Masahiro Suganuma ( National Astronomical Observatory of Japan )

Presentation on theme: "Masahiro Suganuma ( National Astronomical Observatory of Japan )"— Presentation transcript:

1 Masahiro Suganuma ( National Astronomical Observatory of Japan )
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. “Reverberation Measurements of the Inner Radius of the Dust Torus in Nearby Seyfert 1 Galaxies’’ Masahiro Suganuma ( National Astronomical Observatory of Japan ) with MAGNUM (Multicolor Active Galactic NUclei Monitoring) group: Y. Yoshii, T. Minezaki, H. Tomita, T. Aoki, S. Koshida (University of Tokyo) Y. Kobayashi (National Astronomical Observatory of Japan) K. Enya (Japan Aerospace Exploration Agency) B. A. Peterson (Australian National University) - I’ll be talking about recent results of our dust reverberation study for nearby Seyfert1 Galaxies. ~~~~~~~~~~~~~~ - This study was collaborated with these members of MAGNUM group.

2 Outline: Introduction: Principles of dust reverberation method
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Outline: Introduction: What determine the inner radius of the dust torus ? Where is the inner border of the dust torus located being compared with other regions of AGNs ? Principles of dust reverberation method Monitoring observations and results Simultaneous photometric monitoring in Opt. / NIR Clear lag time detections between V-band var. and K-band var. Discussion - This presentation is divided into these four parts. ~~~~~~~~~~~~~~~~~~~~~~~ - First for an introduction, I’d like to clear our focus of this study. - Second, I will explain the principle of dust reverberation method of observation. - Then, I will present our observations and results. - Finally, I’ll discuss about our results from these two points of view.

3 Main Focus 1. What determine the inner radius?
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Main Focus Urry & Padovani (1995) 1. What determine the inner radius? Sublimation temperature of grains (graphite) = const. -> The radius should to be proportional to L0.5UV - On this first slide, I will describe our focus of this study. ~~~~~~~~~~~~~~~~~~~~~~~~ - This is a schematic viewgraph of AGNs we generally believe. - There seems to exist a dust region with a donuts-like shape around the central engine and broad-emission line region. - However, we haven’t seen this by spatially resolved images!! - We break down our focus into two questions. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - The first question is “What determine the inner radius?” - And second question is “Where is the inner border located being compared with other regions?” - For the first question, if sublimation temperature of dust grains are constant, the inner radius of the torus should be proportional to square-root of UV luminosity of the central engine. - For the second question, unified scheme of AGNs expect it to be outside of the broad-line region. - To answer for these questions, we use a thermal reverberation technique of observation. ~~~~~~~~~~~~~~~~~~~~~~ 2. Where is the border located being compared with other regions? Unified scheme of AGNs expect it to be outside of BLR Thermal dust reverberation can resolve the inner border of dust torus by means of differences of flux variations between optical and near-infrared.

4 Thermal dust reverberation of AGNs.
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Thermal dust reverberation of AGNs. Power-law Black-body (T= K) V-band K-band Flux Time lag time t NIR UV/Opt. NIR c t - On this second slide, I will explain the principle of thermal dust reverberation of AGNs. ~~~~~~~~~~~~~~~~ - This figure shows a typical spectrum shape of type 1 AGNs in optical to near-infrared. ~~~~~~~~~~~~~~ - The optical emission, the longer wavelength tail of power-law component, comes from the central engine. - On the other hand, near-infrared emission is thought to be thermally originated from hot dust surrounding the central engine. - The dust grains are irradiated by the central engine up to near their sublimation temperature of about a thousand and hundreds of Kelvin. - So, if we monitor an AGN in optical and near-infrared simultaneously, we will observe lag time between the variation of them. ~~~~~~~~~~~~ - The lag time should correspond to the light-travel time of the inner radius of the dust torus.

5 Monitoring Observation of AGNs
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Xi’an Tokyo Honolulu Monitoring Observation of AGNs 2-m optical / infrared robotic telescope (since Aug. 2000) Maui Island Top of Mt. Haleakala (3050m) Los - Next, I will briefly present our MAGNUM observatory. ~~~~~~~~~~~~~~~~~ - In Hawaiian island of Maui, on the top of Mt. Haleakala, three thousand meters high, we prepared a 2-m optical and infrared robotic telescope that doesn’t have any operators or engineers staying in Hawaii. ~~~~~~~~~~~~~ - We only watch from Tokyo how the observations are carried out. - We started monitoring observations for several AGNs in two-thousand one.

