1. An IRAM PdBI CO Survey of Luminous Submm Galaxies A spearhead project for ALMA IDA Meeting, Copenhagen 20-21 Dec. 2004 Thomas R. Greve (Caltech) R. Genzel (MPE), R. J. Ivison (ROE), R. Neri (IRAM), I. Smail (Durham), S. Chapman (Caltech), A. W. Blain (Caltech), F. Bertoldi (MPIfR), L. Tacconi (MPE), P. Cox (Orsay), A. Omont (AIP)

2. Outline  A Brief History of CO at high z  Why CO?  High-z CO detections to date  An interferometric CO survey of (sub)mm galaxies (SMGs)  Duty cycle and current status  Bulk gas properties of SMGs  Comparison with ULIRGs  Implications for galaxy formation models  Conclusions and future directions IDA Meeting, Copenhagen 20-21 Dec. 2004

3.  The symmetry of H 2 makes electric dipole transitions strictly forbidden and thus the cool H 2 gas is not directly observable.  We need tracer molecules to trace the cool gas (CO) A Brief History of CO at high z - Why CO? IDA Meeting, Copenhagen 20-21 Dec. 2004

4.  CO is powerful tool for probing molecular gas at high redshifts  Abundance  Strong rotational transitions  Rotational ladder, small rotational energy-spacing, which goes as 115GHz/(1+z)  CO has been studies in detail in GMCs in the Galaxy and in local starburst galaxies, e.g. (U)LIRGs A Brief History of CO at high z - Why CO? IDA Meeting, Copenhagen 20-21 Dec. 2004

5. High-z CO detections to date IDA Meeting, Copenhagen 20-21 Dec. 2004 13 QSOs, including IRAS F10214+4714 the first ever high-z CO detection (Brown & Vanden Bout 1991) 6 High-z Radio Galaxies (HzRGs) 1 Lyman Break Galaxy (LBGs)

6. High-z CO detections to date IDA Meeting, Copenhagen 20-21 Dec. 2004 Omont et al. (1996) z=4.69 13 QSOs, including IRAS F10214+4714 the first ever high-z CO detection (Brown & Vanden Bout 1991) 6 High-z Radio Galaxies (HzRGs) 1 Lyman Break Galaxy (LBGs)

7. High-z CO detections to date IDA Meeting, Copenhagen 20-21 Dec. 2004 De Breuck et al. (2003) z=3.52 13 QSOs, including IRAS F10214+4714 the first ever high-z CO detection (Brown & Vanden Bout 1991) 6 High-z Radio Galaxies (HzRGs) 1 Lyman Break Galaxy (LBGs) Omont et al. (1996) z=4.69

8. High-z CO detections to date IDA Meeting, Copenhagen 20-21 Dec. 2004 Baker et al. (2003) z=2.73 13 QSOs, including IRAS F10214+4714 the first ever high-z CO detection (Brown & Vanden Bout 1991) 6 High-z Radio Galaxies (HzRGs) 1 Lyman Break Galaxy (LBGs) De Breuck et al. (2003) z=3.52 Omont et al. (1996) z=4.69

9. High-z CO detections to date IDA Meeting, Copenhagen 20-21 Dec. 2004 Omont et al. (1996) De Breuck et al. (2003) Baker et al. (2003) 13 QSOs, including IRAS F10214+4714 the first ever high-z CO detection (Brown & Vanden Bout 1991) 6 High-z Radio Galaxies (HzRGs) 1 Lyman Break Galaxy QSOs+HzRGs show strong CO emission from extended (~10kpc) starburst regions Typical gas and dynamical masses of ~1x10 11 M o Co-eval growth of stellar bulges and massive black holes Rapid enrichment before z~7

