caught in a rare but critical transition stage in the evolution of submillimeter galaxies, where we are witnessing the birth of a young AGN and possibly the earliest stage of its jet formation and feedback. ; This work is supported by the Chinese NSF through grant 11573001 and 11822301, National Basic Research Program 2015CB857005, the Sino-French LIA-Origin joint exchange program and Anhui Provincial NSF (1608085QA06). Y.Q.X. acknowledges support from the 973 Program (2015CB857004), NSFC-11473026, NSFC-11421303, and the CAS Frontier Science Key Research Program (QYZDJ-SSW-SLH006). D.L. acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 694343). Y.H. acknowledges support from NSFC-11773063.

This is an open access article under the CC BY license https://creativecommons.org/licenses/by/4.0 ; Fanaroff-Riley (FR) 0 radio galaxies compose a new class of radio galaxies, which are usually weaker but much more numerous than the well-established class of FR 1 and FR 2 galaxies. The latter classes have been proposed as sources of the ultra-high-energy cosmic rays (UHECRs) with energies reaching up to ∼1020 eV. Based on this conjecture, the possibility of UHECR acceleration and survival in an FR 0 source environment is examined in this work. In doing so, an average spectral energy distribution (SED) based on data from the FR 0 catalog (FR0CAT) is compiled. The resulting photon fields are used as targets for UHECRs, which suffer from electromagnetic pair production, photo-disintegration, photo-meson production losses, and synchrotron radiation. Multiple mechanisms are discussed to assess the UHECR acceleration probability, including Fermi-I order and gradual shear accelerations, and particle escape from the source region. This work shows that in a hybrid scenario, combining Fermi and shear accelerations, FR 0 galaxies can contribute to the observed UHECR flux, as long as Γj≳1.6, where shear acceleration starts to dominate over escape. Even in less optimistic scenarios, FR 0s can be expected to contribute to the cosmic-ray flux between the knee and the ankle. Our results are relatively robust with respect to the realized magnetic turbulence model and the speed of the accelerating shocks. © 2021 The Authors. ; This work acknowledges financial support from the Austrian Science Fund (FWF) under grant agreement number I 4144-N27 and from the Slovenian Research Agency -ARRS (project no. N10111). MB has for this project received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 847476. The views and opinions expressed herein do not necessarily reflect those of the European Commission. G.B. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration (NASA) and operated by the California Institute of Technology (CIT). Furthermore, part of this work is based on archival data, software, or online services provided by the Space Science Data Center (SSDC) via ASI. ; Peer reviewed

Full list of authors: Baldi, R. D.; Williams, D. R. A.; Beswick, R. J.; McHardy, I.; Dullo, B. T.; Knapen, J. H.; Zanisi, L.; Argo, M. K.; Aalto, S.; Alberdi, A.; Baan, W. A.; Bendo, G. J.; Fenech, D. M.; Green, D. A.; Klöckner, H. -R.; Körding, E.; Maccarone, T. J.; Marcaide, J. M.; Mutie, I.; Panessa, F.; Pérez-Torres, M. A.; Romero-Cañizales, C.; Saikia, D. J.; Saikia, P.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Uttley, P.; Brinks, E.; Corbel, S.; Martí-Vidal, I.; Mundell, C. G.; Pahari, M.; Ward, M. J. ; What determines the nuclear radio emission in local galaxies? To address this question, we combine optical [O iii] line emission, robust black hole (BH) mass estimates, and high-resolution e-MERLIN 1.5-GHz data, from the LeMMINGs survey, of a statistically complete sample of 280 nearby optically active (LINER and Seyfert) and inactive [H ii and absorption line galaxies (ALGs)] galaxies. Using [O iii] luminosity (L[O III]) as a proxy for the accretion power, local galaxies follow distinct sequences in the optical-radio planes of BH activity, which suggest different origins of the nuclear radio emission for the optical classes. The 1.5-GHz radio luminosity of their parsec-scale cores (Lcore) is found to scale with BH mass (MBH) and [O iii] luminosity. Below MBH ∼106.5 M⊙, stellar processes from non-jetted H ii galaxies dominate with Lcore ∝ MBH0.61 ± 0.33 and Lcore ∝ L[O III]0.79 ± 0.30. Above MBH ∼106.5 M⊙, accretion-driven processes dominate with Lcore ∝ MBH1.5-1.65 