6 First Result NGC 4151 Vnuc=15.4mag 1242 km/s (3KCMB) V-band K-band
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. First Result NGC 4151 Vnuc=15.4mag 1242 km/s (3KCMB) Minezaki et al. (2004) ApJL, 600, 35 Lag time = days +2 -3 V-band K-band - Now, I’ll show you the first result of our observations. ~~~~~~~~~~~~~ - This is NGC forty-one fifty-one, a nearby bright Seyfert 1 galaxy. - This graph shows the observed light curves for V-band and for K-band. - The shapes of these two curves are similar, but K-band one delays after V-band one. - Our cross-correlation analysis measured the lag time to be about forty-eight days. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

7 Succeeding results NGC 5548 DSS R-band image Vnuc=15.4mag
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Succeeding results NGC 5548 Vnuc=15.4mag 5359 km/s (3KCMB) t = days t = days t = days - Moving on to the next slide, I will show you the succeeding results for other several objects. ~~~~~~~~~~~~~~~~~~~~~~~~~~ - This is NGC fifty-five forty-eight. - This next graph shows the observed light curves for this object. ~~~~~~~~~~~~~~~~~ - If we shift K light curve ahead by about fifty days, these peaks and valleys of two curves coincide with each others. DSS R-band image

8 NGC 4051 DSS Bj-band image Vnuc=15.2mag 924 km/s (3KCMB)
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. NGC 4051 Vnuc=15.2mag 924 km/s (3KCMB) t = days t = days - Next slide is NGC ~~~~~~~~~ - And these are observed light curves. ~~~~~~~~~~~~~~~~~~~~~~~ - We measured the lag time to be ten or twenty days. t = days DSS Bj-band image

9 NGC 3227 DSS Bj-band image Vnuc=14.4mag 1480 km/s (3KCMB)
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. NGC 3227 Vnuc=14.4mag 1480 km/s (3KCMB) t = days - Next is NGC ~~~~~~~~~ - And these are observed light curves. ~~~~~~~~~~~ - We measured the lag time to be about twenty days. DSS Bj-band image

10 NGC 7469 DSS R-band image Vnuc=14.5mag 4521 km/s (3KCMB)
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. NGC 7469 Vnuc=14.5mag 4521 km/s (3KCMB) t = days - The final is NGC ~~~~~~~~~ - And these are observed light curves. ~~~~~~~~~~~ - We measured the lag times to be seventy or ninety days. t = days DSS R-band image

11 Lag time vs. Optical Luminosity
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Lag time vs. Optical Luminosity Before MAGNUM After this work N 7469 N 5548 N 4151 N 3227 N 4051 GQ Comae (Sitko et al.+93) F 9 (Clavel et al. +89) N 3783 (Glass +92) N 4151 (Oknyanskij et al. +99) Mrk 744 (Nelson +96) - From here, I will discuss about what our results mean. ~~~~~~~~~~~~~~~~~~~ - I will plot our lag time measurements on luminosity vs. lag time diagram. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - These are lag time measurements reported before our observation. - Before our observation, there have been a few measurements. - Now, I plot our results here. - There is a tight correlation between lag time and luminosity for a wide luminosity range of Seyfert 1 galaxies. ~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Minezaki et al. (2004) and references therein (nucleus)

12 Lag time vs. Optical Luminosity with BLR lags
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Lag time vs. Optical Luminosity with BLR lags NIR(K-band) Broad Emission Line F9: Clavel et al. (+89) Rodriguez-Pascual et al. (+97) Peterson et al. (04) N3783: Reichert et al. (+94) N7469: Wanders et al. (+97) Kriss et al. (00) Collier et al. (+98) N5548: Peterson et al. (02) Krolik et al. (1991) Peterson & Wandel. (+99) Dietrich et al. (+93) Korista et al. (+95) N4151: Clavel et al. (+90) Maoz et al. (+91) Kaspi et al. (+96) - The next point we should examine is how large the infrared lags are compared with broad-emission line lags. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - This is the same diagram with the last slide. - Here, these are lag times for broad emission lines reported for the objects - And I again plot the infrared lags on this diagram. - As you can see, the infrared lags are located on near upper border of broad-emission line lags! Broad-emission line lags for objects that also have infrared lags Including Hi & Lo ionization lines) (nucleus) N3227: Winge et al. (+95) Onken et al. (03) Shemmer et al. (04)

