Abstract
We report the first detection of the 6.2 and 7.7 μm infrared polycyclic aromatic hydrocarbon (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 ULIRGs and in local PG QSOs, supporting a predominantly starburst nature of the Cloverleaf s huge far-infrared luminosity (5.4 × 1012 L⊙, corrected for lensing). The Cloverleaf's period of dominant QSO activity (L Bol ∼ 7 × 1013 L⊙) is coincident with an intense (star formation rate ∼ 1000 M⊙ yr -1) and short (gas exhaustion time ∼ 3 × 107 yr) star-forming event.
Original language | English |
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Pages (from-to) | L25-L28 |
Journal | Astrophysical Journal |
Volume | 661 |
Issue number | 1 II |
DOIs | |
State | Published - 20 May 2007 |
Keywords
- Galaxies: active
- Galaxies: starburst
- Infrared: galaxies