CFHT/OASIS를 이용한 Seyfert 은하핵 연구

형식,김호일,한원용,Pierre Ferruit,류동수,이성재,이희원 한국천문학회 2001 天文學會報 Vol.26 No.1

GFHT/OASIS Observations of the Seyfert 2 Galaxy NGC 5728

손동훈,형식,Pierre Ferruit,이우백 한국천문학회 2006 天文學會報 Vol.31 No.1

STREAMING CIRCUMNUCLEAR GAS OF THE SEYFERT 2 GALAXY NGC 5728

손동훈,형식,이성재,Pierre Ferruit 한국천문학회 2009 Journal of The Korean Astronomical Society Vol.42 No.5

We investigated the circumnuclear region of the Seyfert 2 galaxy NGC 5728, using the CFHT 3.6 m OASIS [SⅡ], [OⅢ], & Hβ, spectral images complemented with the IUE spectra. The physical condition of the circumnuclear zone has been derived: the gas density (indicated by [SⅡ], 6716/31 ratio) around the C core is generally similar to that around the NW core, i.e., ~ 500 cm-3. However, there appears to be evidence of a higher density shell in front of the NW core, ~10^4 cm -3 at -250kms. The IUE SiⅢ]1892/CⅢ] 1909 ratio implies a possible presence of a broad emission region of gas densities of ~1010 cm-3. The SE cone and surrounding area show several prominent features, while the NW cone does not show any particular structure: we identified three prominent blobs in the SE cone and one possible candidate in the NW cone. The outflow activities exist within the relatively large conic opening angle. We discussed the possibility of inflow or outflow activities of blobs found in the circumnuclear region of \astrobj. The gas around two cores, two cones, and several blobs, is likely to be excited by the AGN hot source(s).

시이펏 은하 NGC 5728의 OASIS 분광 영상

형식,손동훈,P. Ferruit,이우백 한국지구과학회 2006 한국지구과학회지 Vol.27 No.5

The distribution and kinematic information of the continuum, Hα, Hβ, [O III], & [N II] images based onspectroscopic data secured with the OASIS at the Hawaii CFHT 3.6m telescope have been analyzed to study the physicalcharacteristics of NGC 5728. The three bright regions-northwestern knot, southeastern knot, and the nucleus-exist within a15"× 12" sky area which seem to indicate gas flows along the northwestern or western direction from the nucleus. Wefind that the center of a 10" diameter ring is at the northwestern knot, not at the galactic center. To further analyze theformation mechanism of such a ring, the kinematics of the nucleus and knot have been studied and the central structureof the Active Galactic Nuclei has been investigated by comparing various emission images.Seyfert Galaxy, Active Galactic Nuclei, spectroscopic observation, NGC 5728. . : CFHT ... 3.6 m .... ... OASIS .... .... .. ..... continuum, Hα, Hβ, [O III],[N II] .. ... ... .. ... NGC 5728. ... ... ..... . NGC 5728. .... NLR .... .... . 15"× 12" .. ... 3.. .. .. (NW knot, SE knot, nucleus). .... .. , .. .(nucleus). .... ...... .... ... ... .... ... ..... ... .. 10". ring. ..... .. NW knot. ... ..... .... ... ..... . ... ... ... .. ... .. .... ... .. knot. .... ... .... ... , ... .... ... .... ...... .. .

The kinematics of the Seyfert 2 galaxy NGC 5728 circumnuclear region

Son, D.-H.,Hyung, S.,Ferruit, P.,Pé,contal, E.,Lee, W.-B. Blackwell Publishing Ltd 2009 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.395 No.2

