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arXiv · 0704.0133

PAH emission and star formation in the host of the z~2.56 Cloverleaf QSO

D. Lutz·E. Sturm·L. J. Tacconi·E. Valiante·M. Schweitzer·H. Netzer·R. Maiolino·P. Andreani·O. Shemmer·S. Veilleux
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Abstract

We report the first detection of the 6.2micron and 7.7micron infrared `PAH' emission features in the spectrum of a high redshift QSO, from the Spitzer-IRS spectrum of the Cloverleaf lensed QSO (H1413+117, z~2.56). The ratio of PAH features and rest frame far-infrared emission is the same as in lower luminosity star forming ultraluminous infrared galaxies and in local PG QSOs, supporting a predominantly starburst nature of the Cloverleaf's huge far-infrared luminosity (5.4E12 Lsun, corrected for lensing). The Cloverleaf's period of dominant QSO activity (Lbol ~ 7E13 Lsun) is coincident with an intense (star formation rate ~1000 Msun/yr) and short (gas exhaustion time ~3E7yr) star forming event.

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D. Lutz, E. Sturm, L. J. Tacconi, E. Valiante, M. Schweitzer, H. Netzer, R. Maiolino, P. Andreani, O. Shemmer, S. Veilleux. 2007-04-02. PAH emission and star formation in the host of the z~2.56 Cloverleaf QSO. https://doi.org/10.1086/518537

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