陳永云, 張雄, 熊定榮
(云南師范大學(xué) 物理與電子信息學(xué)院,云南 昆明650500)
射電類星體間的射電輻射存在巨大的差異,根據(jù)這一差異可將射電類星體分為射電噪類星體(RLQs)和射電寧?kù)o類星體(RQQs)[1-2].一般使用射電噪度R來(lái)區(qū)分RQQs和RLQs,通常使用5GHz的光度與B波段的光度之比來(lái)計(jì)算射電噪度,即R=Lν(6cm)/Lν(B),取 R=10為 RQQs和RLQs的分界線,R>10為RLQs,R<10為RQQs.另外一種分類的標(biāo)準(zhǔn)是依據(jù)射電光度L6cm,取L6cm≈1024W·Hz-1·Sr-1為RQQs和RLQs的分界線,射電光度大于1024W·Hz-1·Sr-1是RLQs,反之是 RQQs[3-6].Strittmatter等人[7]發(fā) 現(xiàn) 電 噪度R分布呈雙峰狀,Kellermann等人[8]證實(shí)了這一結(jié)論,Miller等人[9]等人對(duì)光學(xué)選類星體樣本研究發(fā)現(xiàn),大多數(shù)光學(xué)選類星體是RQQs,僅僅只有10%~20%的光學(xué)選類星體是RLQs.最近,一些人研究射電選類星體發(fā)現(xiàn)射電噪度R分布在一個(gè)很寬的范圍,其分布呈雙峰狀的結(jié)論受到質(zhì)疑[10-14].大多數(shù)的研究發(fā)現(xiàn) RLQs的射電輻射是由噴流形成的,而RQQs的射電輻射是由吸積盤(pán)形成的,其內(nèi)稟因素仍然不清楚[15-16].對(duì)于 RLQs和RQQs,許多人研究了黑洞質(zhì)量與射電噪度R或射電光度之間的關(guān)系,一部分研究結(jié)果顯示它們之間有關(guān)系,而另外的一些研究結(jié)果卻顯示它們之間沒(méi)有關(guān)系[17-25].黑洞質(zhì)量通常被作為研究RLQs和RQQs的重要參量,大多數(shù)研究發(fā)現(xiàn)射電輻射產(chǎn)生的相對(duì)論電子形成了噴流,用黑洞質(zhì)量來(lái)了解噴流的起源和射電類星體的性質(zhì)具有重要的意義[26-34].最近 Marconi[35]等人指出輻射壓對(duì)寬線氣體云的運(yùn)動(dòng)有重要影響,在進(jìn)行黑洞質(zhì)量估算時(shí)應(yīng)考慮輻射壓的影響[36].根據(jù)這些研究背景,我們計(jì)算了RQQs和RLQs考慮輻射壓的影響時(shí)的黑洞質(zhì)量.應(yīng)用一元線性回歸方法對(duì)黑洞質(zhì)量、射電光學(xué)強(qiáng)度比、熱光度、紅移、5GHz射電光度之間的相關(guān)性進(jìn)行分析,并研究了考慮輻射壓的愛(ài)丁頓吸積、Hβ發(fā)射線寬度、黑洞質(zhì)量等的分布,得到一些結(jié)果和結(jié)論.
