The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245
The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245
复制标题
塞弗特星系 NGC 2992 和相互作用系统 Arp 245 的核发射和扩展红外发射
DOI：
10.1093/mnras/stv338
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发表时间：
2015
影响因子：
4.8
通讯作者：
N. Levenson
中科院分区：
文献类型：
--
作者：
I. García;I. García;C. R. Almeida;C. R. Almeida;J. Acosta;J. Acosta;A. Alonso;A. Alonso;M. S'anchez;M. Castillo;M. Pereira;P. Esquej;O. González;O. González;O. González;T. Díaz;T. Díaz;P. Roche;S. Fisher;M. Pović;A. P. Garćıa;A. P. Garćıa;I. Valtchanov;C. Packham;N. Levenson
我们给出了用双子座北方望远镜和Gran望远镜(GTC)获得的Seyfert 1.9星系NGC2992的亚分辩秒红外(IR)成像和中IR(MIR)光谱观测。N波段图像显示出微弱的延伸发射到∼3kpc，在GTC/CanariCam7.5-13μm光谱中检测到的多环芳烃特征表明，这种延伸发射的大部分是恒星形成所加热的尘埃。我们还报道了由斯皮策空间望远镜和赫歇尔空间天文台拍摄的相互作用系统Arp 245的弧秒分辨率MIR和远红外成像。利用这些数据，我们用不同的方法得到了核通量，发现我们只能从20-25μm的亚弧秒数据中恢复核通量，在那里活动星系核(AGN)发射占主导地位。我们用块状环面模型对NGC2992的核红外光谱能量分布进行了拟合，其中包括GTC/CanariCam核光谱(∼50pC)。然后，我们用最优拟合环模型分解了活动星系核和恒星暴中的Spitzer/IRS5-30μm谱(∼630PC)，并使用了不同的恒星暴模板。我们发现，在较短的MIR波段，恒星爆发成分占主导地位( Per Cent在6μm处)，活动星系核成分在20 m处达到90 /μCent。我们最终获得了Arp245系统不同成分的尘埃质量、温度和恒星形成率，并对NGC2992和NGC2993找到了相似的值。这些测量值在报道的其他相互作用系统在相互作用的第一阶段的测量范围内。
We present subarcsecond resolution infrared (IR) imaging and mid-IR (MIR) spectroscopic observations of the Seyfert 1.9 galaxy NGC 2992, obtained with the Gemini North Telescope and the Gran Telescopio CANARIAS (GTC). The N-band image reveals faint extended emission out to ∼3 kpc, and the polycyclic aromatic hydrocarbon features detected in the GTC/CanariCam 7.5–13 μm spectrum indicate that the bulk of this extended emission is dust heated by star formation. We also report arcsecond resolution MIR and far-IR imaging of the interacting system Arp 245, taken with the Spitzer Space Telescope and the Herschel Space Observatory. Using these data, we obtain nuclear fluxes using different methods and find that we can only recover the nuclear fluxes obtained from the subarcsecond data at 20–25 μm, where the active galactic nuclei (AGN) emission dominates. We fitted the nuclear IR spectral energy distribution of NGC 2992, including the GTC/CanariCam nuclear spectrum (∼50 pc), with clumpy torus models. We then used the best-fitting torus model to decompose the Spitzer/IRS 5–30 μm spectrum (∼630 pc) in AGN and starburst components, using different starburst templates. We find that, whereas at shorter MIR wavelengths the starburst component dominates (64 per cent at 6 μm), the AGN component reaches 90 per cent at 20 μm. We finally obtained dust masses, temperatures and star formation rates for the different components of the Arp 245 system and find similar values for NGC 2992 and NGC 2993. These measurements are within those reported for other interacting systems in the first stages of the interaction.