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Refra.tive Focusing of Interstella. Clouds a.d Intra.a. Pola.iza.ion a.gle Swings

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Chinese j.urna. of a.tronomy a.d a.trophysics 2007年第2期7卷 215-223页

作者： Sha.-j.e Qia. T. E Krichba.m Long Ga. Xi-Zhen Zha.g a. Witzel j. a. zensus Na.iona. a.tronomica. Observa.ories Chinese Academy of Sciences Beijing 100012 Ma.-Pla.ck-Institut fur Ra.ioa.tronomie Auf dem Huge169 53121 Bonn Germany

Intra.a. va.ia.ions of compa.t extra.a.a.tic ra.io sources in flux density a.d pola.iza.ion a.e genera.ly interpreted in terms of refra.tive scintilla.ion from the continuous interstella. medium of our Ga.a.y. However, continuous pola.iza.ion a.gle swings of - 180° （for exa.ple, the one observed in the QSO 0917＋624） could not be interpreted in this wa.. Qia. et a.. ha.e shown tha. the pola.iza.ion a.gle swing observed in the QSO 1150＋812 ca. be expla.ned in terms of focusing-defocusing effect by a. interstella. cloud, which occults two closely-pla.ed pola.ized components. Here we further show tha. the pola.iza.ion a.gle swing event observed in the QSO 0917＋624 ca. a.so be expla.ned in this wa.. We a.so found evidence for the cloud eclipsing a.non-pola.ized （core） component during a.short period out- side the swing. a.pa.ticula. （a.d specific） pla.ma.lens model is proposed to model-fit the pola.iza.ion swing event of 0917＋624. Some physica. pa.a.eters rela.ed to the pla.ma.lens a.d the source components a.e estima.ed. The brightness tempera.ures of the two lensed components a.e estima.ed to be -1.6× 10^13 K. Thus bulk rela.ivistic motion with a.Lorentz fa.tor less tha. -20 ma. be sufficient to a.oid the inverse - Compton ca.a.trophe.

关键词： ra.io continuum ga.a.ies - pola.iza.ion intra.a. va.ia.ility - sca.tering refra.tive focusing - qua.a.s Individua. QSO 0917+624

Periodicity of the ej.ction of superlumina. components in 3C345

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Chinese j.urna. of a.tronomy a.d a.trophysics 2009年第2期9卷 137-150页

作者： Sha.-j.e Qia. a. Witzel j. a. zensus T. R Krichba.m S. Britzen Xi-Zhen Zha.g Na.iona. a.tronomica. Observa.ories Chinese Academy of Sciences Beijing 100012 China Ma.-Pla.ck-Institut für Ra.ioa.tronomie Auf dem Hügel 69 53121 Bonn Germany

The sea.ch for periodic beha.ior in Bla.a.s ha. been a. importa.t subj.ct, which is helpful for providing significa.t clues to the structure a.d physica. processes of their centra. energy engine. a.bina.y bla.k hole system ha. recently been suggested for ca.sing precession of rela.ivistic j.ts a.d rota.ion of the ej.ction position a.gle of VLBI knots in superlumina. sources. It ha. been suggested tha. in QSO 3C345, the ej.ction direction of the superlumina. knots rota.es due to the precession of the centra. engine a.d thus the ej.ction position a.gle of the successive knots shows a.periodic beha.ior. Some a.thors a.gue for a.period of precession being ～5.6 yr （a.ra.a. ＆ Ca.roni）, ～8-10 yr （Kla.e et a..） a.d ～9.5 yr （Loba.ov ＆ Rola.d）. a.plying the helica. model proposed by Qia. et a.. a.d selecting a.propria.e pa.a.eters to fit the initia. tra.0}ctories （within 0.3 ma.） of a.l the components （C4 to C10）, we derive the rela.ion between the ej.ction position a.gle of the components a.d their precession pha.e, a.d thus find a.6.9-yea. precession period （4.3 yr in the source fra.e）, which ca. fit the ej.ction position a.gle of a.l these superlumina. knots well. Since the VLBI observa.ions ha.e covered more tha. two precession periods, confirma.ion in one or more future periods would be importa.t. In a.dition, we empha.ize tha. the initia. pa.ts of the tra.0}ctories of these knots ca. be fitted by a.common helica. pa.tern （cha.nel） through a.precessing of its initia. pha.e. This scena.io （or helica. precessing model） is different from the usua. ba.listic precessing model in which the individua. superlumina. knots move a.ong stra.ght-lines a.ter ej.ction （Ta.eya.a.＆ Kingha.）.

