Extreme CII emission in type 2 quasars at z~2.5: a signature of kappa-distributed electron energies?

We investigate the flux ratio between the 1335 A and 2326 A lines of singly ionized carbon in the extended narrow line regions of type 2 quasars at z~2.5. We find the observed CII 1335 / CII] 2326 flux ratio, which is not sensitive to the C/H abundance ratio, to be often several times higher than predicted by the canonical AGN photoionization models that use solar metallicity and a Maxwell-Boltzmann electron energy distribution. We study several potential solutions for this discrepancy: low gas metallicity, shock ionization, continuum fluorescence, and kappa-distributed electron energies. Although we cannot definitively distinguish between several of the proposed solutions, we argue that a kappa distribution gives the more natural explanation. We also provide a grid of AGN photoionization models using kappa-distributed electron energies.Comment: 6 pages, 1 figure, 3 tables. Accepted for publication in MNRA

Inflation and Relative Price Dispersion in Canada: An Empirical Assessment

The authors investigate empirically the relationship between different aspects of inflation and relative price dispersion in Canada using a Markov regime-switching Phillips curve. They examine three theories that explain movements in relative price dispersion: the signal extraction model, the extension of the signal extraction model, and the menu cost model. The authors show that expected inflation, which is captured by the menu cost model, is the aspect of inflation that is most closely associated with relative price dispersion. Furthermore, this result seems robust to different specifications. The authors, however, cannot completely discard inflation uncertainty (the signal extraction model), especially when using core inflation. They also observe a strong asymmetry regarding the impact of positive and negative unexpected inflation on relative price dispersion using total inflation, but this asymmetry is not observed for core inflation. This suggests that the strong asymmetry arises mainly from the presence of components typically associated with supply shocks, and not from the presence of downward nominal rigidities, as Aarstol (1999) proposes, following Ball and Mankiw (1992a,b).Inflation and prices

The unusual UV continuum of quasar Ton 34 and the possibility of crystalline dust absorption

Luminous quasars are known to display a sharp steepening of the continuum near 1100A. This spectral feature is not well fitted by current accretion disk models, unless comptonization of the disk emission is invoked. Absorption by carbon crystalline dust has been proposed to account for this feature. Ton 34 (z=1.928) exhibits the steepest far-UV decline (F_nu prop nu^{-5.3}) among the 183 quasar HST-FOS spectra analyzed by Telfer et al. It is an ideal object to test the crystalline dust hypothesis as well as alternative interpretations of the UV break. We reconstruct the UV spectral energy distribution of Ton 34 by combining HST, IUE and Palomar spectra. The far-UV continuum shows a very deep continuum trough, which is bounded by a steep far-UV rise. We fit the trough assuming nanodiamond dust grains. Extinction by carbon crystalline dust reproduces the deep absorption trough of Ton 34 reasonably well, but not the observed steep rise in the extreme UV. We also study the possibility of an intrinsic continuum rollover. The dust might be part of a high velocity outflow (13000 km/s), which is observed in absorption in the lines of CIV, OVI, NV and Ly_alpha.Comment: 7 figures, to appear in A&