and Lcore ∝ L[O III]0.99-1.31 for active galaxies: radio-quiet/loud LINERs, Seyferts, and jetted H ii galaxies always display (although low) signatures of radio-emitting BH activity, with L1.5 GHz ≳ 1019.8 W Hz-1 and MBH ≳ 107 M⊙, on a broad range of Eddington-scaled accretion rates (m). Radio-quiet and radio-loud LINERs are powered by low-m discs launching sub-relativistic and relativistic jets, respectively. Low-power slow jets and disc/corona winds from moderately high to high-m discs account for the compact and edge-brightened jets of Seyferts, respectively. Jetted H ii galaxies may host weakly active BHs. Fuel-starved BHs and recurrent activity account for ALG properties. In conclusion, specific accretion-ejection states of active BHs determine the radio production and the optical classification of local active galaxies. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. ; This research was supported by a Newton Fund project, DARA (Development in Africa with Radio Astronomy), and awarded by the UK's Science and Technology Facilities Council (STFC) – grant reference ST/R001103/1. This research was supported by European Commission Horizon 2020 Research and Innovation Programme under grant agreement No. 730884 (JUMPING JIVE). FS acknowledges support from a Leverhulme Trust Research Fellowship. JHK acknowledges support from the European Union's Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement no. 721463 to the SUNDIAL ITN network, from the State Research Agency (AEI) of the Spanish Ministry of Science and Innovation and the European Regional Development Fund (FEDER) under the grant with reference PID2019-105602GB-I00, and from IAC project P/300724, financed by the Ministry of Science and Innovation, through the State Budget and by the Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community. IMV thanks the Generalitat Valenciana (funding from the GenT Project CIDEGENT/2018/021) and the MICINN (funding from the Research Project PID2019-108995GB-C22). AA and MAPT acknowledge support from the Spanish MCIU through grant PGC2018-098915-B-C21 and from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award for the Instituto de Astrofìsica de Andalucìa (SEV-2017-0709). BTD acknowledges financial support from grant 'Ayudas para la realización de proyectos de I + D para jóvenes doctores 2019' funded by Comunidad de Madrid and Universidad Complutense de Madrid under grant no. PR65/19-22417. ; Peer reviewed

We use 3213 active galactic nuclei (AGNs) from the XMM-XXL northern field to investigate the relation of AGN type with host galaxy properties. Applying a Bayesian method, we derive the hardness ratios, and through these the hydrogen column density (NH) for each source. We consider those with NH > 1021.5 cm−2 as absorbed sources (type 2). We examine the star formation rate (SFR) and the stellar mass (M*) distributions for both absorbed and unabsorbed sources. Our work indicates that there is no significant link between AGN type and these host galaxy properties. Next, we investigate whether the AGN power, as represented by its X-ray luminosity (LX) correlates with any deviation of the host galaxy's place from the so-called main sequence of galaxies, and we examine this separately for the obscured and the unobscured AGN populations. To take into account the effect of M* and redshift on SFR, we use the normalised SFR (SFRnorm). We find that the correlation between LX and SFRnorm follows approximately the same trend for both absorbed and unabsorbed sources, a result that favours the standard AGN unification models. Finally, we explore the connection between the obscuration (NH) and the SFR. We find that there is no relation between them, suggesting that obscuration is not related to the large-scale SFR in the galaxy. ; VAM and IG acknowledge support of this work by the PROTEAS II project (MIS 5002515), which is implemented under the "Reinforcement of the Research and Innovation Infrastructure" action, funded by the "Competitiveness, Entrepreneurship and Innovation" operational programme (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). This research is co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme "Human Resources Development, Education and Lifelong Learning 2014–2020" in the context of the project "Anatomy of galaxies: their stellar and dust content though cosmic time" (MIS 5052455). GM acknowledges ...

