problem of weak radio emission

1. FR II or FR I ? problem of weak radio emission

2. The origin of weak radio emission in Type-2 radio-quit quasars - the new era of mJy VLBI observations - Hans-Rainer Klöckner Alejo Martínez-Sansigre Mike Garrett Steve Rawlings Paul Alexander David Green Julia Riley 8th European VLBI Network Symposium, Torun, Poland

3. Intro - the sample type I good understanding optical LF z ~ 2 population of obscured radio quit quasars postulated from hard X-ray background  give hint of black-hole growth Spitzer FLS VLA-B Condon et al. AJ 2003 ~# 700 deg-2 S3.6 mm ≤ 45 mJy  z > 2: ~1.2 m exclude type I S24 mm > 300 mJy  z > 2: L ≥ 0.2 L* Quasar break luminosity 2 mJy ≥ S1.4GHz ≥ 350mJy  Exclude ULIRG & FRII [Martínez-Sansigre et al. Nature 2005] • population of 21 distant type II quasars in 3.8 sq.degrees

4. Intro - sub-sample Martínez-Sansigre et al. MNRAS 2006 Normalized 100%; < 2000 kms-1 36% 9% 9% 4% • population of 11 distant type II quasars in 3.8 deg2 redshift range 2 - 4.169 Z > 2: redshifts: 7 spec & 3 photo [AMS01, AMS09,AMS21], 1 not obs [AMS15] Optical mR = 23.8 - 25.3  L1.4GHz FRI FRII @ 2.5E24 W / (Hz sr) [Ledlow & Owen 1996] composite spectrum

5. the idea HDF: J123642 + 621331 z = 4.424 WSRT 489 mJy  VLA-A 467 mJy  MERLIN 472 mJy  EVN 248 mJy EVN 1.4 GHz[rms 40mJy; Garrett et al. 2001] MERLIN 1.4 GHz[Muxlow et al. 2005] dusty , starforming galaxy + embedded AGN

6. EVN observations 3 x 12 hrs in October & November 2005 EF, (WB), JB, ON, MC, NT, TR, UR, SH J1722+5856 Correlated: December / January 2005/2006 Bob, Lisa, Rebeca 8 IF 32 channels 0.5 MHz per channel  128 MHz band !!! MK5 recording system 9 x 3275 Gbytes !!!

7. EVN observing strategy 8 IF, 4-28 channels 200 channels  123.5 MHz J1722+5856 centre frequency 1658.24 MHz o separation ~2 deg flux recovered J1722+6105 W171156 [131 mJy] [15.52 mJy ] o [VLBA 17.031.3 mJy ]

8. results rms ~ 26 Jy; 6-7 rms peak  8 out of 11 72% [AMS01, AMS06, AMS17] AMS03 AMS19 AMS05 AMS09 AMS15 AMS12 AMS21 AMS16

9. VLBI surveys NOAO Bootes Field: 0.28 deg2 3 out of 24 & 6 out of 37  detection rate sub-mJy is 8+4-5 % and 29+11-12 % mJy Garrett et al. ApJ 2004 HDF + HFF : ~0.5 deg2 2 out of 92 [2%] for [rms ~33mJy] Garrett et al. A&A 2000 HDF : ~0.5 deg2 4 out of 7 [57%] for [rms ~7mJy] Seungyoup Chi 2006 Spitzer FLS : 12 out of 20 [< 1deg, 60%] with >2 mJy [rms ~333mJy] Wrobel et al. ApJ 2004 FIRST : 1.1mJy 71 + 14 out of 256 sources 28-33 % Porcas et al. 2004

10. results expected / observed 2 4.9 GHz flux / observed fraction / spec index 1.5 for Z > 2 ~15 GHz versus ~5 GHz source rest frame SBN

11. putting it together 3 16 12 9 21 19 5 15 X radio type optical I FRI / II X II [Martínez-Sansigre et al. sub 2006] 8 out of 11 Sources with EVN detection rate 73 % radio & infrared selection helps recover around 50% of flux within the inner 300 pc AGN feedback could switch off star formation would expect 4.3 type I quasars 3.8 deg2 8 - 11 type II 1:3 [hard X-ray] or 1:1

12. the future 10 -15 years from Jy to nJy SKADS Jarvis et al. In prep. 1deg2