Asymmetrical structure of ionization and kinematics in the Seyfert galaxy NGC 5033

Research Projects
Organizational Units
Journal Issue
We present integral field spectroscopy of NGC 5033, a low luminosity Seyfert galaxy. The observations were made with INTEGRAL, a fiber based system operating at the WHT. The intensity map of the H emission line represents a spiral or ring-like pattern of HII regions. On the contrary, the [OIII] intensity map morphology is markedly anisotropic. The strong morphological differences imply that the [ OIII] emitters represent highly ionized gas illuminated by the central source. The [ OIII] map morphology is compatible with a biconical structure of ionization induced by strong extinction in the galaxy disc that also obscures half of the spheroidal stellar bulge. We identify the spectrum corresponding to the Seyfert 1 nucleus from the presence of H broad emission lines. This spectrum is located in a region where strong extinction is expected but exhibits the bluest spectral energy distribution. The Seyfert 1 nucleus seems to be off center with respect to the stellar rotation center. This result has been also found in other Seyfert galaxies and interpreted in terms of a past merger. The off centering could indicate the presence of nonsymmetric departures in the gravitational potential which could be fueling the active nucleus. The kinematics of the [ OIII] emitters show important deviations at a kpc scale with respect to the stellar velocity field and show features related to the asymmetrical morphology of the high ionization region.
© ESO 2005. The Isaac Newton Group of Telescopes (ING) operates the 4.2 m William Herschel Telescope on behalf of the Particle Physics and Astronomy Research Council (PPARC) of the United Kingdom and the Netherlands Organization for Scientific Research (NWO) of the Netherlands. The ING is located at the Roque de Los Muchachos Observatory, La Palma, Spain. Thanks to the anonymous referee for valuable comments and suggestions that have contributted to improve the final version of the paper. This paper has been supported by the Euro3D RTN “Promoting Integral Field Spectroscopy in Europe” (HPRN-CT-2002-00305) by the “Plan Andaluz de Investigación” (FQM-108) and by the “Secretaría de Estado de Política Científica y Tecnológica” (AYA2000-2046-C02-01). J.J.V. acknowledges support from the Consejería de Educación y Ciencia de la Junta de Andalucía, Spain. Some of the data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.
Unesco subjects
Arribas, S., Mediavilla, E., & Rasilla, J. L. 1991, ApJ, 369, 260 Arribas, S., & Mediavilla, E. 1993, ApJ, 410, 552 Arribas, S., Mediavilla, E., & García Lorenzo, B. 1996, ApJ, 463, 509 Arribas, S., Mediavilla, E., García Lorenzo, B., & del Burgo, C. 1997, ApJ, 490, 227 Arribas, S., Carter, D., Cavaller, L., et al. 1998, SPIE, 3355, 821 Arribas, S., Mediavilla, E., del Burgo, C., & García Lorenzo, B. 1999, ApJ, 511, 680 Battaner, E., Florido, E., & Sánchez Saavedra, M. L. 1990, A&A, 236, 1 Battaner, E., Mediavilla, E., Guijarro, A., Arribas, S., & Florido, E. 2003, A&A, 401, 67 Bingham, R. G., Gellatly, D. W., Jenkins, C. R., & Worswick, S. P. 1994, SPIE, 2198, 56 Bosma, A. 1981, AJ, 86, 1791 del Burgo, C., Mediavilla, E., & Arribas, S. 2000, ApJ, 540, 741 Curran, S. J., Polatidis, A. G., Aalto, S., & Booth, R. S. 2001, A&A, 373, 459 Ford, K. W., Rubin, V. C., & Roberts, M. S. 1971, AJ, 76, 22 Ho, L. C., Filippenko, A. V., & Sargent, W. L. W. 1997a, ApJ, 487, 568 Ho, L. C., Filippenko, A. V., & Sargent, W. L. W. 1997b, ApJ, 487, 579 Ho, L. C., Filippenko, A. V., & Sargent, W. L. W. 1997c, ApJS, 112, 315 Ho, L. C., & Ulvestad, J. S. 2001, ApJS, 133, 77 Kohno, K., Vila Vilaró, B., Sakamoto, S., et al. 2003, PASJ, 55, 103 Koratkar, A., Deustua, S. E., Heckman, T., et al. 1995, ApJ, 440, 132 Kormendy, J., & Richstone, D. 1995, ARA&A, 33, 581 MacKenty, J. W., Simkin, S. M., Griffiths, R. E., Ulvestad, J. S., & Wilson, A. S. 1994, ApJ, 435, 71 Mediavilla, E., & Arribas, S. 1993, Nature, 365, 420 Mediavilla, E., Arribas, S., García Lorenzo, B., & del Burgo, C. 1997, ApJ, 488, 682 Mediavilla, E., Arribas, S., García Lorenzo, B., & del Burgo, C. 1998, ApJ, 494L, 9 Terashima, Y., Kunieda, H., & Misaki, K. 1999, PASJ, 51, 277 Thean, A. H. C., Mundell, C. G., Pedlar, A., & Nicholson, R. A. 1997, MNRAS, 290, 15 van der Kruit, P. C., & Bosma, A. 1978, A&AS, 34, 259 Véron-Cetty, M.-P., & Véron, P. 2001, A&A, 374, 92 Wilson, A. S., Braatz, J. A., Heckman, T. M., Krolik, J. H., & Miley, G. K. 1993, ApJ, 419, L61 Whittle, M. 1992, APJS, 79, 49