@article {231, title = {{Multiple AGN in the crowded field of the compact group SDSS J0959+1259}}, journal = {MNRAS}, volume = {453}, year = {2015}, pages = {214-221}, keywords = {galaxies: active, galaxies: interactions, galaxies: Seyfert, X-rays: galaxies}, doi = {10.1093/mnras/stv1623}, url = {http://adsabs.harvard.edu/abs/2015MNRAS.453..214D}, author = {De Rosa, A. and Bianchi, S. and Bogdanovi{\'c}, T. and Decarli, R. and Herrero-Illana, R. and Husemann, B. and Komossa, S. and Kun, E. and Loiseau, N. and Paragi, Z. and P{\'e}rez-Torres, M. and Piconcelli, E. and Schawinski, K. and Vignali, C.} } @article {218, title = {{Molecular line emission in NGC 1068 imaged with ALMA. I. An AGN-driven outflow in the dense molecular gas}}, journal = {\aap}, volume = {567}, year = {2014}, pages = {A125}, keywords = {galaxies: individual: NGC 1068, galaxies: ISM, galaxies: kinematics and dynamics, galaxies: nuclei, galaxies: Seyfert, radio lines: galaxies}, doi = {10.1051/0004-6361/201423843}, author = {Garcia-Burillo, S. and Combes, F. and Usero, A. and Aalto, S. and Krips, M. and Viti, S. and Alonso-Herrero, A. and Hunt, L.~K. and Schinnerer, E. and Baker, A.~J. and Boone, F. and Casasola, V. and Colina, L. and Costagliola, F. and Eckart, A. and Fuente, A. and Henkel, C. and Labiano, A. and Mart{\'\i}n, S. and Marquez, I. and Muller, S. and Planesas, P. and Ramos Almeida, C. and Spaans, M. and Tacconi, L.~J. and van der Werf, P.~P.} } @article {2014A\&A...567A.125G, title = {{Molecular line emission in NGC 1068 imaged with ALMA. I. An AGN-driven outflow in the dense molecular gas}}, journal = {Astronomy and Astrophysics}, volume = {567}, year = {2014}, month = {jul}, pages = {A125}, abstract = {
Aims: We investigate the fueling and the feedback of star formation and nuclear activity in NGC 1068, a nearby (D = 14 Mpc) Seyfert 2 barred galaxy, by analyzing the distribution and kinematics of the molecular gas in the disk. We aim to understand if and how gas accretion can self-regulate.
Methods: We have used the Atacama Large Millimeter Array (ALMA) to map the emission of a set of dense molecular gas (n(H$_{2}$) {\sime} 10$^{5 - 6}$ cm$^{-3}$) tracers (CO(3-2), CO(6-5), HCN(4-3), HCO$^{+}$(4-3), and CS(7-6)) and their underlying continuum emission in the central r \~{} 2 kpc of NGC 1068 with spatial resolutions \~{}0.3{\Prime} - 0.5{\Prime} (\~{}20-35 pc for the assumed distance of D = 14 Mpc).
Results: The sensitivity and spatial resolution of ALMA give an unprecedented detailed view of the distribution and kinematics of the dense molecular gas (n(H$_{2}$) {\ge} 10$^{5 - 6}$cm$^{-3}$) in NGC 1068. Molecular line and dust continuum emissions are detected from a r \~{} 200 pc off-centered circumnuclear disk (CND), from the 2.6 kpc-diameter bar region, and from the r \~{} 1.3 kpc starburst (SB) ring. Most of the emission in HCO$^{+}$, HCN, and CS stems from the CND. Molecular line ratios show dramatic order-of-magnitude changes inside the CND that are correlated with the UV/X-ray illumination by the active galactic nucleus (AGN), betraying ongoing feedback. We used the dust continuum fluxes measured by ALMA together with NIR/MIR data to constrain the properties of the putative torus using CLUMPY models and found a torus radius of 20$^{+6}$$_{-10}$pc. The Fourier decomposition of the gas velocity field indicates that rotation is perturbed by an inward radial flow in the SB ring and the bar region. However, the gas kinematics from r \~{} 50 pc out to r \~{} 400 pc reveal a massive (M$_{mol}$\~{} 2.7$^{+0.9}$$_{-1.2}$ {\times} 10$^{7}$ M$_{\&sun;}$) outflow in all molecular tracers. The tight correlation between the ionized gas outflow, the radio jet, and the occurrence of outward motions in the disk suggests that the outflow is AGN driven.