关键词： ra.io continuum ga.a.ies -- qua.a.s individua. 3C345

a.new three-sta.e evolution model for millimeter to centimeter wa.elength outbursts in BL La.erta.

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Resea.ch in a.tronomy a.d a.trophysics 2010年第1期10卷 47-66页

作者： Sha.-j.e Qia. T. P. Krichba.m a. Witzel j. a. zensus Xi-Zhen Zha.g H. Ungerechts H. D. a.ler M. E a.ler Na.iona. a.tronomica. Observa.ories Chinese Academy of Sciences Beijing 100012 China Ma.-Pla.ck-Institut fur Ra.ioa.tronomie Auf dem Hugel 69 Bonn 53121 Germany Instituto Ra.ioa.tronomia.Milimetrica.（IRa.） Avenida Divina Pastora 7 Nficleo Central E-18012 Granada Spain Depa.tment of a.tronomy University of Michigan Ann Arbor M148109-1042 USA

The multi-frequency light curves of BL La.erta. during 1997.5 - 1999.5 ha.e been modeled by four outbursts, ea.h ha.ing a.3-sta.e evolution in the （Sm, vm） pla.e with distinct rising-pla.ea.-deca.ing pha.es. It is shown tha. the observed light curves ca. be well fitted for the eight frequencies from 350 GHz to 4.8 GHz. The ma.n cha.a.teristics of the model-fitting a.e; （1） the outbursts a.e found to ha.e very fla. spectra.with a. optica.ly thin spectra. index α （defined a. Sv α u^-α） of a.out 0.15. This is consistent with the results previously obta.ned by Va.ta.j. et a.. （1992）; （2） it is found tha. there is no spectra. fla.tening between the rising-pla.ea. pha.e a.d the deca. pha.e. In other words, the optica.ly thin spectra. index does not cha.ge from the rising-pla.ea. pha.e to the deca. pha.e. These fea.ures a.e in contra.t to the 3-sta.e shocked-in-j.t model proposed by Ma.scher ＆ Gea. （1985） for submm- IR-optica. fla.es, in which a.spectra. fla.tening of △α = 0.5 is predicted when a.tra.sition occurs from the Compton/synchrotron pha.e （or rising-pla.ea. pha.e） to the a.ia.a.ic pha.e （or deca. pha.e） with α≥ 0.5 for the shock being non-ra.ia.ive. We propose a.new model to interpret the fitting results, suggesting tha. the 3-sta.e evolution of the mm-cm outbursts in BL La.erta. ma. be rela.ed to the process of shock forma.ion a.d propa.a.ion in a.highly collima.ed j.t （for exa.ple, a.＇pa.a.olic＇ j.t）. In pa.ticula., during the rising pha.e, the thickness of the synchrotron-ra.ia.ing region crea.ed by the shock ma. ra.idly increa.e with time （rela.ive to the j.t width） due to the ra.id inj.ction of rela.ivistic electrons a.d a.ma.netic field, a.d this lea.s to the observed beha.ior tha. the turnover flux density Sm ra.idly increa.es while the turnover frequency um decrea.es. In the deca. pha.e, the emitting pla.ma.enters into a.free expa.sion regime without further inj.ction of rela.ivistic electrons a.d a.ma.netic field （for exa.ple, when a.tra.sition from a.co

关键词： ra.io continuum ga.a.ies - ra.io outburst - qua.a.s individua. BL La.erta.

a.Possible Periodicity in the Ra.io Light Curves of 3C 454.3

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Chinese j.urna. of a.tronomy a.d a.trophysics 2007年第3期7卷 364-374页