Miller和Vestergaard研究發(fā)現(xiàn)寬線區(qū)半徑RBLR和5 100?光度有關(guān)系[9,32,37-40],即RBLR:
Laor[17]用Hβ的發(fā)射線寬度計(jì)算黑洞質(zhì)量,根據(jù)以下公式來(lái)計(jì)算黑洞質(zhì)量:
在(1)和(2)式中It-days為光天,G為引力常數(shù),F(xiàn)WHM為 Hβ發(fā)射線寬度,尺度因子f=3[29-32].當(dāng)考慮輻射壓時(shí),黑洞質(zhì)量估算公式為[36]
圖1和圖2分別是RQQs未考慮輻射壓和考慮輻射壓計(jì)算的黑洞質(zhì)量與熱光度的關(guān)系圖.圖3和圖4分別是RLQs未考慮輻射壓和考慮輻射壓計(jì)算的黑洞質(zhì)量與熱光度的關(guān)系圖.利用ORIGIN分析了它們的黑洞質(zhì)量和熱光度之間的關(guān)系,得到如下結(jié)論:考慮輻射壓的RLQs和RQQs的黑洞質(zhì)量與熱光度的相關(guān)性比沒(méi)有考慮輻射壓的黑洞質(zhì)量與熱光度的相關(guān)性好;RLQs的黑洞質(zhì)量與熱光度的相關(guān)性比RQQs的強(qiáng)(見(jiàn)表1).
圖1 射電寧?kù)o類星體未考慮輻射壓黑洞質(zhì)量對(duì)熱光度的關(guān)系圖Fig.1 The correlation between black hole masses of RQQs without radiation pressure considered and bolometric luminosity
圖2 射電寧?kù)o類星體考慮輻射壓黑洞質(zhì)量 對(duì)熱光度的關(guān)系圖 Fig.2 The correlation between black hole masses of RQQs with radiation pressure considered and bolometric luminosity
圖3 射電噪類星體未考慮輻射壓黑洞質(zhì)量 對(duì)熱光度的關(guān)系圖 Fig.3 The correlation between black hole masses of RLQs without radiation pressure considered and bolometric luminosity
圖4 RLQs考慮輻射壓黑洞質(zhì)量 對(duì)熱光度的關(guān)系圖Fig.4 The correlation between black hole masses of RLQs with radiation pressure considered and bolometric luminosity
利用同樣的方法,分析了黑洞質(zhì)量與射電噪度之間的相關(guān)性,得到:考慮輻射壓后,RQQs和RLQs的黑洞質(zhì)量與射電噪度的相關(guān)性比沒(méi)有考慮輻射壓黑洞質(zhì)量與射電噪度的相關(guān)性好.考慮輻射壓后,RLQs的黑洞質(zhì)量與R的相關(guān)性比RQQs的強(qiáng)(見(jiàn)表1).
取宇宙學(xué)參量 H0=70km·s-1·Mpc-1,Ωm=0.27,ΩΛ=0.73[41].我們采用射電譜指數(shù)αR=0.5,利用5GHz流量密度計(jì)算它們的射電光度[42],并分析了黑洞質(zhì)量與射電光度之間的相關(guān)性,得到如下結(jié)果:考慮輻射壓的RQQs和RLQs的黑洞質(zhì)量與射電光度的相關(guān)性比沒(méi)有考慮輻射壓黑洞質(zhì)量與射電光度的相關(guān)性好;考慮輻射壓后,RLQs的黑洞質(zhì)量與射電光度的相關(guān)性比RQQs的強(qiáng)(見(jiàn)表1).
分析黑洞質(zhì)量與紅移之間的相關(guān)性,得到:考慮輻射壓后,RQQs黑洞質(zhì)量和紅移的相關(guān)性比RLQs的強(qiáng)(見(jiàn)表1).
