Revisiting the complex nuclear region of NGC 6240 with Chandra

التفاصيل البيبلوغرافية
العنوان: Revisiting the complex nuclear region of NGC 6240 with Chandra
المؤلفون: Fabbiano, G., Paggi, A., Karovska, M., Elvis, M., Nardini, E., Wang, Junfeng
سنة النشر: 2020
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
الوصف: We present a reanalysis of the cumulative ACIS S Chandra data set pointed at the double AGNs of the NGC 6240 merging galaxy, focusing on the hard energy bands containing the hard spectral continuum (5.5-5.9 keV), the redshifted Fe I K alpha line (6.0-6.4 keV), and the redshifted Fe XXV line (6.4-6.7 keV). We have used to the full the Chandra telescope angular resolution, and we have modeled the Chandra PSF by comparing pre-flight calibration model to the data for the two bright AGNs. With two complementary approaches: (1) studying the residuals after PSF subtraction, and (2) producing reconstructed Expectation through Markov Chain Monte Carlo (EMC2) images, we are able to resolve structures extending from 1 kpc to <200 pc in the S AGN. The latter are within the sphere of influence of this BH. We find significant extended emission in both continuum and Fe lines in the 2'' (1 kpc) region surrounding the nuclei, in the region between the N and S AGN, and in a sector of PA 120-210 deg. extending to the SE from the centroid of the S AGN surface brightness. The extended Fe I K alpha emission is likely to originate from fluorescence of X-ray photons interacting with dense molecular clouds, providing a complementary view to recent high-resolution ALMA studies. The non-thermal emission is more prevalent in the region in between the two active X-ray nuclei, and in the N AGN. We do not find strong evidence of X-ray emission associated with the 3rd nucleus recently proposed for NGC 6240.
Comment: in press on The Astrophysical Journal
نوع الوثيقة: Working Paper
DOI: 10.3847/1538-4357/abb5ad
URL الوصول: http://arxiv.org/abs/2009.01824
رقم الأكسشن: edsarx.2009.01824
قاعدة البيانات: arXiv
الوصف
DOI:10.3847/1538-4357/abb5ad