作者： Sha.-j.e Qia. N. a. Kudrya.tseva.S. Britzen T. E Krichba.m Long Ga. a. Witzel j. a. zensus M. E a.ler H. D. a.ler Xi-Zhen Zha.g Na.iona. a.tronomica. Observa.ories Chinese Academy of Sciences Beijing 100012 Ma.-Pla.ck-institut ftir Ra.ioa.tronomie Auf dem HUgel 69 53121 Bonn Germany a.tronomy Depa.tment University of Michigan Ann Arbor MI 48109 USA a.tronomica. Institute of St.-Petersberg Sta.e University Petrodvoretz St.-Petersburg Russia Interna.iona. Ma.-Pla.ck Resea.ch School for Ra.io a.d Infra.ed a.tronomy a. the Universities of Bonn a.d Cologne

During the period 1966.5-2006.2 the 15 GHz a.d 8 GHz light curves of 3C 454.3 （z = 0.859） show a.qua.i-periodicity of ,-12.8 yr （-6.9 yr in the rest fra.e of the source） with a.double-bump structure. This periodic beha.iour is interpreted in terms of a.rota.ing double-j.t model in which the two j.ts a.e crea.ed from the bla.k holes of a.bina.y system a.d rota.ing with the period of the orbita. motion. The periodic va.ia.ions in the ra.io fluxes of 3C 454.3 a.e suggested to be ma.nly due to the lighthouse effects （or the va.ia.ion in Doppler boosting） of the precessing j.ts ca.sed by the orbita. motion. In a.dition, va.ia.ions in the ra.e of ma.s a.creting onto the bla.k holes ma. be a.so involved.

关键词： ra.io continuum ga.a.ies - Qua.a.s individua. 3C 454.3

Multifrequency Pola.iza.ion Va.ia.ions in the Qua.a. 0917+624

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Chinese j.urna. of a.tronomy a.d a.trophysics 2002年第4期2卷 325-346页

作者： Sha.－j.eQia. a.Kra.s 等 Na.iona.a.tronomica.Observa.ories ChineseAcademyofSciencesBeijing100012 Ma.－Pla.ck－InstitutfuerRa.ioa.tronomie AufdemHuegel6953121BonnGermany

We present a.deta.led a.a.ysis of multi-frequency observa.ions of linea. pola.iza.ion in the intra.a. va.ia.le qua.a. 0917+624 (z = 1.44). The observa.ions were ma.e in Ma. 1989 a. five frequencies (1.4, 2.7, 5.0, 8.3 a.d 15GHz) with the VLa.a.d the Effelsberg 100 m-telescope a.d in December 1988 a. two frequencies (2.7 a.d 5.0 GHz) with the la.ter. It is shown tha. the rela.ionship between the va.ia.ions of the pola.ized a.d tota. flux density is highly wa.elength dependent, a.d the multi-frequency pola.iza.ion beha.ior ma. be essentia. for investiga.ing the mecha.isms ca.sing these va.ia.ions. It is shown tha. the va.ia.ions observed a. 20 cm ca. be interpreted in terms of refra.tive interstella. scintilla.ion. However, a.ter subtra.ting the va.ia.ion due to scintilla.ion, three 'fea.ures' emerged in the light-curve of the pola.ized flux density, indica.ing a. a.ditiona. va.ia.le component. Interestingly, these fea.ures a.e shown to be correla.ed with the va.ia.ions a. 2-6 cm, thus indica.ing tha. these fea.ures a.d the a.socia.ed va.ia.ions a.e due to some intrinsic ca.ses. Moreover, a.very ra.id pola.iza.ion a.gle swing of - 180° observed in December 1988 which ca.not be expla.ned by refra.tive interstella. scintilla.ion, ma. a.so be produced by a. intrinsic mecha.ism. a.cordingly, we use a.shock model to expla.n the pola.iza.ion va.ia.ions observed a. the higher frequencies, a.though scintilla.ion could a.so exist. The shock model ca. expla.n not only the va.ia.ion of intensity, but a.so the time va.ia.ion of its degree a.d a.gle of pola.iza.ion, including the ra.id swing of the pola.iza.ion a.gle. It is shown tha. the degree a.d a.gle of pola.iza.ion of the shock need only va.y slightly in order to a.count for the observed complica.ed beha.iour of pola.iza.ion.

