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The First Stars and Galaxies: Challenges for the Next Decade Participants
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Talk
Title: Molecular Line Detection in High-z AGN by ALMA Author(s): Dominik Schleicher Abstract: The upcoming mm/sub-mm telescope ALMA will provide a unique opportunity to probe the dynamics and chemistry of active nuclei at high redshift with unprecedented sensitivity and angular resolution. ALMA has the capability to resolve both the starburst dominated extended regions and the central X-ray (AGN) dominated region. Close to an accreting black hole the CO line SED rises up to the CO (15-14) transition or higher. I will show the characteristic dependence of various lines on X-ray luminosity, density and cloud column density, with special emphasis on the z=6.42 quasar. I will further discuss earlier evolutionary stages concerning the formation of intermediate-mass black holes, in massive primordial halos where cooling by molecular hydrogen is suppressed due to a strong soft-UV radiation field and Lyman alpha photon trapping. Still, additional cooling channels like the hydrogen 2s-1s and 3-2 transitions, as well as H$^-$ formation and H$_2$ collisional dissociation cooling lead to a modest temperature decrease during the collapse, which may lead to fragmentation in the disk around the massive clump.
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