10. High-z CO detections to date IDA Meeting, Copenhagen 20-21 Dec. 2004 Omont et al. (1996) De Breuck et al. (2003) Baker et al. (2003) 13 QSOs, including IRAS F10214+4714 the first ever high-z CO detection (Brown & Vanden Bout 1991) 6 High-z Radio Galaxies (HzRGs) 1 Lyman Break Galaxy QSOs+HzRGs show strong CO emission from extended (~10kpc) starburst regions Typical gas and dynamical masses of ~1x10 11 M o Co-eval growth of stellar bulges and massive black holes Rapid enrichment before z~7 However, most high-z CO detections are a mixed bag of non-uniformly selected (and often strongly lensed) QSOs and HzRGs

11. High-z CO detections to date IDA Meeting, Copenhagen 20-21 Dec. 2004 Omont et al. (1996) De Breuck et al. (2003) Baker et al. (2003) 13 QSOs, including IRAS F10214+4714 the first ever high-z CO detection (Brown & Vanden Bout 1991) 6 High-z Radio Galaxies (HzRGs) 1 Lyman Break Galaxy QSOs+HzRGs show strong CO emission from extended (~10kpc) starburst regions Typical gas and dynamical masses of ~1x10 11 M o Co-eval growth of stellar bulges and massive black holes Rapid enrichment before z~7 However, most high-z CO detections are a mixed bag of non-uniformly selected (and often strongly lensed) QSOs and HzRGs. SMGs: 2+1 sources detected in CO prior to our survey.

12. L1L2 R.A. (2000) Dec. (2000) SMMJ02399-0136 (z=2.81) 11 Ivison et al. 1998, MNRAS 298, 583 Frayer et al. 1998, ApJ, 506, L7 Genzel et al. 2003, ApJ, 584, 633 M dyn (R<8kpc) ~ 2-3x10 11 M O Most of which is baryonic IDA Meeting, Copenhagen 20-21 Dec. 2004

13. SMMJ14011+0252 (z=2.51) Ivison et al. 2001 ApJ 561, L45 Frayer et al. 1999, ApJ, 514, L13 Downes & Solomon 2003 ApJ 582, 37 IDA Meeting, Copenhagen 20-21 Dec. 2004

14. An IRAM PdBI CO Survey of SMGs (Genzel, Ivison, Neri, Bertoldi, Blain, Chapman, Cox, Greve, Neri, Omont, Smail, Tacconi) We are undertaking a first systematic CO survey of dust-enshrouded starburst galaxies at high redshifts Bright (S 850 >5mJy) submm-selected galaxies detected in the radio. This population is responsible for ~25% of the submm background. IDA Meeting, Copenhagen 20-21 Dec. 2004

15. Duty-cycle and current status: SCUBA/MAMBO sources with VLA 1.4GHz counterparts (Lockman E, ELAIS N2, SSA 22, SSA13, HDF-N etc). Keck follow-up spectroscopy with LRIS-B: ~70 redshifts, =2.4 We are undertaking a first systematic CO survey of dust-enshrouded starburst galaxies at high redshifts An IRAM PdBI CO Survey of SMGs (Genzel, Ivison, Neri, Bertoldi, Blain, Chapman, Cox, Greve, Neri, Omont, Smail, Tacconi) IDA Meeting, Copenhagen 20-21 Dec. 2004

16. Keck (LRIS-B + NIRSPEC) spectroscopy Chapman et al. (2003) Ivison et al. (2002) IDA Meeting, Copenhagen 20-21 Dec. 2004

17. Duty-cycle and current status: An IRAM PdBI CO Survey of SMGs SCUBA/MAMBO sources with VLA 1.4GHz counterparts (Lockman E, ELAIS N2, SSA 22, SSA13, HDF-N etc). Keck follow-up spectroscopy with LRIS-B: ~70 redshifts, =2.4 PdBI follow-up for redshift confirmation (2-3 tracks each) High-resolution PdBI follow-up for spatially resolved CO dynamics IDA Meeting, Copenhagen 20-21 Dec. 2004

