2. The far-UV break in quasar SEDs, dust? Luc Binette Sinhue Haro-Corzo Yair Krongold Anja Andersen Xi’an, October 2006 Note: the text accompanying this talk can be found at astro-ph/0611011

3. correcting for intergalactic gas Telfer, Zheng, Kriss et al. derived a composite SED using 332 HST- FOS spectra of 183 quasars they corrected for the Lyman valley –each spectrum was divided by the appropriate Transmission function –comparison with SLOAN confirms strategy: coincidence of the discontinuities with position of Ly  and Ly  rest F HST/SDSS Telfer et al. 2002 SLOAN ratio: HST/SDSS HST Ly  Ly  main

4. problem: composite SED too soft Korista et al. 1997 showed the difficulty of reproducing HeII, NV and CIV equivalent widths assuming a soft SED, similar to the Telfer compositeKorista et al. 1997 showed the difficulty of reproducing HeII, NV and CIV equivalent widths assuming a soft SED, similar to the Telfer composite photoionization models nowadays use a much harder SEDphotoionization models nowadays use a much harder SED –SEDs that peak beyond 20eV analysis of X-ray and EUV spectra of 11 individual quasars revealed that the soft X- ray excess does not correspond to an extrapolation of the far- UV powerlaw –Haro-Corzo et al. (submitted)

5. X-ray & far-UV connection far-UV does not extrapolate smoothly into X- rays –Haro-Corzo et al. (submitted) –see poster #338 11 quasars

6. principal HI : Ly  …+ HI : Ly  …+ Lyman continuum dust absorption intergalactic absorption intrinsic screen disk photosphere accelerated ouflow AAAA BBBB CCCC DDDD 1111 2222 3333 4444 not needednot needed not usefulnot useful fit so-sofit so-so too redtoo red too sharp edgetoo sharp edge jump not seenjump not seen too much dusttoo much dust Eastman, MacAlpine, Richstone (1983)

7. 1.intrinsic crystalline C dust, promising: –polarization vs lambda should model scattering using transfer codeshould model scattering using transfer code –René Goosmann –optical reddening SMC-like dust?SMC-like dust? universal SED?universal SED? –Sinhue Haro Corzo et al. (submitted) –atomic gas absorption in process (Ton 34)in process (Ton 34) –infrared re-emission rules out meteoritic flavorrules out meteoritic flavor in progress: Anja Andersenin progress: Anja Andersen –accretion disk photosphere accretion disk code neededaccretion disk code needed 2.accelerated outflow? –speculative but tantalizing conclusions GOAL: to unmask the accretion disk (ionizing) SED main CBLy ValleyACwarm

8. 1- extragalactic HI absorption (WHIM) F Binette et al. 2003, ApJ 590, 58 (Å) rest-frame observer-frame main predicted jump NOT observed

9. A-intergalactic dust F  =  0.6 rest-frame  EUV vs. z ; Telfer et al.  EUV z redshift Binette et al. 2005, ApJ 631, 661 requires too much dustrequires too much dust excludes other types of dustexcludes other types of dust main

10. 3- problem of accretion disk SED accretion disks predict break near Lyman limit –but does not quite fit observed break of composite SED –SED too soft to account for high ionization emission lines rest-frame rest-frame F Zheng 97 Hubeny et al. (2000) main

11. 4-accelerated outflow (Hz) F Eastman, MacAlpine, Richstone (1983) He 2357  4342 z=2.885 Reimers et al. main see Eastman, MacAlpine & Richstone (1983) gas condensations accelerated up to 0.8 c model should be modified –need to blueshift break by 0.1c –must produce a recovery in far-UV

12.  B- crystalline carbon dust grains Shang et al. (2005) explored SMC-like and ISM dust such dust does NOT fit UV break crystalline carbon grains –extinction has sharp peak in the far-UV –can fit UV break –found in stellar disk –formation processes: nucleation of organic ice mixtures by UV photolysis (Kouchi et al. 2005) UV conversion of PAH clusters (Duley & Grishko 2001). … main size 3  200 Å crystalline C amorphous C SMC-like

13. fits UV break in individual quasar spectra example: PG1148+459 assumes curve D3 –cubic nanodiamond grains only –size distr. (a  3.5 ) range 3  200 Å –Haro-Corzo et al. (submitted) main log log log F log F Haro-Corzo et al. 2006

14. examples of quasars consistent with an E-UV recovery at 18.5 eV (670Å) 100802321307 ApJ (2005) 631, 661 PG 1008+1319 z q =1.287 Pks 0232-04 z q =1.45 HS 1307+4617 z q =2.129 main extinction predicts a flux recovery in the extreme UV

15.  NUV  FUV HST ¤ Ton 34: extremely UV deficient Telfer’s sample, UV break ~1100Å –2 spectral indices –   0.7 –   1.7 Ton 34 –extreme UV break –  NUV =  0.3 –  FUV =  5.3 (TZ02) línea  FUV =  NUV  NUV  FUV main CBdisk

16. big blue bump log rest SLOAN 2001 log F moyenne de 2200 spectres Grosse Bosse Bleue (BBB)

17. components encountered in quasar SEDs thermal (disk) inverse Compton (jet) Lichti et al. (1994) synchrotron (jet) F infrared bump main

18. NGC5548 HST-FOS Korista & Goad ton34 & ngc5548 HST-STIS (Crenshaw et al. 2003) warm absorber N(H)~5 10 20 cm -2 T~ few 10 4 K