The molecular gas content of ULIRG type 2 quasars at z łt 1}

We present new results of CO(1-0) spectroscopic observations of four Sloan Digital Sky Survey (SDSS) type 2 quasars (QSO2) at z \~{} 0.3, observed with the 30-m IRAM radio telescope. The QSO2 have infrared luminosities in the ultra-luminous infrared galaxies (ULIRG) regime. We confirm the CO(1-0) detection in one of our four QSO2, SDSS J1543-00, with L'$_{CO}$ and M$_{H_2}$ (1.2 {\plusmn} 0.2) {\times} 10$^{10}$ K km s$^{-1}$ pc$^{2}$ and (9.4 {\plusmn} 1.4) {\times} 10⁹ M $_{&sun;}$, respectively. The full width at half maximum (FWHM) of the CO(1-0) line is =575 {\plusmn} 102 km s$^{-1}$. No CO(1-0) emission is detected in SDSS J0903+02, SDSS J1337-01, SDSS J1520-01 above 3 sigma, yielding upper limits on M(H₂) \~{} 9.6, 4.3 and 5.1 {\times} 10⁹ M$_{&sun;}$, respectively. We expand previous studies of the molecular gas content of intermediate z QSO2 into the ULIRG regime. Taking into account nine QSO2 at z \~{} 0.3-1.0 from the literature, we discuss the location of the 13 ULIRG QSO2 at z łt} 1 with available L'$_{CO}$ measurements in the L'$_{CO}$ vs. z and L'$_{CO}$ vs. L$_{FIR}$ diagrams, in comparison with other QSO1 and ULIRG star forming samples. Based on observations carried out with the IRAM 30 m radiotelescope.