The far-UV break in The far-UV break in quasar SEDs, dust?quasar SEDs, dust?

Luc BinetteLuc BinetteSinhue Haro-CorzoSinhue Haro-CorzoYair KrongoldYair KrongoldAnja AndersenAnja Andersen

Xi’an, October 2006Xi’an, October 2006

Note: the text accompanying this talk can

Note: the text accompanying this talk can

be found at astro-ph/0611011

be found at astro-ph/0611011

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

rest

FFH

ST/S

DSS

Telfer et al. 2002

SLOAN

ratio: HST/SDSS

HST

Ly

Ly

main

problem: composite SED too softproblem: composite SED too soft• Korista et al. 1997 Korista et al. 1997

showed the difficulty of showed the difficulty of reproducing HeII, NV reproducing HeII, NV and CIV equivalent and CIV equivalent widths assuming a soft widths assuming a soft SED, similar to the SED, similar to the Telfer compositeTelfer composite

• photoionization models photoionization models nowadays use a much nowadays use a much harder SEDharder SED– SEDs that peak beyond SEDs that peak beyond

20eV20eV

• analysis of X-ray and analysis of X-ray and EUV spectra of 11 EUV spectra of 11 individualindividual quasars quasars revealed that the soft X-revealed that the soft X-ray excess does not ray excess does not correspond to an correspond to an extrapolation of the far-extrapolation of the far-UV powerlawUV powerlaw– Haro-Corzo et al. Haro-Corzo et al.

(submitted)(submitted)

X-ray & far-UV connection

• far-UV does not extrapolate smoothly into X-rays– Haro-Corzo et

al. (submitted)– see poster #338

11 quasars11 quasars

principal

HI : LyHI : Ly …+ …+ Lyman continuum

dust dust absorptionabsorption

inter

galac

tic

inter

galac

tic

abso

rptio

n

abso

rptio

n

intrin

sic

intrin

sic

scre

ensc

reen dis

k dis

k ph

otos

pher

e

phot

osph

ere

acce

lerate

d

acce

lerate

d

ouflo

wou

flow

AA BB CC DD

11 22 33 44

•not needednot needed•not not usefuluseful

•fit so-sofit so-so•too redtoo red

•too sharp too sharp edgeedge

•jump not jump not seenseen

•too much too much dustdust

Eastman, MacAlpine, Richstone

(1983)

1.1. intrinsic crystalline C dust, promising:intrinsic crystalline C dust, promising:– polarization polarization vsvs lambda lambda

• should model scattering using transfer code should model scattering using transfer code – René GoosmannRené Goosmann

– optical reddeningoptical reddening• SMC-like dust?SMC-like dust?• universal SED?universal SED?

– Sinhue Haro Corzo et al. (submitted) Sinhue Haro Corzo et al. (submitted) – atomic gas absorptionatomic gas absorption

• in process (Ton 34)in process (Ton 34)– infrared re-emissioninfrared re-emission

• rules out meteoritic flavorrules out meteoritic flavor• in progress: Anja Andersenin progress: Anja Andersen

– accretion disk photosphereaccretion disk photosphere• accretion disk code neededaccretion disk code needed

2.2. accelerated outflow?accelerated outflow?– speculative but tantalizingspeculative but tantalizing

conclusionsconclusions

GOAL: to

GOAL: to unmask the

unmask the accretion disk

accretion disk

(ionizing) SED

(ionizing) SED

mainCBLy ValleyACwarm

1- extragalactic HI absorption (WHIM)

F

Binette et al. 2003, ApJ 590, 58 Binette et al. 2003, ApJ 590, 58

(Å) rest-framerest-frame (Å) observer-frameobserver-framemain

predicted jump

predicted jump

NOTNOT observed

observed

A-intergalactic dust

F

==0.6

0.6rest-frame

EUV vs. z ; Telfer et al.

EUV z redshift

Binette Binette et al.et al. 2005, ApJ 631, 661 2005, ApJ 631, 661

•requires too requires too much dust much dust •excludes excludes other types other types of dustof dust

main

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-framerest-frame

FF

Zheng 97

Hubeny Hubeny et al.et al. (2000) (2000)

main

4-accelerated outflow

(Hz)F

Eastman, MacAlpine, Richstone (1983)Eastman, MacAlpine, Richstone (1983)

He 2357He 23574342 z=2.8854342 z=2.885

Reimers et al.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

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 3200 Å

crystalline C

amorphous C

SMC-like

fits UV break in individual quasar spectra

• example: PG1148+459

• assumes curve D3– cubic nanodiamond

grains only– size distr. (a3.5)

• range 3200 Å

– Haro-Corzo et al. (submitted)

main log log

log

Flo

g F Haro-Corzo et Haro-Corzo et

al. 2006al. 2006

examples of quasars consistent with an E-UV recovery at 18.5 eV (670Å)

1008 0232 1307

ApJ (2005) 631, 661 ApJ (2005) 631, 661

• PG 1008+1319 zq=1.287• Pks 0232-04 zq=1.45• HS 1307+4617 zq=2.129

main

•extinction predicts a flux recovery in the extreme UV

NUV

FU

VFU

V

HST

¤

Ton 34: extremely UV deficient

• Telfer’s sample, UV break ~1100Å– 2 spectral indices

– <NUV> 0.7

– <FUV> 1.7

• Ton 34 – extreme UV break

NUV=0.3 FUV=5.3 (TZ02)

línea línea FUVFUV ==

NUVNUV

NUV

FUV

main CB disk

big blue bump

2F

F

log rest

SLOAN 2001

log

F

moyenne de 2200 spectres

Grosse Bosse Bleue (BBB)

components encountered in quasar SEDs

thermal(disk)

inverse Compton(jet)

Lichti et al. (1994)

synchrotron(jet)

F

infraredinfraredbumpbump

main

NGC5548NGC5548

HST-FOSKorista & Goad

ton34 & ngc5548

• HST-STIS(Crenshaw et al. 2003)

• warm absorber• N(H)~5 1020 cm-2

• T~ few 104 K