PoS(10th EVN Symposium)081 http://pos.sissa.it/ ]), we have targeted a few additional 3 ∗ [email protected] [email protected] Speaker. Following the high detection rateSeyfert achieved galaxies by (Giroletti & EVN Panessa observations 2009, ApJL of 706, the 260, [ central regions of local sources from a complete sample. Weand have NGC detected 4138) at three both more 1.6 sources andof (NGC 5 the 3982, GHz sources NGC and was suitable present 3227, to preliminary include results. Areciboclues Moreover, in on the the the declination EVN compactness observations, of which provides the important emission region. ∗ Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. c

10th European VLBI Network Symposium andarrays EVN Users Meeting: VLBI andSeptember the 20-24, new 2010 generation of radio Manchester Uk Francesca Panessa INAF IASF, via Fosso del Cavaliere 100,E-mail: 00133 Rome, Italy Marcello Giroletti More discoveries of compact radio coresgalaxies in with Seyfert the EVN INAF Istituto di Radioastronomia via Gobetti 101, 40129 Bologna (Italy) E-mail: PoS(10th EVN Symposium)081 ]). 3 ,[ 1 Marcello Giroletti ]. Therefore, we 22Mpc) sample of 4 < d 5 mas). 2 × ] still made up a rather biased subset of the original sample, as 3 ]; however, it was necessary to request new dedicated observations ], typical beam 10 8 3 , 7 , 2 ], both from the literature and new observations. We find evidence in the 1 ]. It is then natural to wonder about the nature of this emission. In particular, 5 Combined optical and EVN images of Seyfert galaxies. Clockwise from top left: NGC 4051, It is a well established fact that radio quiet Active Galactic Nuclei (AGNs) are not radio The observational and physical properties determined for such sources were however quite The sources observed up to [ local Seyfert galaxies [ observations of the faintest sources werewith still VLBI missing. In yet; total, 8 13 of of them them have not have been a observed VLA detection in at least one frequency [ it is relevant to understand whetherysis it of is the compact high or diffuse. resolution radio We are properties carrying of out a an complete extensive distance anal- limited ( literature for the presence of compactmembers emission of from the published sample VLBI [ observationsfor of the the brightest majority of the weakEVN sources. from this As sample, a and start, successfully we detected observed compact 5 cores nuclei in of 4 Seyfert of galaxies them with (Fig. the silent: indeed, VLA observations reveal emissionluminosity at AGNs milliJansky [ level in most AGNs, even in low- different from target to target,case with even the with multi-components) presence and of of both flat compact and steep and spectra. resolved structures (in one 2. New observations Figure 1: 1. Background: recent VLBI observations of local Seyfert galaxies NGC 4388, NGC 5033, andEVN NGC observations 4501. at 1.6 Optical GHz ([ images from Sloan Digital Sky Survey, radio ones from More discoveries of compact radio cores in Seyfert galaxies with the EVN PoS(10th EVN Symposium)081 09pc. . 0 × in the radio). 1 19 − . Marcello Giroletti WHz 19 3 Jy. The addition of Arecibo is particularly relevant, as it µ 30 ∼ ]) making use of high resolution data. This will permit us to obtain a better 6 the visibility amplitudes and phases on baselines to Arecibo for one of the newly 2 Visibility amplitude and phase vs. time for baselines from Arecibo to Jodrell Bank (top panels), At a first look, based on pipeline calibrated data, three sources are clearly detected in at least Albeit preliminary, these results confirm that compact radio emission is present in most galac- observed sources (NGC 3227). Phasewhich coherence proves is that clearly the present target in ispreliminary these truely visibility transatlantic model compact. baselines, fit For indicates instance, that in the the source case is of at least NGC 3227 as at compact 5 as 0 GHz, a one of the two bands,is and at namely the NGC mJy 3982,provides NGC level, sensitive 3227, long with baselines. NGC 4138. The rms observations ofwere The the very cleaned five targets sensitive flux in but Giroletti density somewhat &on Panessa resolution (2009) the limited; sensitive indeed, but phase shortshow coherence baselines in was between Fig. best Effelsberg, detected Jodrell Bank, and Westerbork. We now 3. Preliminary results tic nuclei, even if their broad band luminosity is very low (as small as 10 Figure 2: Effelsberg (middle), and Westerbork (bottom). The target source is NGC 3227. performed new 1.6 andout 5 with GHz the observations EVN for inJodrell these Bank, June Westerbork, 8 Effelsberg, 2009, Onsala, targets. Medicina, with Torun, 1 Noto,telescope The plus for Gbps the the observations 300m recording sources Arecibo were rate. of radio suitable carried declination The and partecipating the telescopes new 40m were Yebes telescope at 5 GHz. It will be now possible toPanessa revisit et the connection al. to 2007, the [ X-ray properties (originally explored e.g. by More discoveries of compact radio cores in Seyfert galaxies with the EVN PoS(10th EVN Symposium)081 The X-ray and Marcello Giroletti 2009, ApJ, 706, L260, VLBA Identification of the 2002, A&A, 392, 53, 2005, AJ, 130, 936, Radio sources in low-luminosity active 2007, A&A, 467, 519, [arXiv:astro-ph/0701546] 4 The Parsec-Scale Radio Structure of NGC 1068 and the X-ray spectral survey with XMM-Newton of a complete 2004, ApJ, 613, 794, [arXiv:astro-ph/0406062] 2006, A&A, 446, 459, [arXiv:astro-ph/0509584] Radio Continuum Survey of an Optically Selected Sample of Nearby Seyfert The Faintest Seyfert Radio Cores Revealed by VLBI Radio Emission on Subparsec Scales from the Intermediate-Mass Black Hole 2006, ApJ, 646, L95, [arXiv:astro-ph/0606600] 2001, ApJS, 133, 77, [arXiv:astro-ph/0102506] in NGC 4395 [arXiv:astro-ph/0505141] radio connection in low-luminosity active nuclei Milliarcsecond Active Nucleus in the Seyfert Galaxy NGC 4151 sample of nearby Seyfert galaxies galactic nuclei. III. “AGNs” in a distance-limited sample of “LLAGNs” Galaxies Nature of the Nuclear Radio Source [arXiv:0910.5821] [arXiv:astro-ph/0207176] We acknowledge financial contribution from ASI-INAF I/088/06/0. The European VLBI Net- [1] Cappi, M., Panessa, F., Bassani, L., et al. [2] Gallimore, J. F., Baum, S. A., O’Dea, C. P. [8] Wrobel, J. M., Ho, L. C. [7] Ulvestad, J. S., Wong, D. S., Taylor, G. B., Gallimore, J. F., Mundell, C. G. [3] Giroletti, M., Panessa, F. [4] Ho, L. C., Ulvestad, J. S. [5] Nagar, N. M., Falcke, H., Wilson, A. S., Ulvestad, J. S. [6] Panessa, F., Barcons, X., Bassani, L., Cappi, M., Carrera, F. J., Ho, L. C., Pellegrini, S. work is a joint facilityfunded of by European, their national Chinese, research South councils. African and other radio astronomyReferences institutes More discoveries of compact radio cores in Seyfert galaxies with the EVN understanding of the exact location ofmechanisms the responsible radio for emission the and radio of and the X-ray interplay emission. between the physical Acknowledgments