13 Supported Picture of Central sub-parsec of Seyfert 1 Galaxies
The Central Engine of Active Galactic Nuclei Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Supported Picture of Central sub-parsec of Seyfert 1 Galaxies BLR : Within inner border of dust torus Dust torus : Inner size of the dust torus Rin L0.5 pc - Next, let me describe last two discussions on this schematic viewgraph. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - Irradiated by the central engine, the inner radius of the dust torus of AGN is determined as being proportional to square-root of its central luminosity. - And, broad-emission line region is within inner border of dust torus

14 The Central Engine of Active Galactic Nuclei
Xi’an, Oct , 2006 Reverberation Radius of Inner Dust Torus Suganuma et al. Summary Lag time measurements between flux variation of V-band and K-band for nearby Seyfert 1 galaxies with MAGNUM telescope cleared that … There is tight correlation between optical luminosity and near-infrared lag with t L0.5opt . Near-infrared lags are located on near the upper border of broad-emission line lags on L- t plane. In other words, it could be say that … Inner radius of the dust torus is determined as being proportional to square root of its central luminosity. Inner border of the dust torus is located near outer border of broad-emission line region (BLR). - So, to summarize, our dust reverberation observations for nearby type 1 AGNs using MAGNUM telescope cleared these two things. ~~~~~~~~~~~~~ - First, there is a tight correlation between optical luminosity and near-infrared lag, with delta t proportional to square root of optical luminosity. - Second, these lags are located on near the ceiling of those of broad-emission lines. - In other words, we can say these things. - Please see our recent publication here for details. - Thank you very much. ~~~~~~~~~~~~~~~~ ( Suganuma et al. 2006, ApJ 639, 46 )

15 １１／１１：約１４分。聴衆側を見て話そう。 １１／１２：約１５分。スライド見なくても説明出来るように。最後のsummaryの短縮テクニックも練習。 １１／１３：原稿そのまま読むと約１０分⇒もう１分分程度短くした方が良いが、、、ちょっとしんどいか。。 １５分 　　　　　　１３分３０秒

16 時間遅延 (UV/可視連続波 → 近赤外連続波)
ダスト領域の反響マッピング ダストの熱平衡 ： LUV／4πr2 ＝ 4＜Qλ＞σT4 ダスト温度に上限（昇華温度～1500K） ⇒ ダスト分布に内縁 時間遅延 (UV/可視連続波 → 近赤外連続波) 　～ダストトーラス内縁半径÷ｃ

17 過去のダスト反響観測 時間遅延(UV/可視→２μm)の報告は数例 粗いサンプリング（間隔～＜１ヶ月） 文献データの寄せ集め
Mrk 744 (Nelson 1996) K光度曲線 V光度曲線 粗いサンプリング（間隔～＜１ヶ月） 文献データの寄せ集め NGC 4151 (Oknyanskij et al. 1999) K光度曲線 V光度曲線 ⇒ 専用望遠鏡によるインテンシブかつ 長期観測が必要

18 無人自動観測の実現 自動観測条件判断 自動観測スケジューリング 赤外線雲モニター 遠隔監視システム 菅沼修士論文
この形式の雲モニター（すばる、　岡山等）のオリジナル Suganuma et al. in preparation