<P>ABSTRACT</P><P>We secured spectral images of the circumnuclear, 12 × 10 arcsec<SUP>2</SUP> region of the Seyfert 2 galaxy NGC 5728 with the Optically Adaptive System for Imaging Spectroscopy at the Canada–France–Hawaii Telescope 3.6-m telescope. The radial velocity distribution of the two bright zones, main central (C) core and north-west (NW) core, and strategically important points along the position angles, PA 33°, 90°, 123° and 143°, are analysed. The large-scale reconstructed monochromatic images of the Hα, Hβ, [O <SMALL>III</SMALL>] and [N <SMALL>II</SMALL>] lines show a bipolar morphology along PA ∼ 123°. The prominent elliptical ring is seen in the Hα and Hβ monochromatic images. Our analysis implies that this ring is rotating in the same clockwise direction as that of the galactic disc; this elliptical ring is in fact a projected result of a circular ring of radius ∼5.4 arcsec, with <I>i</I>∼ 50° (nearly aligned with the host galactic plane).</P><P>We used the [O <SMALL>III</SMALL>]5007 line profiles for a detailed analysis of kinematics in the circumnuclear region of the NGC 5728. The [O <SMALL>III</SMALL>]5007 line profiles reveal distinct kinematical structures. (1) The strongest component of Doppler peaks: two core components, consisting of the receding main C-core and the approaching NW-core with the radial velocities, <I>V</I><SUB>r</SUB>≃+250 and −240 (or −250) km s<SUP>−1</SUP>, respectively. These two cores consist of a roughly spherically symmetric distribution of the gas with radii of <I>r</I>∼ 1.0 arcsec (at <I>V</I><SUB>r</SUB>≃+240 km s<SUP>−1</SUP>) and 0.9 arcsec (at <I>V</I><SUB>r</SUB>≃−240 km s<SUP>−1</SUP>), respectively. Hints of the presence of inflows around these cores are observed. (2) The next strong line profile component: this component corresponds to the bipolar cone aligned PA ∼ 123°. (3) The reverse S-shaped kinematical boundary which runs through the double-peaked zone of 6–7 arcsec long in the galactic major axis direction is likely to be caused by a combination of the disc rotation of the host galaxy and the revolution of the two central cores.</P>

STREAMING CIRCUMNUCLEAR GAS OF THE SEYFERT 2 GALAXY NGC 5728

Son, Dong-Hoon,Hyung, Siek,Lee, Seong-Jae,Ferruit, Pierre The Korean Astronomical Society 2009 Journal of The Korean Astronomical Society Vol.42 No.5

We investigated the circumnuclear region of the Seyfert 2 galaxy NGC 5728, using the CFHT 3.6 m OASIS $[S_{II}]$, $[O_{III}]$ & $H\beta$ spectral images complemented with the IUE spectra. The physical condition of the circumnuclear zone has been derived: the gas density (indicated by $[S_{II}]$6716/31 ratio) around the C core is generally similar to that around the NW core, i.e., $\sim500cm^{-3}$. However, there appears to be evidence of a higher density shell in front of the NW core, $\sim10^4cm^{-3}$ at -250 km $s^-1$. The IUE $Si_{III}$]1892/$C_{III}$]1909 ratio implies a possible presence of a broad emission region of gas densities of $\sim10^{10}cm^{-3}$. The SE cone and surrounding area show several prominent features, while the NW cone does not show any particular structure: we identified three prominent blobs in the SE cone and one possible candidate in the NW cone. The outflow activities exist within the relatively large conic opening angle. We discussed the possibility of inflow or outflow activities of blobs found in the circumnuclear region of NGC 5728. The gas around two cores, two cones, and several blobs, is likely to be excited by the AGN hot source(s).

STREAMING CIRCUMNUCLEAR GAS OF THE SEYFERT 2 GALAXY NGC 5728

Dong-Hoon Son,Siek Hyung,Seong-Jae Lee,Pierre Ferruit 한국천문학회 2009 Journal of The Korean Astronomical Society Vol.42 No.4

We investigated the circumnuclear region of the Seyfert 2 galaxy NGC 5728, using the CFHT 3.6 m OASIS [S ΙΙ], [O ΙΙΙ] & Hβ, spectral images complemented with the IUE spectra. The physical condition of the circumnuclear zone has been derived: the gas density (indicated by [S ΙΙ]6716/31 ratio) around the C core is generally similar to that around the NW core, i.e., ~ 500 cm-3. However, there appears to be evidence of a higher density shell in front of the NW core, ~ 104 cm -3 at -250 km s-1. The IUE Si ΙΙΙ]1892/C ΙΙΙ]1909 ratio implies a possible presence of a broad emission region of gas densities of ~1010 cm-3. The SE cone and surrounding area show several prominent features, while the NW cone does not show any particular structure: we identified three prominent blobs in the SE cone and one possible candidate in the NW cone. The outflow activities exist within the relatively large conic opening angle. We discussed the possibility of inflow or outflow activities of blobs found in the circumnuclear region of NGC 5728. The gas around two cores, two cones, and several blobs, is likely to be excited by the AGN hot source(s).