CO(1-0) survey of High-z Radio Galaxies: ATCA/CABB as crucial complement to ALMA Bjorn Emonts (CSIRO Astronomy & Space Science/ATNF) Ilana Feain (CASS), Minnie Mao (U. Tasmania), Ray Norris (CASS), George Miley (Leiden Obs.), Montse Villar-Martin (IAA Granada), Huub Rotggering (Leiden Obs.), Elaine Sadler (U. Sydney ), Ron Ekers (CASS) D.J. Saikia, T. Oosterloo, R. Morganti, G. Rees, E. Mahony, C. Carilli, G. van Moorsel, J. Stevens, M. WIerenga, A. Berciano, K. Coppin, K. Randall, C. Tadhunter

High-z Radio Galaxies (HzRG) Most massive galaxies in Early Universe Central proto-cluster galaxies (e.g. Venemans et al. 2007) anchestors of local rich cluster ellipticals Clumpy optical morphology (merging systems) (Pentericci et al. 2001) ; Radio jets vigorously interact with ISM (Humphrey et al. 2006) + alignments jets with UV/optical and CO (Chambers et al 1987; McCarthy et al. 1978; Klamer et al. 2004). Among best studied high-z objects Strong radio continuum beacon for tracing faint host galaxy/proto-cluster; Optical quasar-core generally shielded by torus 4C41.17 (z = 3.8) (Reuland et al. 2003) Lyα (warm ionised gas) Radio cont.  Holistic approach! To fully understand HzRGs:

Molecular gas in HzRG Molecular gas: raw ingredient for star formation H 2 virtually invisible CO strong tracer (rotational transitions): CO(1-0) [115 GHz], CO(2-1) [230 GHz], CO(3-2) [345 GHz], CO(4-3) [460 GHz], etc. 1991: First observations of CO at z > 2 (Brown & Vanden Bout 1991) CO as tracer for molecular gas in HzRGs: First (single-dish) surveys failed to detect CO (Evans et al 1996, van Ojik et al 1997) Since then, CO detected in individual HzRG (Miley & De Breuck 2008; also Scoville et al. 1997, Papadopoulos et al. 2000, 2001, Alloin et al. 2000, De Breuck et al. 2003a,b, 2005, Greve et al. 2004, Klamer et al. 2005, Ivison et al. 200,; Nesvadba et al. 2009) CO can be resolved on scales of tens of kpc (e.g. Papadopoulos et al. 2000) Reuland et al. (2003); Carilli et al (1997) 4C41.17 (z = 3.8) De Breuck et al. (2005)

CO studies of HzRG

ATCA/CABB: upgraded in 2009 ATCA Compact Array Broadband Backend (CABB) has overcome these limitations: 4 (2x2) GHz bandwidth, 1 MHz res. Observing frequencies < 50 GHz 3mm ( GHz); 7mm (30-50 GHz); 15mm (16-25 GHz) Hybrid array configurations with baselines as short as 31m. e.g. at f obf = 40 GHz (7mm band) Δv ~15,000 km/s per 2 GHz! Australia Telescope Compact Array (Narrabri, NSW) H75 hybrid array Similar to EVLA/WIDAR in the northern hemisphere down to dec -25 o (elevation +30 o for mm work)

ATCA/CABB: upgraded in 2009 ATCA’s Compact Array Broadband Backend (CABB) has overcome these limitations: 4 (2x2) GHz instantaneous bandwidth Observing frequencies < 50 GHz 3mm ( GHz ); 7mm (30-50 GHz ); 15mm (16-25 GHz ) Hybrid array configurations Coppin et al. (2011): First detection of high-z CO with ATCA/CABB: CO(2-1) in submm-galaxy at z=4.8 !! M H2 = 1.6 x M sun (α [M H2 /L CO ] = 0.8) SMG (z=4.8) LESS J

CO(1-0) survey of HzRG with ATCA/CABB CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Status: - 6 sources observed (t int ~15h per source) - 5 sources scheduled in Aug/Sept First systematic survey of CO(1-0) in unbiased sample of HzRGs. Sample selection: All HzRGs from MRC catalogue (unbiased in IR, submm, etc): - observable in ATCA 7mm band (1.5 < z < 3) - dec < HST imaging & Spitzer data available 14 sources

CO(1-0) survey of HzRG with ATCA/CABB Pilot study: Performance of ATCA/CABB MRC (z = 2.5); f obs = 33 GHz (optimum CABB freq.) Upper limit M H2 < 2 x M sun (α[M H2 /L CO ]= 0.8) pre-CABB CABB! Emonts et al. 2011, MNRAS, in press. (arXiv/ ) 0.1, 0.3, 1.0, 1.7, 2.4mJy/bm t int = 19.5h σ line = 0.45 mJy/bm/ch 1MHz σ cont = 0.29 μJy/bm radio cont.

CO(1-0) survey of HzRG with ATCA/CABB Pilot study: Performance of ATCA/CABB MRC (z = 2.9) – very edge of 7mm band Tentative off-nuclear detection (M H2 = 6 x M sun ; α[M H2 /L CO ]= 0.8 ) CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Emonts et al. 2011, MNRAS, in press. (arXiv/ ) 0.4, 1.0, 2.0, 3.0 mJy/bm radio cont. t int = 19h

CO(1-0) survey of HzRG with ATCA/CABB CO(1-0) in z=1.92 radio galaxy MRC Most significant (S/N) CO(1-0) detection in HzRG to date! Only two other known CO(1-0) detections in HzRG Emonts et al. (2011), ApJL accepted (arXiv/ ) CSIRO. ATCA/CABB CO(1-0) survey of HzRGs M H2 = 6 x M s (α[M H2 /L CO ]= 0.8) Δv = 400 km/s ATCA/CABB Pentericci et al. (2000, 2001) z opt

