DUST IN THE POLAR REGION AS A MAJOR CONTRIBUTOR TO THE INFRARED EMISSION OF ACTIVE GALACTIC NUCLEI
DUST IN THE POLAR REGION AS A MAJOR CONTRIBUTOR TO THE INFRARED EMISSION OF ACTIVE GALACTIC NUCLEI
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极地地区的尘埃是活动星系核红外发射的主要贡献者
DOI：
10.1088/0004-637x/771/2/87
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Tristram
中科院分区：
文献类型：
--
作者：
Hönig;Kishimoto;Tristram
活动星系核(AGN)周围的尘埃分布在广泛的空间尺度上，可以在红外(IR)中观察到。通常认为，在微秒尺度上的分布在围绕吸积盘和宽线区域的赤道平面上形成了几何和光学厚度的实体--称为“尘埃环面”--它发射出亚弧秒尺度的大部分红外辐射，并引起与方位有关的遮蔽。然而，最近对两个模糊(类型2)活动星系核在这些小尺度上具有前所未有的位置角(PA)和基线覆盖的红外干涉测量研究表明，这些天体中的大多数中红外发射在极方向上拉长。这些观测结果很难与标准的解释相一致，即活动星系核中大部分秒尺度的中红外辐射来自环面，并挑战了使用简单的环面模型来模拟宽带红外辐射的合理性。在这里，我们报告了对NGC 3783中未遮挡的(类型1)活动星系核的详细干涉测量观测，使我们能够高精度地限制中红外发射的大小、延伸和方向。中红外发射的特征是向位置角PA−52强烈伸长，与极轴(PA−45)紧密对准。在(2 0.0±3.0)ma×(6.7±1.0)ma或(4.2 3±0.6 3)pc×(1.42±0.2 1)pC的12.5μm处测得半光半径，对应于从近红外混响图谱推断的rIn=0.061 pC的内尘埃半径为(6 9.4±10.8)rIn×(2 3.3±3.5)rin。这意味着轴比为3：1，其中约60%-90%的8-13μm发射与极性拉长的分量有关。最近用近红外干涉法分辨的热尘埃发射很可能与中红外发射源错位，这也在高角分辨率光谱能量分布中看到的两个明显的3-5μm和20μm凸起中找到了对应关系。在此基础上，我们确定了热尘和暖尘组分的覆盖系数
Dust around active galactic nuclei (AGNs) is distributed over a wide range of spatial scales and can be observed in the infrared (IR). It is generally assumed that the distribution on parsec scales forms a geometrically and optically thick entity in the equatorial plane around the accretion disk and broad-line region—dubbed" dust torus"—that emits the bulk of the subarcsecond-scale IR emission and gives rise to orientation-dependent obscuration. However, recent IR interferometry studies with unprecedented position angle (PA) and baseline coverage on these small scales in two obscured (type 2) AGNs have revealed that the majority of the mid-IR emission in these objects is elongated in the polar direction. These observations are difficult to reconcile with the standard interpretation that most of the parsec-scale mid-IR emission in AGNs originate from the torus and challenges the justification of using simple torus models to model the broadband IR emission. Here, we report detailed interferometry observations of the unobscured (type 1) AGN in NGC 3783 that allow us to constrain the size, elongation, and direction of the mid-IR emission with high accuracy. The mid-IR emission is characterized by a strong elongation toward position angle PA− 52, closely aligned with the polar axis (PA− 45). We determine half-light radii along the major and minor axes at 12.5 μm of (20.0±3.0) mas×(6.7±1.0) mas or (4.23±0.63) pc×(1.42±0.21) pc, which corresponds to intrinsically scaled sizes of (69.4±10.8) r in×(23.3±3.5) r in for the inner dust radius of r in= 0.061 pc as inferred from near-IR reverberation mapping. This implies an axis ratio of 3: 1, with about 60%–90% of the 8–13 μm emission associated with the polar-elongated component. It is quite likely that the hot-dust emission as recently resolved by near-IR interferometry is misaligned with the mid-IR emitting source, which also finds a correspondence in the two distinct 3–5 μm and 20 μm bumps seen in the high angular resolution spectral energy distribution (SED). Based on this SED, we determine covering factors for the hot and warm dust components of
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DOI：
10.1088/0004-637x/755/2/149
发表时间：
2012-06
期刊：
The Astrophysical Journal
影响因子：
--
作者：
S. Hoenig;M. Kishimoto;R. Antonucci;A. Marconi;M. Prieto;K. Tristram;Gerd Weigelt Ucsb;Mpifr;U. Firenze;Iac
通讯作者：
S. Hoenig;M. Kishimoto;R. Antonucci;A. Marconi;M. Prieto;K. Tristram;Gerd Weigelt Ucsb;Mpifr;U. Firenze;Iac
NGC 1068窄线区电离结构及其与扩展射电发射的关系
DOI：
--
发表时间：
1997
期刊：
影响因子：
--
作者：
A. Capetti;D. Axon;F. Macchetto
通讯作者：
F. Macchetto
NGC 1068 从近红外到射电的高空间分辨率 SED - 理清热和非热贡献
影响因子：
6.5
作者：
S. Hoenig;M. Prieto;T. Beckert
通讯作者：
T. Beckert
影响因子：
6.5
作者：
S. Hoenig;Makoto Kishimoto Ucsb;Mpifr
通讯作者：
Mpifr
影响因子：
6.5
作者：
D. Asmus;D. Asmus;P. Gandhi;A. Smette;S. Hönig;W. Duschl;W. Duschl
通讯作者：
D. Asmus;D. Asmus;P. Gandhi;A. Smette;S. Hönig;W. Duschl;W. Duschl