表1 利用ORIGIN分析結(jié)果Table 1 The result obtained by using ORGIN
圖5是考慮輻射壓黑洞質(zhì)量與沒(méi)考慮輻射壓黑洞質(zhì)量的比值取對(duì)數(shù)后和發(fā)射線寬度的關(guān)系圖,圖6和圖7分別是RQQs和RLQs考慮輻射壓黑洞質(zhì)量與發(fā)射線寬度的關(guān)系圖.我們可以看出在lg(Mma/M)=0的實(shí)線附近RQQs偏離很大(如圖5),這說(shuō)明輻射壓對(duì)RQQs黑洞質(zhì)量有很大的影響,而對(duì)RLQs黑洞質(zhì)量影響很小,表明大部分RQQs發(fā)射線比RLQs的發(fā)射線窄,其柱密度比RLQs的低.圖6可以看出RQQs的發(fā)射線寬度范圍為1 500~8 600km·s-1,而RLQs的發(fā)射線寬度范圍為1 000~14 000km·s-1.[30-31],我們利用相關(guān)的數(shù)據(jù)計(jì)算了考慮輻射壓后的吸積率.圖8是考慮輻射壓后的愛(ài)丁頓比與射電噪度的分布,圖9和圖10分別是RQQs和RLQs未考慮輻射壓與考慮輻射壓愛(ài)丁頓比的分布.從圖8可以看出,用考慮輻射壓后的愛(ài)丁頓比與射電噪度的關(guān)系圖可以區(qū)分射電寧?kù)o和RLQs,且RQQs和RLQs的愛(ài)丁頓比沒(méi)有超愛(ài)
圖5 考慮輻射壓的黑洞質(zhì)量隨發(fā)射線寬度的分布Fig.5 The distribution of black hole masses of RQQs and RLQs with radiation pressure considered on FWHM
圖6 RQQs的輻射壓黑洞質(zhì)量對(duì)發(fā)射線寬度的關(guān)系圖 Fig.6 The correlation between black hole masses of RQQs with radiation pressure considered and FWHM
射電類星體的輻射效率與吸積率有關(guān),吸積率(愛(ài)丁頓比)等于熱光度和愛(ài)丁頓光度的比值丁頓吸積.從圖9我們可以看出考慮輻射壓后RQQs的愛(ài)丁頓比的范圍為0.025~0.215,它的平均值為<Lbol/LEdd>=0.11;從圖10我們可以看出考慮輻射壓后RLQs的愛(ài)丁頓比的范圍為0.04~0.85,它的平均值為<Lbol/LEdd>=0.13.從圖9和圖10可以看出考慮輻射壓后射電寧?kù)o和RLQs的愛(ài)丁頓比分布有明顯的差異性.同時(shí)由于愛(ài)丁頓比通常被用來(lái)研究類星體的演化,大多數(shù)人認(rèn)為RQQs是由RLQs的演化而來(lái)的,這兩個(gè)吸積率的分布圖也很好的證明了這一觀點(diǎn).
圖7 RLQs輻射壓黑洞質(zhì)量對(duì)發(fā)射線寬度的關(guān)系圖Fig.7 The correlation between black hole masses of RLQs with radiation pressure considered and FWHM
圖8 考慮輻射壓的愛(ài)丁頓比隨射電噪度的分布Fig.8 The distribution of Eddington ratio of RQQs and RLQs with radiation pressure considered on radio loudnessR
圖9 RQQs考慮輻射壓和沒(méi)有考慮輻射壓的吸積率的分布Fig.9 The distribution of accretion rate of RQQs with and without radiation pressure considered
圖10 RLQs考慮輻射壓和沒(méi)有考慮輻射 壓的吸積率的分布 Fig.10 The distribution of accretion rate of RLQs with and without radiation pressure considered
RQQs和RLQs在本質(zhì)上有很大的區(qū)別,造成這種區(qū)別的原因是由于取向效應(yīng)還是內(nèi)稟物理性質(zhì)目前還在 研究中[17,43-45].同 時(shí)由于射 電 噪 度和射電光度通常被用來(lái)區(qū)分射電寧?kù)o和RLQs,而且射電噪度的雙峰分布物理起源也還在不清楚.Boroson和Dreen[46]通過(guò)對(duì)PG類星體樣本研究發(fā)現(xiàn)射電噪度的雙峰分布和黑洞質(zhì)量有很強(qiáng)的相關(guān)性,對(duì)于黑洞質(zhì)量M>109M☉是RLQs,而黑洞質(zhì)量M<3×108M☉是RQQs.
