(2003 July 06 UPDATE)


Nishiura's Researches




Observational Extragalactic Astronomy


I have two themes,

[ A ] : Compact Groups of Galaxies

Compact Groups of Galaxies are very small, isolated, and high number density systems consisted of from a few to a several galaxies. Their sizes are similar to those of isolated galaxies and their galaxy number densities are also similar to those of galaxy clusters. Compact Groups of Galaxies are best target to investigate how galaxy environments depending on their formations and evolutions.

[ B ] : Active Galactic Nuclei (AGNs).

There are many galaxies which have very very luminous nuclei. We call such galaxies as "Active Galaxies" and such nuclei as "Active Galactic Nuclei (AGNs)". The Active Galactic Nuclei include Quasi-Stellar Objects (Quasars : QSOs), Radio Galaxies, Seyfert Galaxies, Low Ionization Narrow Emission line Regions (LINERs), Blazers, BL Lacertae (BL Lac) Objects. Furthermore Active Galaxies include UltraLuminous InfraRed Galaxies (ULIRGs), Starburst Galaxies. How process does they have to obtain such a high energy ?.





My Research Works

------------ Refereed Journal ------------


``Discovery of the Dust Trail of the Stardust Comet Sample Return Mission Target: 81P/Wild 2''
Ishiguro, M., Kwon, S. M., Sarugaku, Y., Hasegawa, S., Usui, F., Nishiura, S., Nakada, Y., & Yano, H.
2003, The Astrophysical Journal, 589, L101.


``Optical Imaging of the Radiant Points of Leonids during the 2001 Storm with the 105cm Kiso Schmidt Telescope''
Nishiura, S., Ohnishi, K., Dobashi, K., Watanabe, J., Miyata, T., & Nakada, Y.
2002, Pablications of the Astronomical Society of Japan, 54, L83


``Effects of a Burst of Formation of First-Generation Stars on the Evolution of Galaxies''
Shioya, Y., Taniguchi, Y., Murayama, T., Nishiura, S., Nagao, T., & Kakazu, Y.
2002, The Astrophysical Journal, 576, 36.


``A Multi-band Photometric Study of Tidal Debris in A Compact Group of Galaxies: Seyfert's Sextet''
Nishiura, S., Shioya, Y., Murayama, T., Sato, Y., Nagao, T., Taniguchi, Y. & Sanders, D. B.
2002, Pablications of the Astronomical Society of Japan, 54, in press


``A Shock-induced Pair of Superbubbles in the High-Redshift Powerful Radio Galaxy MRC 0406-244''
Taniguchi, Y., Ohyama, Y., Murayama, T., Yoshida, M., Kashikawa, N., Iye, M., Aoki, K., Sasaki, T., Kosugi, G., Takata, T., Saito, Y., Kawabata, K. S., Sekiguchi, K., Okita, K., Shimizu, Y., Inata, M., Ebizuka, N., Ozawa, T., Yadomaru, Y., Taguchi, H., Shioya, Y., Nishiura, S., Sudou, H., Nagao, T., Noda, S., Koyama, Y., Kakazu, Y., Ajiki, M., Fujita, S. S., Kobayashi, R. R.
2001, Astrophysical Journal, 559, L9


``Deep Optical Imaging of A Compact Group of Galaxies, Seyfert's Sextet''
Nishiura, S., Murayama, T., Shimada, M., Sato, Y., Nagao, T., Molikawa, K., Taniguchi, Y. & Sanders, D. B.
2000, Astronomical Journal, 120, 2355 Abstract


``A Dynamical Study of Galaxies in The Hickson Compact Groups''
Nishiura, S., Shimada, M., Ohyama, Y., Murayama, T., & Taniguchi, Y.
2000, Astronomical Journal, 120, 1691 Abstract


``The Nuclear Activity of the Galaxies in the Hickson Compact Groups''
Shimada, M., Ohyama, Y., Nishiura, S., Murayama, T., & Taniguchi, Y.
2000, Astronomical Journal, 119, 2664 Abstract


``Discovery of a Low Surface Brightness Object Near Seyfert's Sextet''
Murayama, T., Nishiura, S., Nagao, T., Sato, Y., Taniguchi, Y., \& Sanders, D. B.
2000, Astronomical Journal, 119, 1691


``Optical versus Mid-infrared Spectroscopic Classification of Ultraluminous Infrared Galaxies''
Taniguchi, Y., Yoshino, A., Ohyama, Y., & Nishiura, S.
1999, Astrophysical Journal, 514, 660


``Dynamical Mass of Type 2 Seyfert Nuclei''
Nishiura, S., & Taniguchi, Y.
1998, Astrophysical Journal, 499, 134


``A Geometrical Relationship between Broad-Line Clouds and an Accretion Disk around Active Galactic Nuclei''
Nishiura, S., Murayama, T., & Taniguchi, Y.
1998, Pablications of the Astronomical Society of Japan, 50, 31


``Unusual Emission-Line Regions in the Tidal Arm of NGC 7318B in Stephan's Quintet''
Ohyama, Y., Nishiura, S., Murayama, T., & Taniguchi, Y.
1998, Astrophysical Journal Letters, 492, 250



------------ Proceeding etc. ------------


``Galaxy School 2003 - for five years and next''
Nishiura, S.
2003, The Astronomical Herald (ISSN 0374-2466), 96, 7.


``Deep Optical Imaging of the Compact Group ``Seyfert's Sextet''''
Nishiura, S.
2000, Small Galaxy Groups., Proceedings of IAU Colloquium 174, eds Valtonen, M. J., & Flynn, C., ASP Conference Series 209, P. 100


``An Unusual Bubble in the Tidal Arm of NGC7318B in Stephan's Quintet''
Ohyama, Y., Nishiura, S., Murayama,T., & Taniguchi, Y.
1999, Wolf-Rayet Phenomena in Massive Stars and Starburst Galaxies., Proceedings of IAU Symposium 193, eds Karel A. van der Hucht, Gloria Koenigsberger, and Philippe R. J. Eenens., Astronomical Society of the Pacific , p.612


``A K-Band Luminosity Function of Hickson Compact Groups of Galaxies''
Nishiura, S., Murayama,T., Taniguchi, Y., Sato, Y., & Sanders, D. B.
1999, Galaxy Interactions at Low and High Redshift., Proceedings of IAU Symposium 186, eds Barnes, J. E. and Sanders, D.B., p.415


``Efficient Star-Formation in the Tidal Arms of the Stephan's Quintet Group of Galaxies''
Ohyama, Y., Nishiura, S., Murayama,T., & Taniguchi, Y.
1999, Galaxy Interactions at Low and High Redshift., Proceedings of IAU Symposium 186, eds Barnes, J. E. and Sanders, D.B., p.416


``Nuclear Activity in the Hickson Compact Groups of Galaxies''
Shimada, M., Nishiura, S., Ohyama, Y., Murayama,T., & Taniguchi, Y.
1999, Galaxy Interactions at Low and High Redshift., Proceedings of IAU Symposium 186, eds Barnes, J. E. and Sanders, D.B., p.418


``KISO H-alpha imaging observations of nearby galaxies''
Hasegawa, T., Sakamoto, S., Nishiura, S., Ohyama, Y., & Sofue, Y.
1998, Publications Astronomical Society of Australia, 15, 149





Astronomical Institute, Tohoku University (Written in Only Japanese)

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