We present the first data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes galaxies which are active (low-ionization nuclear emission-line regions [LINER] and Seyfert) and quiescent (H II galaxies and absorption line galaxies, ALGs), which are reclassified based upon revised emission-line diagrams.We detect radio emission ≳0.2 mJy for 47/103 galaxies (22/34 for LINERS, 4/4 for Seyferts, 16/51 for HII galaxies, and 5/14 for ALGs) with radio sizes typically of ≲100 pc. We identify the radio core position within the radio structures for 41 sources. Half of the sample shows jetted morphologies. The remaining half shows single radio cores or complex morphologies. LINERs show radio structures more core-brightened than Seyferts. Radio luminosities of the sample range from 10 to 10 erg s: LINERs and HII galaxies show the highest and lowest radio powers, respectively, while ALGs and Seyferts have intermediate luminosities. We find that radio core luminosities correlate with black hole (BH) mass down to ~10 M, but a break emerges at lower masses. Using [OIII] line luminosity as a proxy for the accretion luminosity, active nuclei and jetted HII galaxies follow an optical Fundamental Plane of BH activity, suggesting a common disc-jet relationship. In conclusion, LINER nuclei are the scaled-down version of FR I radio galaxies; Seyferts show less collimated jets; HII galaxies may host weak active BHs and/or nuclear star-forming cores; and recurrent BH activity may account for ALG properties.© 2018 The Author(s). ; The authors thank the referee for a quick publication and the helpful comments from A. Laor and A. Capetti for the interpretation of the results. RDB and IMcH acknowledge the support of STFC under grant [ST/M001326/1] and IMcH thanks the Royal Society for the award of a Royal Society Leverhulme Trust Senior Research Fellowship. We acknowledge funding from the University of Southampton for a Mayflower studentship afforded to DW. EB and JW acknowledge support from the UK's Science and Technology Facilities Council [grant number ST/M503514/1] and [grant number ST/M001008/1], respectively. CGM acknowledges financial support from STFC. JHK acknowledges financial support from the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No. 721463 to the SUNDIAL ITN network, and from the Spanish Ministry of Economy and Competitiveness (MINECO) under grant number AYA2016-76219-P. DMF wishes to acknowledge funding from an STFC Q10 consolidated grant [ST/M001334/1]. BTD acknowledges support from a Spanish postdoctoral fellowship 'Ayudas para la atraccion del talento investigador. Modalidad 2: jovenes investigadores, financiadas por la Comunidad de Madrid' under grant number 2016-T2/TIC-2039. FP has received funding from the European Union's Horizon 2020 Programme under the AHEAD project (grant agreement No. 654215). We also acknowledge the Jodrell Bank Centre for Astrophysics, which is funded by the STFC. eMERLIN and formerly MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC. This publication has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 730562 [RadioNet].

Please read abstract in the article. ; DATA AVAILABILITY: The data underlying this article were accessed from the South African Radio Astronomy Observatory (SARAO; www.ska.ac.za). ; The National Research Foundation (NRF), SARAO. MP, SMR, the UK Science and Technology Facilities Council, the Oxford Hintze Centre for Astrophysical Surveys that is funded through generous support from the Hintze Family Charitable Foundation, the Rhodes University Centre for Radio Astronomy Techniques and Technologies (RATT), the European Union's Horizon 2020 research and innovation program under a Marie Skłodowska-Curie grant, the Inter-University Institute for Data Intensive Astronomy (IDIA), the South African Research Chairs Initiative of the NRF, the Glasstone Foundation, the Italian Ministry of Foreign Affairs and International Cooperation, the Science and Technology Foundation (FCT, Portugal), the Science and Technology Facilities Council (STFC), the South African Astronomical Observatory, the Bundesministerium für Bildung und Forschung (BMBF), the Inter-University Institute for Data Intensive Astronomy (IDIA) and the ERC-Stg DRANOEL. ; https://academic.oup.com/mnras ; hj2022 ; Physics