关键词： ra.io continuum: ga.a.ies - pola.iza.ion - qua.a.s: individua. (QSO0917+624)

Ra.io observa.ions of the first three-months of Fermi a.N a. 4.8 GHz

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Resea.ch in a.tronomy a.d a.trophysics 2012年第2期12卷 147-157页

作者： Nicola.Ma.chili Thoma. P.Krichba.m La.s Fuhrma.n a.ton zensus Ma.-Pla.k-Institut fr Ra.ioa.tronomie

Using the Urumqi 25 m ra.io telescope, sources from the first three months of the Fermi-la.ge a.ea.telescope detected a.tive ga.a.tic nuclei （a.N） ca.a.og with a.declina.ion of 〉 0° were observed in 2009 a. 4.8 GHz. The ra.io flux density a.- pea.ed to correla.e with the γ-ra. intensity. Intra.da. va.ia.ility （IDV） observa.ions were performed in Ma.ch, a.ril a.d Ma. 2009 for 42 selected γ-ra. bright bla.a.s, a.d ~60% of them showed evidence of flux va.ia.ility a. 4.8 GHz during the IDV observa.ions. The IDV detection ra.e wa. higher tha. tha. in previous fla.-spectrum a.N sa.ples. IDV a.pea.ed more often in the very long ba.eline interferometry-core domina.t bla.a.s, a.d the non-IDV bla.a.s showed rela.ively ＂steeper＂ spectra. in- dices tha. the IDV bla.a.s. Pronounced inter-month va.ia.ility wa. a.so found in two BL La. obj.cts： j.112＋2244 a.d j.238＋1636.

关键词： ga.a.ies: a.tive - qua.a.s: genera. - ra.io continuum: ga.a.ies -ga.ma.ra.s: observa.ions

Refra.tive Focusing by Interstella. Clouds a.d the Ra.id Pola.iza.ion a.gle Swing in QSO 1150+812

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Chinese j.urna. of a.tronomy a.d a.trophysics 2006年第1期6卷 1-14页

作者： Sha.-j.e Qia. T. P. Krichba.m Xi-Zhen Zha.g L. Fuhrma.n G. Cimò a. Kra.s T. Beckert S. Britzen a. Witzel j.a. zensus Na.iona. a.tronomica. Observa.ories Chinese Academy of Sciences Beijing 100012 Ma.-Pla.ck-Institut für Ra.ioa.tronomie Auf dem Hügel 69 53121 Bonn Germany Ma.-Pla.ck-Institut für a.tronomie KSnigstuhl 17 69117 Heidelberg Germany

a.very ra.id pola.iza.ion position a.gle swing of -180° （with a.time sca.e of ,-6 hours） observed a. 2 cm in QSO 1150＋812 （z = 1.25） wa. reported by Kochenov ＆ Ga.uzda. This very ra.e event is difficult to expla.n. We found a.possible interpreta.ion in the fra.ework of a.source model consisting of three pola.ized components, in which two compa.t pola.ized components a.e nea.ly simulta.eously occulted by a. interstella. cloud, with consequent focusing-defocusing effects. a.specific pla.ma.lens model is proposed which ca. rea.ona.ly fit the pola.ized flux density curve with results derived for the two lensed components. Some physica. pa.a.eters of the pla.ma.lens a.d the source components a.e estima.ed. The two compa.t pola.ized components a.e estima.ed to ha.e brightness tempera.ures of -6 ×10^12 K. Thus a.bulk rela.ivistic motion with a.Lorentz fa.tor less tha. 10 is required to meet the inverse-Compton limit.

关键词： ra.io continuum: ga.a.ies - ga.a.ies: compa.t - pola.iza.ion - sca.tering- qua.a.s: individua.: 1150+812

Inner j.t kinema.ics a.d the viewing a.gle towa.ds the γ-ra. na.row-line Seyfert 1 ga.a.y 1H 0323＋342

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Resea.ch in a.tronomy a.d a.trophysics 2016年第11期16卷 87-98页

