Multiple CO Transitions, Ci, and HCN from the Cloverleaf Quasar

New millimeter-wavelength emission lines are reported for the Cloverleaf(H1413+117), a gravitationally lensed quasar at redshift 2.56. Highsignal-to-noise ratio spectra of four lines in CO (J=3-2, J=4-3, J=5-4, andJ=7-6) have been obtained and are modeled using an escape probabilityformalism. The line brightness temperatures are flat or rising between CO(3-2)and CO(4-3) and then drop to the CO(5-4) and CO(7-6) lines; this falloffsuggests that the optical depths in the CO lines are modest (tau_{4-3} < 3),and that the gas is relatively warm (T ~ 100 K) and dense (n_H2 > 3 X 10^3cm^{-3}). The neutral carbon fine structure line CI(3P1-3P0) was detected withmoderate SNR on two separate occasions, and appears secure. The HCN(4-3) lineis somewhat more tentative, as it was observed only once and detected withmoderate SNR. However, its brightness ratio of 0.25 relative to the CO(4-3)line is very similar to the ratio seen in luminous infrared galaxies. Thedetectability of the Cloverleaf in molecular and neutral atomic transitions islargely due to high emissivity of the gas and magnification from gravitationallensing, rather than an extremely large mass of gas.Comment: 14 pages of text, plus two figures. Requires aaspp4.sty, included. To be published in the Astrophysical Journa