18. Duty-cycle and current status: SCUBA/MAMBO sources with VLA 1.4GHz counterparts (Lockman E, ELAIS N2, SSA 22, SSA13, HDF-N etc). Keck follow-up spectroscopy with LRIS-B: ~70 redshifts, =2.4 PdBI follow-up for redshift confirmation (2-3 tracks each) High-resolution PdBI follow-up for spatially resolved CO dynamics Status winter 2004: 7 (+1) new CO detections, 6 non-detections - the number of SMGs detected in CO almost tripled! An IRAM PdBI CO Survey of SMGs IDA Meeting, Copenhagen 20-21 Dec. 2004

19. An IRAM PdBI CO Survey of SMGs First results Neri et al. (2003) z=2.509z=3.349 z=2.380 IDA Meeting, Copenhagen 20-21 Dec. 2004

20. An IRAM PdBI CO Survey of SMGs Greve et al. (2005) IDA Meeting, Copenhagen 20-21 Dec. 2004

21. An IRAM PdBI CO Survey of SMGs ID Transition z spec z CO FWHM I CO Our Detections km/s Jy km/s SMMJ02396-0134 (2-1)1.062+-0.0011.062+-0.002 780+-60 3.4+- 0.3 SMMJ13120+4242 (4-3)3.405+-0.0013.408+-0.002 530+-50 1.7+- 0.3 SMMJ16366+4105 (3-2) 2.454+-0.0012.450+-0.002 870+-80 1.8+- 0.3 SMMJ16371+4053 (3-2) 2.374+-0.001 2.380+-0.004 830+-130 1.0+- 0.2 SMMJ22174+0015 (3-2)3.098+-0.0023.099+-0.004780+-100 0.8+- 0.2 SMMJ04431+0210 (3-2) 2.5092+-0.0008 2.5094+-0.0002 350+-60 1.4+-0.2 SMMJ09431+4700 (4-3) 3.349+-0.001 3.3460+-0.0001 420+-50 1.1+-0.1 SMMJ16368+4057 (3-2) 2.380+-0.002 2.3853+-0.0014 840+-110 2.3+-0.2 (7-6)... 2.383+-0.002... 1.1+- 0.2 Non-detections SMMJ10523+5722 (3-2) 2.611+-0.001 2.5901 - 2.6119... 1100 3.1+-0.4 SMMJ14011+0252 (3-2) 2.562+-0.002 2.5653+-0.0003 200+-40 2.4+-0.3 (3-2)... 2.5652+-0.0001 190+-11 2.8+-0.3 (7-6)... 2.5651+-0.0002 170+-30 3.2+-0.5 SMMJ16359+6612 (3-2) 2.5165+-0.0015 2.5168+-0.0003 500+-100 3.5+-0.1 (3-2)... 2.5174+-0.0002 500+-100 2.50+-0.12 EROJ16450+4626 (2-1) 1.443+-0.001 1.439+-0.001 400+-20 1.40+-0.10 (5-4)... 1.440+-0.001 380+-20 1.35+-0.10 (1-0)......... 0.6+-0.1

22. IDA Meeting, Copenhagen 20-21 Dec. 2004 Greve et al. (2005) Genzel et al. (2003) Neri et al. (2003) Downes & Solomon (2003) An IRAM PdBI CO Survey of SMGs Neri et al. (2003)Greve et al. (2005) z=1.062z=2.803 z=2.562z=3.405z=3.349 z=2.509

23. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs Neri et al. (2003)Kneib et al. (2004)Greve et al. (2005) Andreani et al. (2000)Greve et al. (2005) z=2.380z=2.517z=2.454 z=3.098z=1.439z=3.098

24. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs  7 (+1) out of 13 (+1): detection rate of 54-57%. Remarkably good - comparable to the radio-ID fraction.  This confirms the =2.4 redshift distribution of the bright, radio-detected SMG population (Chapman et al. 2003).

25. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs  7 (+1) out of 13 (+1): detection rate of 53-57%. Remarkably good - comparable to the radio-ID fraction.  This confirms the =2.3 redshift distribution of the bright, radio-detected SMG population (Chapman et al. 2003). Greve et al. (2005)

26. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs  7 (+1) out of 13 (+1): detection rate of 54-57%. Remarkably good - comparable to the radio-ID fraction.  This confirms the =2.4 redshift distribution of the bright, radio-detected SMG population (Chapman et al. 2003).  H  provides much more reliable estimate of the systemic (CO) redshift:  V(CO-Ly  )  V(CO-H  ) blueshifted: 5 0 redshifted : 2 0 zero offset : 1 4

27. IDA Meeting, Copenhagen 20-21 Dec. 2004 Greve et al. (2005) An IRAM PdBI CO Survey of SMGs Bulk gas properties: CO luminosity: =(3.8+-2.0)x10 10 K km/s 4x ULIRGs Gas masses (including HI+He): =(3.0+-1.6)x10 10 M O 4x ULIRGs So SMGs contains 3-4x more gas than local ULIRGs. Depletion of Gas as the merger progresses (Gao et al. 1999)? Detection rate: z>2.4 : 5/7 (71%) z<2.4 : 2/6 (33%) Is this evidence for evolution in gas mass content?

28. IDA Meeting, Copenhagen 20-21 Dec. 2004 Starformation efficiency: SMGs extend the (non-linear) FIR-CO correlation to higher z and luminosities SMGs: =(450+-170) L O M O -1 ULIRGs: =(180+-130) L O M O -1 Starformation efficiency might be higher in SMGs than in ULIRGs Tentative evidence of a FIR- CO correlation within the SMG sample itself An IRAM PdBI CO Survey of SMGs log(LCO) = 0.6 log(LFIR) + 2.4 Greve et al. (2005)

29. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs Starformation efficiency: SMGs extend the (non-linear) FIR-CO correlation to higher z and luminosities SMGs: =(450+-170) L O M O -1 ULIRGs: =(180+-130) L O M O -1 Starformation efficiency might be higher in SMGs than in ULIRGs Tentative evidence of a FIR- CO correlation within the SMG sample itself Greve et al. (2005)

30. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs Dynamical masses: The double horn profiles are indicative of ordered orbital motion: either circum-nuclear disk or a merger. Assuming: 1) a conservative source size of D=0.5” (~3.7kpc at z=2.3) 2) random orbital inclinations (factor of  /4) 3) Merger model* SMG = (1.2+-1.5) x 10 11 M O * Toomre stability criterion: Q =  v s  G  1 for a gaseous disk to be stable. We find Q << 1 for M gas =3x10 10 M O and R~4kpc.

31. IDA Meeting, Copenhagen 20-21 Dec. 2004 Greve e al. (2005) An IRAM PdBI CO Survey of SMGs Dynamical masses: Velocity dispersion of SMGs is comparable to that of HzRGs and 3-4x that of ULIRGs. Assuming M dyn ~ R  2, and ULIRGs: M dyn (R<0.6kpc) ~ 6x10 9 M O, we find SMGs: M dyn (R<0.6kpc) ~ 4x10 10 M O The large line widths of SMGs strongly suggest that they are massive systems - with M dyn comparable to HzRGs.

32. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs Gas mass fractions: Gas fraction: SMGs : M gas /M dyn ~ 0.3 ULIRGs: ~ 0.16 (Downes & Solomon 1998) So SMGs appear to be more gas-rich than local ULIRGs, although this is subject to uncertainties in the CO-H 2 conversion factor and dynamical mass estimates. But overall there is mounting evidence that SMGs are neither high-z replicas of local ULIRGs, nor simply scaled up versions. Rather SMGs are more gas-rich and seem to form stars more efficiently (caveat: CO doesn’t trace the dense starforming gas, HCN does!)

33. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs Gas consumption time-scale and baryonic masses: The median starformation rate is =720 M O yr -1, hence the duration of the ‘SCUBA/MAMBO’-phase is:  = M(H 2 )/SFR ~ 40Myr This is a lower limit since it assumes continuous starformation and ignores negative feedback and the possibility of HI falling in from outer regions.