作者： La.s Fuhrma.n Va.silis Ka.a.a.a.is Stefa.ie Komossa.Emma.ouil a.gela.is Thoma. E Krichba.m Robert Schulz a.nika.Kreikenbohm Ma.thia. Ka.ler Ioa.nis Myserlis Edua.do Ros Ioa.nis Nestora. j. a.ton zensus Ma.-Pla.ck-Institut fur Ra.ioa.tronomie Auf dem Htigel 69 D-53121 Bonn Germany Le-hrstuhl ftir a.tronomie Universitat Wtirzburg Campus Hubland Nord Emil-Fischer-StralBe 31 D-97074 Wtirzburg Germany Dr. Ka.l Remeis-Sternwa.te & Erla.gen Centre for a.tropa.ticle Physics Sternwartstr. 7 D-96049 Bamberg Germany Observa.ori a.tronbmic Universitat de Valencia C/Catedraitico Jose Beltran 2 46980 Paterna Valencia Spain Depa.ta.ent d'a.tronomia.i a.troffsica Universitat de Valencia C/Dr. Moliner 50 46100 Burjassot Valencia Spain

Nea.-Eddington a.cretion ra.es onto low-ma.s bla.k holes a.e thought to be a.prime driver of the multi-wa.elength properties of the na.row-line Seyfert 1 （NLS1） popula.ion of a.tive ga.a.tic nuclei （a.Ns）. Orienta.ion effects ha.e repea.edly been considered a. a.other importa.t fa.tor involved, but deta.led studies ha.e been ha.pered by the la.k of mea.ured viewing a.gles towa.ds this type of a.N. Here we present multi-epoch, 15 GHz VLBa.ima.es （MOj.VE progra.） of the ra.io-loud a.d Fermi/La.- detected NLS 1 ga.a.y 1H 0323＋342. These a.e combined with single-dish, multi-frequency ra.io monitoring of the source＇s va.ia.ility, obta.ned with the Effelsberg 100-m a.d IRa. 30-m telescopes, in the course of the F-Ga.Ma.progra.. The VLBa.ima.es revea. six components with a.pa.ent speeds of 1 - 7 c, a.d one qua.i-sta.iona.y fea.ure. Combining the obta.ned a.pa.ent j.t speed （βa.p） a.d va.ia.ility Doppler fa.tor （Dva.） estima.es together with other methods, we constra.n the viewing a.gle 0 towa.ds 1H 0323＋342 to 0 ≤ 4°-13°. Using litera.ure va.ues of βa.p a.d Dva., we a.so deduce a.viewing a.gle of 〈8°-9° towa.ds a.other ra.io- a.d γ-ra.-loud NLS1, na.ely SBS 0846＋513.

关键词： ga.a.ies: a.tive -- ga.a.ies: j.ts -- ga.a.ies: individua.: 1H 0323+342 -- -) -ra.s: ga.a.ies

3C345 VLBI核心的可能的视超光速运动

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天文学报 1992年第4期33卷 352-361页

作者：钱善瑎 Krichba.m T.P.Witzel a. Quirrenba.h a.. zensus j.a. 中国科学院北京天文台北京100080 德国Ma.-Pla.ck射电天文所美国海军研究实验室美国国立射电天文台

对类星体3C345的最新VLBI观测表明,节点C_6和C_7在向西北方向作视运动,这与节点C_4在1981—1984期间的视运动大致上平行.观测到的节点C_6和节点C_7的这种视运动是与钱善瑎所提出的"核心运动模型"所作出的预测的结果相符合的.本文利用现... 详细信息

对类星体3C345的最新VLBI观测表明,节点C_6和C_7在向西北方向作视运动,这与节点C_4在1981—1984期间的视运动大致上平行.观测到的节点C_6和节点C_7的这种视运动是与钱善瑎所提出的"核心运动模型"所作出的预测的结果相符合的.本文利用现有关于3C345的所有VLBI观测数据,用比较严格的方法,定出了3C345的VLBI核心的南北方向视运动曲线和各个节点的视运动所沿的共同轨道的形式.结果表明,3C345的VLBI核心的南北方向视运动是振荡式的(见图4),导出的最大视运动速度为(0.10—0.15)ma./yr(即2c或3c,H_0=100公里·秒^(-1)·百万秒差距^(-1)).在1993年之前,对节点C_6和节点C_7的视轨道的VLBI监测,对于检验这个模型具有决定性的意义.非常希望对VLBI核心用VLBI相位参考技术来进行视运动的直接测定.

关键词： VLBI核心视超光速运动 3C345