Astrophysical Research
Active Galactic Nuclei
In the background of the image is the Seyfert galaxy NGC 1068, obtained with the Hubble Space Telescope. This galaxy is located at ~45 million light-years away. The red regions in their spiral arms are newborn star-forming regions. In the nucleus lies the supermassive black hole surrounded by the accretion disk and the dusty torus.
I am expert on the study of the nuclear dust in active galactic nuclei, for which I have used infrared images and spectra from ground-based and space telescopes.
The active galactic nuclei (AGN) are among the most powerful and exciting objects in the Universe. These objects can emit along all the electromagnetic spectrum and, its nuclear optical spectrum is dominated by a set of high ionization emission lines (ionization potential > 54 eV). The high energetic photons produced during the accretion of material onto the central supermassive black hole (~10^6-10^10 M_{\odot}, SMBH) excite these emission lines. There is a large variety of AGNs, mainly classified according to the detection (type 1) or not (type 2) of at least one broad emission line (FWHM~10^3-10^4 kms^{-1}). The broad emission lines are produced in a region of gaseous clouds that surround the accretion disk and SMBH, called the broad-line region (BLR). The unification scheme of AGN proposes that the BLR is hidden from the line of sight (LOS) of the observer by a putative dusty torus that surrounds the central engine on scales of a few pc (e.g., Rowan-Robinson 1977, Antonucci 1993). The narrow emission lines come from the narrow line region, which extended several kpc from the dusty torus. The putative dusty torus/disk represents a key piece in the classification of AGNs. Therefore, a clear characterization of their physical properties (e.g, size, geometry, and composition) will improve our understanding of AGNs as a key phase in the galaxy evolution scenario.
To know more on my research go to The dusty torus in Seyfert and Quasars
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