CO(1-0) survey of HzRG with ATCA/CABB CO(1-0) in z=1.92 radio galaxy MRC Emonts et al. (2011), ApJL accepted (arXiv/…..) CSIRO. ATCA/CABB CO(1-0) survey of HzRGs M H2 = 6 x M s (α[M H2 /L CO ]= 0.8) Δv = 400 km/s ATCA/CABB Pentericci et al. (2000, 2001) Feain et al. (2005) ATCA pre-CABB TN J0924–2201 (z =5.2) M H2 ~ M s Most significant (S/N) CO(1-0) detection in HzRG to date! Only two other known CO(1-0) detections in HzRG

CO(1-0) survey of HzRG with ATCA/CABB CO(1-0) in z=1.92 radio galaxy MRC Emonts et al. (2011), ApJL accepted (arXiv/ ) CSIRO. ATCA/CABB CO(1-0) survey of HzRGs M H2 = 6 x M s (α[M H2 /L CO ]= 0.8) Δv = 400 km/s ATCA/CABB Pentericci et al. (2000, 2001) MRC contains large amounts of molecular gas that has not yet been depleted by star formation or radio-AGN feedback. 83 kpc 8 kpc

CO(1-0) survey of HzRG with ATCA/CABB CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Status (14 sample sources):: - 6 sources observed (t int ~15h per source) 1 detection 1 tentative detection - 5 sources scheduled in Aug/Sept First systematic survey of CO(1-0) in unbiased sample of HzRGs.

CO(1-0) survey of HzRG with ATCA/CABB CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Status (14 sample sources):: - 6 sources observed (t int ~15h per source) 1 detection 1 tentative detection - 5 sources scheduled in Aug/Sept First systematic survey of CO(1-0) in unbiased sample of HzRGs. Compar Compare with ongoing EVLA CO(1-0) surveys: - high-z submm galaxies (Ivison et al. 2011) - high-z starforming BzK galaxies (Aravena et al. 2010) CO(1-0) only detected in compact radio sources, or outside the radio continuum (but low number statistics!) - CO(1-0) – molecular gas least affected by excitation/heating – at radii not affected by radio source?? - Alignment CO(1-0) with radio jets? (e.g. Klamer et al 2004)

ALMA Early-Science (cycle-0) Riechers et al. (2011) CO excitation ladder Peak S ν : 0.8 mJy/bm CSIRO. ATCA/CABB CO(1-0) survey of HzRGs CO(6-5) in radio galaxy MRC CO(6-5): f obs = 236 GHz (ALMA band 6) Dense molecular gas in starburst/AGN region 0.7” resolution (comparable to HST morphology) Physical properties (density/temp) excitation ladder: CO(1-0) (ATCA) + CO(6-5) (ALMA) Quasars SMG CO(1-0) CO(6-5) 400 km/s

ALMA Early-Science CO(6-5) in radio galaxy MRC Dense molecular gas in starburst/AGN region Riechers et al. (2011) CO excitation ladder 0.8 mJy/bm Compar ALMA cycle-0: t int = 1h (on-source) f obs = 236 GHz (band 6) Δv = 50 km/s σ = 0.6 mJy/bm CO(1-0) (6-5) x10-30! CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Quasars SMG CO(6-5) integrated signal at σ level Extended array – 0.7” res. (compact array ”) Resolve CO(6-5) signal kinematically and spatially at ~6 kpc (19 kpc)

ALMA Early-Science CO(6-5) in radio galaxy MRC Dense molecular gas in starburst/AGN region Riechers et al. (2011) CO excitation ladder 0.8 mJy/bm Compar ALMA cycle-0: t int = 1h (on-source) f obs = 236 GHz (band 6) Δv = 50 km/s σ = 0.6 mJy/bm CO(1-0) (6-5) x10-30! CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Quasars SMG CO(6-5) integrated signal at σ level Extended array – 0.7” res. (compact array ”) Resolve CO(6-5) signal kinematically and spatially at ~6 kpc (19 kpc) 15σ

CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Conclusions ATCA/CABB crucial southern instrument for complementary studies of high-z CO with ALMA CO(1-0) observations with ATCA/CABB: most robust tracer for molecular gas at high-z (incl low-density, widespread, sub- thermally excited component). ATCA/CABB excellent mm spectral-line performance Ongoing systematic survey of CO(1-0) in HzRG MRC : strongest CO(1-0) signal in HzRG to date Ideal for ALMA observations of high CO transitions of dense molecular gas

ATCA/CABB ATCA/CABB has overcome these limitations: 4 (2x2) GHz instantaneous bandwidth Observing frequencies < 50 GHz 3mm ( GHz); 7mm (30-50 GHz); 15mm (16-25 GHz) Hybrid array configurations with baselines as short as 31m. Example: CO(2-1) at z=5 f obf = 38 GHz (7mm band) Δv=15,000 km/s per 2 GHz! Similar for EVLA/WIDAR in the northern hemisphere EVLA 27 vs ATCA 5/6 dishes; ATCA H75: 15 baselines <100m EVLA D-array: 41 baselines <100m (12% of all baselines) EVLA ‘E-array’ would be fantastic! EVLA mm-observations only down to dec ~ -25 deg H75 hybrid array (ATCA - Narrabri, NSW) CSIRO. ATCA/CABB CO(1-0) survey of HzRGs

CO(1-0) survey of HzRG with ATCA/CABB CO(1-0) in z=1.92 radio galaxy MRC Pentericci et al. (2000, 2001) CSIRO. ATCA/CABB CO(1-0) survey of HzRGs Emonts et al. (2011), ApJL accepted (arXiv/…..) 83 kpc 8 kpc

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