Corbin[47]研究發(fā)現(xiàn)RLQs相對(duì)于RQQs有較寬的Ηβ發(fā)射線,Marconi[35]研究發(fā)現(xiàn)輻射壓對(duì)寬線云有影響,在估算黑洞質(zhì)量時(shí)如果不考慮輻射壓則黑洞質(zhì)量有可能被低估,所以提出了考慮輻射壓后黑洞質(zhì)量的估算公式.Sikora等人[15]研究了愛(ài)丁頓比和射電噪度R的關(guān)系,發(fā)現(xiàn)RLQs有高的射電噪度和吸積率,RQQs有低的射電噪度和吸積率,這也為RLQs演化為RQQs提供了證據(jù);HST觀測(cè)發(fā)現(xiàn)RLQs通常寄主在橢圓星系,RQQs通常寄主在旋渦星系;射電噪度R取決于愛(ài)丁頓比.Chiaberge[48]研究活動(dòng)星系核射電噪度的起源,發(fā)現(xiàn)射電噪度與黑洞質(zhì)量和黑洞自旋之間有關(guān)系,說(shuō)明射電噪度起源可以用這兩個(gè)參量來(lái)解釋.
通過(guò)對(duì)RQQs和RLQs考慮輻射壓黑洞質(zhì)量和吸積率分布研究發(fā)現(xiàn),他們之間的分布不相同,表明射電噪度起源和雙峰分布可能與黑洞質(zhì)量和吸積率有關(guān).根據(jù)上面的討論,我們研究了射電類星體的射電噪度和考慮輻射壓后黑洞質(zhì)量與5GHz射電光度、熱光度、紅移、射電噪度之間的相關(guān)性得到如下結(jié)論:RQQs考慮輻射壓的黑洞質(zhì)量和射電噪度、5GHz射電光度、熱光度的相關(guān)性比RLQs考慮輻射壓的黑洞質(zhì)量和射電噪度、5GHz射電光度、熱光度的相關(guān)性弱;考慮輻射壓后,RQQs的黑洞質(zhì)量和紅移的相關(guān)性比RLQs的強(qiáng);考慮輻射壓后,RQQs的黑洞質(zhì)量Mma>108M☉,而且它的吸積未超愛(ài)丁頓吸積;由于輻射壓對(duì)寬線云有影響,而大多數(shù)人認(rèn)為RQQs可能來(lái)自吸積盤(pán),這說(shuō)明寬線區(qū)和吸積盤(pán)可能有關(guān)系;考慮輻射壓的RQQs和RLQs的黑洞質(zhì)量和射電噪度、5GHz射電光度、熱光度的相關(guān)性比沒(méi)有考慮輻射壓黑洞質(zhì)量和射電噪度、5GHz射電光度、熱光度的相關(guān)性強(qiáng);考慮輻射壓后,RQQs和RLQs的黑洞質(zhì)量-射電噪度分布、黑洞質(zhì)量-Ηβ發(fā)射線寬度分布、射電噪度-愛(ài)丁頓比分布的不同說(shuō)明輻射壓對(duì)RQQs和RLQs的不同會(huì)產(chǎn)生影響.
(由于文章篇幅的限制數(shù)據(jù)表沒(méi)有附在文章中,如有需要請(qǐng)和第一作者聯(lián)系)
[1]熊定榮,張雄,鄭永剛,等.射電類星體黑洞質(zhì)量和射電特性的研究 [J].天文學(xué)報(bào),2012,53(05):369-381.
[2]LACY M,LAURENT-MUEHLEISEN S A,RIDGWAY S E,et al.The radio luminosity-black hole mass correlation for quasars from the first bright quasar survey and a"unification scheme"for radioloud and radio-quiet quasars[J].ApJ,2001 (551):L17-L21.
[3]MCLURE R J,JARVIS M J.The relationship between radio luminosity and black hole mass in optically selected quasars[J].MNRAS,2004(353):L45-L49.