34. IDA Meeting, Copenhagen 20-21 Dec. 2004 An IRAM PdBI CO Survey of SMGs Gas consumption time-scale and baryonic masses: The median starformation rate is =720 M O yr -1, hence the duration of the ‘SCUBA/MAMBO’-phase is:  = M(H 2 )/SFR ~ 40Myr This is a lower limit since it assumes continuous starformation and ignores negative feedback and the possibility of HI falling in from outer regions. The median V-band restframe luminosity is 2 x 10 11 L O, which implies median stellar mass of M * ~ 3 x 10 10 M O (Smail et al. 2004). So the typical baryonic mass is M bar ~ 6 x 10 10 M O - comparable to the masses of local L* galaxies. And SMGs are baryon-dominated in their inner regions: M bar /M dyn ~ 0.5. Assembling that much baryonic matter so early is a severe challenge for models!

35. IDA Meeting, Copenhagen 20-21 Dec. 2004 Implications for Models of Galaxy Formation Greve et al. (2005) A fundamental test-bed for galaxy formation models is the assembly of massive baryonic galaxies. Co-moving number density of M bar = 6 x 10 10 M O is n(M>M bar ) ~ 5 x 10 -6 Mpc -3 Corrected for our CO detection Fraction (0.53) and finite survey volume.

36. IDA Meeting, Copenhagen 20-21 Dec. 2004 Implications for Models of Galaxy Formation A fundamental test-bed for galaxy formation models is the assembly of massive baryonic galaxies. Co-moving number density of M bar = 6 x 10 10 M O is n(M>M bar ) ~ 5 x 10 -6 Mpc -3 Corrected for our CO detection Fraction (0.53) and finite survey volume. This is a lower limit since we must correct for the finite life time of SMGs:  (2.0-3.5)/  SMG = 1.5Gyr/(40-200)Myr = 8-38 10 11 Mo 7x10 10 Mo 5x10 10 Mo Greve et al. (2005)

37. High-resolution PdBI observations of SMGs - a taste of ALMA IDA Meeting, Copenhagen 20-21 Dec. 2004 Tacconi et al. in prep. 1.3mm continuum, beam 0.7”x0.6” SMMJ09431+4700: H6 + H7 (both radio sources) are part of the same physical structure - separation 22kpc

38. IDA Meeting, Copenhagen 20-21 Dec. 2004 Tacconi et al. in prep. SMMJ09431+4700: CO(4-3) is detected in H7 (but not H6). Tentative evidence for a blueshifted filament of gas between H7+H6. High-resolution PdBI observations of SMGs - a taste of ALMA

39. IDA Meeting, Copenhagen 20-21 Dec. 2004 Tacconi et al. in prep. SMMJ09431+4700: CO(4-3) is detected in H7 (but not H6). Tentative evidence for a blueshifted filament of gas between H7+H6. We have ‘tasted’ what we might expect to achieve with ALMA! High-resolution PdBI observations of SMGs - a taste of ALMA

40. IDA Meeting, Copenhagen 20-21 Dec. 2004 Tacconi et al. in prep. SMMJ163681+4057: High-resolution PdBI observations of SMGs - a taste of ALMA

41. The Future… IDA Meeting, Copenhagen 20-21 Dec. 2004 CO is great! But… It doesn’t trace the dense starforming gas Need high-density tracers such as HCN Other molecular/atomic lines, e.g. CI Ultimate goal: detail ISM studies at high-z as well as ‘blind’ CO surveys. …is here and it’s interferometrical!

42. The Future… IDA Meeting, Copenhagen 20-21 Dec. 2004 …is here and it’s interferometrical! CO is great! But… It doesn’t trace the dense starforming gas Need high-density tracers such as HCN Other molecular/atomic lines, e.g. CI Ultimate goal: detail ISM studies at high-z as well as ‘blind’ CO surveys

43. IDA Meeting, Copenhagen 20-21 Dec. 2004 The Future…

44. IDA Meeting, Copenhagen 20-21 Dec. 2004 The Future… Courtesy Jesper Sommer Larsen