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

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

2007-11-22

arxiv.org/abs/0711.3499v1

Astronomy and Astrophysics

Astrophysics

7 figures, to appear in A&A

Scientific paper

10.1051/0004-6361:20078176

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.

Affiliated with

Also associated with

No associations

Rating

The unusual UV continuum of quasar Ton 34 and the possibility of crystalline dust absorption does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The unusual UV continuum of quasar Ton 34 and the possibility of crystalline dust absorption, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The unusual UV continuum of quasar Ton 34 and the possibility of crystalline dust absorption will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-310113