19 赤外線（10μm）全天雲モニター くもり 快晴 うす雲

20 The optical and NIR monitoring observation since Jan. 2001
83 target objects of Seyfert 1 galaxies and radio-quiet quasars 2DF , 2DF , 2DF , 2DF , 2DF , 2DF , 2DF , 2QZ , 3C120, Akn120, EDR , EDR , IRAS , IRASF , KUV , L , LBQS , LBQS , LBQS , LBQS , MOA2001BLG5, MOA201BLG5, MS , MS , Mrk110, Mrk335, Mrk509, Mrk590, Mrk744, Mrk79, Mrk817, NGC2403_ulx, NGC3031, NGC3227, NGC4051, NGC4151, NGC4395, NGC4395d1, NGC4395d2, NGC4395d3, NGC4395d4, NGC4639, NGC5548, NGC7469, PG0844p349, PG , PG1613p658, PHL1070, Q , RXJ17591p6635, RXJ17595p6645, RXJ17597p6629, RXJ , RXJ18003p6615, RXJ18006p6641, RXJ18009p6622, RXJ , RXJ , RXJ18012p6631, RXJ18015p6632, RXJ , RXJ , RXSJ , RXSJ , S , S0257m0027, SDSS , SDSS , SDSS , SDSS , SDSS , SDSSJ , SDSSJ , SDSSJ , SDSSJ , SDSSJ , SDSSJ1004p4112, SDSSJ , SDSSJ , SDSSpJ1204m0021, TON730, mcg 2005 2006 Observation continues until present. 観測ログ貼り付け

21 データ整約、測光 イメージリダクション 参照星は非変光星 アパーチャー測光 相対測光光度曲線 測光エラー：σ＜～0.01mag
参照星A-参照星B AGN-参照星

22 データ整約、測光 フラックス較正(←標準星) シーイング補正 銀河フラックス見積もり (2次元プロファイルフィット)
　フラックス較正(←標準星) 　シーイング補正 銀河フラックス 　銀河フラックス見積もり (2次元プロファイルフィット) 　 誤差1-2割 (オフセットはCCF解析に影響しない) 銀河フラックス AGN

23 光度曲線 可視 (U)BV： 細かな変動の存在。バンド間で同期。 赤外 HK： 可視よりも滑らか。可視に対して時間遅延。 NGC 5548

24 光度曲線 可視 (U)BV： 細かな変動の存在。バンド間で同期。 赤外 HK： 可視よりも滑らか。可視に対して時間遅延。 NGC 4051

25 光度曲線 可視 (U)BV： 細かな変動の存在。バンド間で同期。 赤外 HK： 可視よりも滑らか。可視に対して時間遅延。 NGC 3227

26 光度曲線 可視 (U)BV： 細かな変動の存在。バンド間で同期。 赤外 HK： 可視よりも滑らか。可視に対して時間遅延。 NGC 7469

27 観測天体の可視-近赤外SED 可視：フラット 近赤外：スティープ 1μm付近に凹み

28 flux vs. flux diagram in the optical
V フラックス vs. B フラックス バンド間で同期 フラックス変動量の比がバンド間で一定 変動量比から見積もる中心核カラー　　 B-V～

29 flux vs. flux diagram in the near-infrared
K フラックス　vs. H フラックス 可視に比べて変動が滑らか 変動量比から見積もる中心核カラー 　　H-K～ 　　→　Black body 　　　　　 K

30 時間遅延の誤差評価 光度曲線（V,K）のモンテカルロシミュレーション ⇒ 多数のCCF(τ) いかに誤差原因を 反映させるか？
⇒ τpeak の ヒストグラム

31 誤差の２大原因 ⇒ 観測点間の変動を直接シミュレートする 手法を新しく導入。
観測フラックス誤差の伝播　(影響小)　　 ⇒ フラックスランダマイズ法 変動のアンダーサンプリング (影響大) ⇒ 評価難しく過去に適当な手法が無い これまでの手法： 観測とは異なるモデル依存の光度曲線　　　 　　（Maoz & Netzer 1989; White & Peterson 1994） 観測データの間引き 　（Peterson et al. 1998） ⇒ 観測点間の変動を直接シミュレートする　　手法を新しく導入。

32 観測点間の変動シミュレーション 光度曲線の Structure Function （SF） ⇒ 観測点間の変動不定量

33 Structure Function (SF)
SF: 変動量と時間スケールの関係（→ Power Spectrum） SFの再現 ⇒ 変動性質の再現 シミュレーション光度曲線のSF 観測光度曲線のSF +

34 活動銀河核の時間変動 活動銀河核の一般的性質 数日～数年スケールの変動の確率過程的重ね合わせ NGC ５５４８ 中心核 15年間の可視変動
AGN Watch λ5100Å （Peterson et al. 2002） MAGNUM 　Vバンド NGC ５５４８ 中心核 15年間の可視変動