Conclusions: The molecular outflow is likely launched when the ionization cone of the narrow line region sweeps the nuclear disk. The outflow rate estimated in the CND, dM/dt\~{} 63$^{+21}$$_{-37}$ M$_{\&sun;}$ yr$^{-1}$, is an order of magnitude higher than the star formation rate at these radii, confirming that the outflow is AGN driven. The power of the AGN is able to account for the estimated momentum and kinetic luminosity of the outflow. The CND mass load rate of the CND outflow implies a very short gas depletion timescale of {\l}e}1 Myr. The CND gas reservoir is likely replenished on longer timescales by efficient gas inflow from the outer disk. Based on observations carried out with ALMA in Cycle 0.}, keywords = {galaxies: individual: NGC 1068, galaxies: ISM, galaxies: kinematics and dynamics, galaxies: nuclei, galaxies: Seyfert, radio lines: galaxies}, doi = {10.1051/0004-6361/201423843}, url = {http://adsabs.harvard.edu/abs/2014A\%26A...567A.125G}, author = {S. Garc{\'\i}a-Burillo and Combes, F. and Usero, A. and Aalto, S. and Krips, M. and Viti, S. and Alonso-Herrero, A. and Hunt, L.~K. and Schinnerer, E. and Baker, A.~J. and Boone, F. and Casasola, V. and Colina, L. and F. Costagliola and Eckart, A. and Fuente, A. and Henkel, C. and Labiano, A. and Mart{\'\i}n, S. and Marquez, I. and Muller, S. and Planesas, P. and Ramos Almeida, C. and Spaans, M. and Tacconi, L.~J. and van der Werf, P.~P.} } @article {2014A\&A...566A..15V, title = {{The radio core structure of the luminous infrared galaxy NGC 4418. A young clustered starburst revealed?}}, journal = {Astronomy and Astrophysics}, volume = {566}, year = {2014}, month = {jun}, pages = {A15}, abstract = {Context. The galaxy NGC 4418 contains one of the most compact obscured nuclei within a luminous infrared galaxy (LIRG) in the nearby Universe. This nucleus contains a rich molecular gas environment and an unusually high ratio of infrared-to-radio luminosity (q-factor). The compact nucleus is powered by either a compact starburst or an active galactic nucleus (AGN).
Aims: The aim of this study is to constrain the nature of the nuclear region (starburst or AGN) within NGC 4418 via very-high-resolution radio imaging.
Methods: Archival data from radio observations using the European Very Long Baseline Interferometry Network (EVN) and Multi-Element Radio Linked Interferometer Network (MERLIN) interferometers are imaged. Sizes and flux densities are obtained by fitting Gaussian intensity distributions to the image. The average spectral index of the compact radio emission is estimated from measurements at 1.4 GHz and 5.0 GHz.
Results: The nuclear structure of NGC 4418 visible with EVN and MERLIN consists of eight compact ({\l}t}49 mas i.e. {\l}t}8 pc) features spread within a region of 250 mas, i.e. 41 pc. We derive an inverted spectral index {$\alpha$} {\ge} 0.7 (S$_{nu}$ {\prop} {$ν$}$^{alpha}$) for the compact radio emission.
Conclusions: Brightness temperatures {\gt}10$^{4.8}$ K indicate that these compact features cannot be HII-regions. The complex morphology and inverted spectrum of the eight detected compact features is evidence against the hypothesis that an AGN alone is powering the nucleus of NGC 4418. The compact features could be super star clusters with intense star formation, and their associated free-free absorption could then naturally explain both their inverted radio spectrum and the low radio-to-IR ratio of the nucleus. The required star formation area density is extreme, however, and close to the limit of what can be observed in a well-mixed thermal/non-thermal plasma produced by star formation, and is also close to the limit of what can be physically sustained.}, keywords = {galaxies: individual: NGC 4418, galaxies: Seyfert, galaxies: star formation}, doi = {10.1051/0004-6361/201323303}, url = {http://adsabs.harvard.edu/abs/2014A\%26A...566A..15V}, author = {Varenius, E. and Conway, J.~E. and Mart{\'\i}-Vidal, I. and Aalto, S. and Beswick, R. and F. Costagliola and Kl{\"o}ckner, H.-R.} } @article {219, title = {{The radio core structure of the luminous infrared galaxy NGC 4418. A young clustered starburst revealed?}}, journal = {\aap}, volume = {566}, year = {2014}, pages = {A15}, keywords = {galaxies: individual: NGC 4418, galaxies: Seyfert, galaxies: star formation}, doi = {10.1051/0004-6361/201323303}, author = {Varenius, E. and Conway, J.~E. and Mart{\'\i}-Vidal, I. and Aalto, S. and Beswick, R. and Costagliola, F. and Kl{\"o}ckner, H.-R.} } @article {2013MNRAS.435.2335B, title = {{The NGC 3341 minor merger: a panchromatic view of the active galactic nucleus in a dwarf companion}}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {435}, year = {2013}, month = {nov}, pages = {2335-2344}, abstract = {We present X-ray (Chandra), radio (Expanded Very Large Array and European VLBI Network) and archival optical data of the triple-merging system in NGC 3341. Our panchromatic analysis confirms the presence of a Seyfert 2 active galactic nucleus (AGN) in NGC 3341B, one of the secondary dwarf companions. On the other hand, the nucleus of the primary galaxy, consistent with a star-forming region of a few solar masses per year, and NGC 3341C are very unlikely to host an AGN. We therefore suggest that NGC 3341 is an exceptional example of an AGN triggered in the satellite galaxy of a minor-merging system. The existence of such a system can have important implications in the models of hierarchical growth of structures. Further observational and theoretical efforts on NGC 3341 and potentially similar sources are needed in order to understand the role of minor mergers on the onset of AGN activity, and in the evolution of massive galaxies.}, keywords = {galaxies: active, galaxies: interactions, galaxies: Seyfert, X-rays: individual: NGC 3341}, doi = {10.1093/mnras/stt1459}, url = {http://adsabs.harvard.edu/abs/2013MNRAS.435.2335B}, author = {Bianchi, S. and Piconcelli, E. and M. A. P{\'e}rez-Torres and Fiore, F. and La Franca, F. and Mathur, S. and Matt, G.} }