[4]STOCKE J T,MORRIS S,WEYMANN R J,et al.The radio properties of the broad-absorptionline QSOs[J].ApJ,1992 (396):487-503.
[5]VISNOVSKY K L,IMPEY C D,F(xiàn)OLTZ C B,et al.Radio properties of optically selected quasars[J].ApJ,1992(391):560-568.
[6]KELLERMANN K I,SRAMEK R A,SCHMIDT M,et al.The radio structure of radio loud and radio quiet quasars in the Palomar Bright Quasars Survey[J].ApJ,1994,108(04):1163-1177.
[7]STRITTMATTER P A,HILL P,PAULINY I I K,et al.Radio observations of optically selected quasars[J].A&A,1980(88):L12-L15.
[8]KELLERMANN K I.VLA observations of objects in the Palomar Bright Quasar Survey[J].ApJ,1989,98(04):1195-1207.
[9]MILLER L,PEACOCK J A,MEAD A R G.The bimodal radio luminosity function of quasars[J].MNRAS,1990(244):207-213.
[10]CROOM S M,SMITH R J,BOYLE B J,et al.The 2dF QSO redshift survey-V.The 10kcatalogue[J].MNRAS,2001(322):L29-L36.
[11]LAOR A.On the nature of low-luminosity narrow-line active galactic nuclei[J].ApJ,2003(590):86-94.
[12]CIRASUOLO M,CELOTTI A,MAGLIOCCHETTI M,et al.Is there a dichotomy in the radio loudness distribution of quasars?[J].MNRAS,2003(346):447-455.
[13]CIRASUOLO M,MAGLIOCCHETTI M,CELOTTI A,et al.The radio-loud/radio-quiet dichotomy:news from the 2dF QSO Redshift Survey[J].MNRAS,2003(341):993-1004.
[14]WHITE R L,BECKER R H,GREGG M D,et al.The first bright quasar survey.Ⅱ.60nights and 1200spectra later[J].ApJ,2000(126):133-207.
[15]SIKORA M,STAWARZ L,LASOTA J P.Radio loudness of active galactic nuclei:observational fracts and theoretical implications[J].ApJ,2007(658):815-828.
[16]CHIABERGE M,MARCONI A.On the origin of radio loudness in active galactic nuclei and its relation ship with the properties of the central supermassive black hole[J].MNRAS,2011(416):917-928.
[17]LAOR A.On black hole masses and radio loudness in active galactic nuclei[J].ApJ,2000 (543):L111-L114.
[18]LIU Y,JIANG D R,GU M F.The jet power,radio loudness,and black hole mass in radio loud active galactic nuclei[J].ApJ,2006(637):669-681.
[19]WOO J H,URRY C M.Active galactic nucleus black hole masses and bolometric luminosities[J].ApJ,2002(579):530-544.
[20]FRANCESCHINI A,VERCELLONE S,F(xiàn)ABIAN A C.Supermassive black holes in early type galaxies:relationship with radio emission and constraints on the black hole mass function[J].MNRAS,1998(297):817-824.
[21]MCLURE R J,KUKULA M J,DUNLOP J S,et al.A comparative HST imaging study of the host galaxies of radio-quiet quasars,radio-loud quasars and radio galaxies:Paper I[J].MNRAS,1999(308):377-404.
[22]HO L C.On the relationship between radio emission and black hole mass in galactic nuclei[J].ApJ,2002(564):120-132.
[23]WANG J M,LUO B,HO L C.The connection between jets,accretion disks,and black hole mass in blazars[J].ApJ,2004(615):L9-L12.
[24]GREENE J E,HO L C.TheMBH-σ* relation in local active galaxies[J].ApJ,2006(641):L21-L24.
[25]PANESSA F,BARCONS X,BASSANI L,et al.The X-ray and radio connection in low luminosity active nuclei[J].A&A,2007(467):519-527.