Ricci, C., et al. ; The merger of two or more galaxies can enhance the inflow of material from galactic scales into the close environments of active galactic nuclei (AGNs), obscuring and feeding the supermassive black hole (SMBH). Both recent simulations and observations of AGN in mergers have confirmed that mergers are related to strong nuclear obscuration. However, it is still unclear how AGN obscuration evolves in the last phases of the merger process. We study a sample of 60 luminous and ultra-luminous IR galaxies (U/LIRGs) from the GOALS sample observed by NuSTAR. We find that the fraction of AGNs that are Compton thick (CT; NH ≥ 1024 cm-2) peaks at 74+14 −19 per cent at a late merger stage, prior to coalescence, when the nuclei have projected separations (dsep) of 0.4-6 kpc. A similar peak is also observed in the median NH [(1.6 ± 0.5) × 1024 cm−2]. The vast majority (85+7 −9 per cent) of the AGNs in the final merger stages (dsep ≤ 10 kpc) are heavily obscured (NH ≥ 1023 cm−2), and the median NH of the accreting SMBHs in our sample is systematically higher than that of local hard X-ray-selected AGN, regardless of the merger stage. This implies that these objects have very obscured nuclear environments, with the NH ≥ 1023 cm−2 gas almost completely covering the AGN in late mergers. CT AGNs tend to have systematically higher absorption-corrected X-ray luminosities than less obscured sources. This could either be due to an evolutionary effect, with more obscured sources accreting more rapidly because they have more gas available in their surroundings, or to a selection bias. The latter scenario would imply that we are still missing a large fraction of heavily obscured, lower luminosity (L2−10 ≤ 1043 erg s−1) AGNs in U/LIRGs. ; LCH was supported by the National Key Research and Development Program of China (2016YFA0400702) and the National Science Foundation of China (11721303 and 11991052). CR acknowledges support from the Fondecyt Iniciacion grant 11190831. ET acknowledges support from CATA-Basal AFB-170002, FONDECYT Regular grant 1190818, ANID Anillo ACT172033, and Millennium Nucleus NCN19_058 (TITANs). FEB acknowledges support from ANID – Millennium Science Initiative Program – ICN12_009, CATA-Basal – AFB-170002, and FONDECYT Regular – 1190818 and 1200495. SA gratefully acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 789410). VU acknowledges funding support from NASA Astrophysics Data Analysis Program (ADAP) Grant 80NSSC20K0450. AMM acknowledges support from the National Science Foundation under grant number 2009416. KI acknowledges support by the Spanish MICINN under grant Proyecto/AEI/10.13039/501100011033 and 'Unit of excellence María de Maeztu 2020-2023' awarded to ICCUB (CEX2019-000918-M). PA acknowledges financial support from ANID Millennium Nucleus NCN19-058 (TITANS) and the Max Planck Society through a Partner Group. HI acknowledges support from JSPS KAKENHI Grant Number JP19K23462.

The cosmic history of the growth of supermassive black holes in galactic centres parallels that of star formation in the Universe. However, an important fraction of this growth occurs inconspicuously in obscured objects, where ultraviolet/optical/near-infrared emission is heavily obscured by dust. Since the X-ray flux is less attenuated, a high X-ray-to-optical flux ratio (fx/fo) is expected to be an efficient tool to find out these obscured accreting sources. We explore here via optical spectroscopy, X-ray spectroscopy and infrared photometry the most extreme cases of this population (those with fx/fo > 50, EXO50 sources hereafter), using a well-defined sample of seven X-ray sources extracted from the 2XMM catalogue. Five EXO50 sources (∼70 per cent of the sample) in the bright flux regime explored by our survey (f(2−10 keV) ≥ 1.5 × 10−13 erg cm−2 s−1) are associated with obscured AGN (NH > 1022 cm−2), spanning a redshift range between 0.75 and 1 and characterized by 2–10 keV intrinsic luminosities in the QSO regime (e.g. well in excess to 1044 erg s−1). We did not find compelling evidence of Compton thick active galacic nuclei (AGN). Overall, the EXO50 type 2 QSOs do not seem to be different from standard X-ray-selected type 2 QSOs in terms of nuclear absorption; a very high AGN/host galaxy ratio seems to play a major role in explaining their extreme properties. Interestingly, three out of five EXO50 type 2 QSO objects can be classified as extreme dust-obscured galaxies (EDOGs, f24 μm/fR ≥ 2000), suggesting that a very high AGN/host ratios (along with the large amount of dust absorption) could be the natural explanation also for a part of the EDOG population. The remaining two EXO50 sources are classified as BL Lac objects, having rather extreme properties, and which are good candidates for TeV emission. ; We acknowledge partial financial support from ASI grants (no. I/023/05/0, n. I/088/06/ and I/037/12/0) and from the Italian Ministry of Education, Universities and Research (PRIN2010-2011, grant no. 2010NHBSBE). The research leading to these results has received funding from the European Commission Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 267251 'Astronomy Fellowships in Italy' (AstroFIt). SM and FJC acknowledge financial support by the Spanish Ministry of Economy and Competitiveness through grants AYA2010-21490-C02-01 and AYA2012-31447 and from the ARCHES project, funded by the 7th Framework of the European Union (project no. 313146). AR acknowledges financial support by the Spanish Ministry of Economy and Competitiveness through grant AYA2012-31447. ; Peer Reviewed

Full list of authors: Baldi, R. D.; Williams, D. R. A.; McHardy, I. M.; Beswick, R. J.; Brinks, E.; Dullo, B. T.; Knapen, J. H.; Argo, M. K.; Aalto, S.; Alberdi, A.; Baan, W. A.; Bendo, G. J.; Corbel, S.; Fenech, D. M.; Gallagher, J. S.; Green, D. A.; Kennicutt, R. C.; Klöckner, H. -R.; Körding, E.; Maccarone, T. J.; Muxlow, T. W. B.; Mundell, C. G.; Panessa, F.; Peck, A. B.; Pérez-Torres, M. A.; Romero-Cañizales, C.; Saikia, P.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Varenius, E.; Ward, M. J.; Yates, J.; Uttley, P. ; We present the second data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 177 nearby galaxies from the Palomar sample, observed with the e-MERLIN array, as part of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies Sample (LeMMINGs) survey. Together with the 103 targets of the first LeMMINGs data release, this represents a complete sample of 280 local active (LINER and Seyfert) and inactive galaxies (H ii galaxies and absorption line galaxies, ALG). This large program is the deepest radio survey of the local Universe, ≳1017.6 W Hz-1, regardless of the host and nuclear type: we detect radio emission ≳0.25 mJy beam-1 for 125/280 galaxies (44.6 per cent) with sizes of typically ≲100 pc. Of those 125, 106 targets show a core which coincides within 1.2 arcsec with the optical nucleus. Although we observed mostly cores, around one third of the detected galaxies features jetted morphologies. The detected radio core luminosities of the sample range between ∼1034 and 1040 erg s-1. LINERs and Seyferts are the most luminous sources, whereas H ii galaxies are the least. LINERs show FR I-like core-brightened radio structures while Seyferts reveal the highest fraction of symmetric morphologies. The majority of H ii galaxies have single radio core or complex extended structures, which probably conceal a nuclear starburst and/or a weak active nucleus (seven of them show clear jets). ALGs, which are typically found in evolved ellipticals, although the least numerous, exhibit on average the most luminous radio structures, similar to LINERs. © 2020 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. ; The authors thank the anonymous referee for his/her helpful comments to improve the manuscript. AA and MAPT acknowledge support from the Spanish MCIU through grant PGC2018-098915-B-C21 and from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award for the Instituto de Astrof ' isica de Andalucia (SEV-2017-0709). BTD acknowledges support from a Spanish postdoctoral fellowship 'Ayudas 1265 para la atraccion del talento investigador. Modalidad 2: jovenes investigadores.' funded by Comunidad de Madrid under grant number 2016-T2/TIC-2039. BTD also acknowledges support from grant 'Ayudas para la realizaci on de proyectos de I + D para jovenes doctores 2019.' funded by Comunidad de Madrid and Universidad Complutense de Madrid under grant number PR65/19-22417. JHK acknowledges financial support from the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No. 721463 to the SUNDIAL ITN network, from the State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant 'The structure and evolution of galaxies and their central regions' with reference PID2019-105602GB-I00/10.13039/501100011033, and from IAC project P/300724, financed by the Ministry of Science and Innovation, through the State Budget and by the Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community. JSG thanks the University of Wisconsin-Madison and its Foundation for support of this research through his Rupple Bascom Professorship. FS acknowledges partial support from a Leverhulme Trust Research fellowship. CGM acknowledges support from the University of Bath and Jim and Hiroko Sherwin. e-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC, part of UK Research and Innovation. ; Peer reviewed