[26]KORATKAR A P,GASKELL C M.Radius-luminosity and mass-luminosity relationships for active galactic nuclei[J].ApJ,1991 (370):L61-L64.
[27]KASPI S,SMITH P S,MAOZ D,et al.Measurement of the broad line region size in two bright quasars[J].ApJ,1996(471):L75-L78.
[28]KROLIK J H,HORNE K,KALLMAN T R,et al.Ultraviolet variability of NGC 5548:Dynamics of the continuum production region and geometry of the broad-line region[J].ApJ,1991 (371):541-562.
[29]KROLIK J H.Systematic errors in the estimation of black hole masses by reverberation mapping[J].ApJ,2001(551):72-79.
[30]KASPI S.Reverberation measurements for 17quasars and the size-mass luminosity relations in active galactic nuclei[J].ApJ,2000(533):631-649.
[31]李剛,劉興俊,伍林.活動(dòng)星系核吸積盤(pán)輻射的研究[J].云南師范大學(xué)學(xué)報(bào):自然科學(xué)版,2013,33(04):08-06.
[32]WANDEL A,PETERSON B M,MALKAN M A.Central masses and broad-line region sizes of acti ve galactic nuclei.Ⅰ.Co-mparing the photoionization and reverberation techniques[J].ApJ,1999(526):579-591.
[33]VESTERGAARD M.Determining central black hole masses in distant active galaxies[J].ApJ,2002(571):733-752.
[34]MCLURE R J,DUNLOP A S.On the black holebulge mass relation in active and inactive galaxies[J].MNRAS,2002 (331):795-804.
[35]MARCONI A.The effect of radiation pressure on virial black hole mass estimates and the case of narrow-line Seyfert 1galaxies[J].ApJ,2008(678):693-700.
[36]MARCONI A.On the observed distributions of black hole masses and eddington ratios from radiation pressure corrected virial indicators[J].ApJ,2009(698):L103-L107.
[37]XIE G Z.Supermassive black holes in BL Lacertae objects:estimated masses and their relation to nuclear luminosity[J].ApJ,2002(123):2352-2357.
[38]MCLURE R J,JARVIS M J.Measuring the black hole masses of high-redshift quasars[J].MNRAS,2002(337):109-116.
[39]TREMAINE S.The slope of the black hole mass versus velocity dispersion correlation[J].ApJ,2002(574):740-753.
[40]BIAN W,ZHAO Y.Timescales of soft X-ray variability and physical constraints in active galactic nuclei[J].ApJ,2003(591):733-740.
[41]BARVAINIS R.Free-free emission and the big blue bump in active galactic nuclei[J].ApJ,1993(412):513-523.
[42]VENTERS T M,PAVLIDOU V,REYES L C.The extragalactic background light absorption feature in the blazar component of the extragalactic gamma-ray background[J].ApJ,2009 (703):1939-1946.
[43]ANTONUCCI R.Unified models for active galactic nuclei and quasars[J].A&A,1993 (31):473-521.
[44]MARECKI A,SWOBODA B.The transition from quasar radio-loud to radio-quiet state in the frame work of the black hole scalability hypothesis[J].A&A,2011(525):6-13.
[45]董霞,張皓輝,熊定榮,等.活動(dòng)星系核中黑洞質(zhì)量與宇宙學(xué)紅移的研究[J].云南師范大學(xué)學(xué)報(bào):自然科學(xué)版,2013,33(01):09-04.
[46]BOROSON T A,GREEN R F.The emission-line properties of low-redshift quasi-stellar objects[J].ApJ,1992(80):109-135.
[47]CORBIN M R.The emission-line properties of low-redshift quasi-stellar objects.Ⅱ.The relation to radio type[J].ApJS,1997(113):245-267.
[48]CHIABERGE M,MARCONI A.On the origin of radio loudness in active galactic nuclei and its relationship with the properties of the central supermassive black hole[J].MNRAS,2011(416):917-927.