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The Hunt for Molecules at High Redshift. Pierre Cox IRAM Grenoble, France. History of the Universe. Recombination (z~1000). Cosmic ‘Dark Ages’ - no stars/quasars. Epoch of re-ionization (6<z<20). Peak of activity QSOs & submm galaxies (z~2.5). mass buildup. Galaxies today.
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The Hunt for Molecules at High Redshift Pierre Cox IRAM Grenoble, France The Hunt for Molecules IAP, Paris
History of the Universe Recombination (z~1000) Cosmic ‘Dark Ages’ - no stars/quasars Epoch of re-ionization (6<z<20) Peak of activity QSOs & submm galaxies (z~2.5) mass buildup Galaxies today The Hunt for Molecules IAP, Paris
High Redshift Galaxies • high redshift zoo: • - Lyman Break galaxies • - Lyman a galaxies • - Submm (‘SCUBA’) galaxies • - EROs • - DRG • - BzK galaxies • - faint blue galaxies • - Radio galaxies • - QSO host galaxies • science drivers: • - mass assembly / galaxy formation • - unified picture of galaxy evolution • - history of Star Formation • / stellar mass assembly • - evolution(?) of MBH-s relation mm/submm observations: - detection/imaging of dust emission -> LFIR - detection/imaging of molecular lines -> molecular gas (‘SF reservoir’) -> dynamical masses major science drivers for all (sub)mm instruments The Hunt for Molecules IAP, Paris
Amplification Inverse K-correction A 1835 The Hunt for Molecules IAP, Paris
Deep Field Sources 15”/10” SCUBA/ MAMBO Source identification critical (usually through RC, Chapman et al. 2004) Pointed Observations - Sources selected from optical (SDSS) and radio (VLA): Quasars, radio-galaxies - Position well known; redshifts known The Hunt for Molecules IAP, Paris -> poster
Tdust = 52 K Beta = 1.5 L_FIR = 4x1012 x S250(mJy) L_sun for z=0.5 to 8 SFR = 1400 x S250(mJy)M_sun/yr (very high) M_dust = 1.4x108 x S250(mJy) M_sun Beelen et al. 2005 The Hunt for Molecules IAP, Paris
Molecular Gas • Detection of dust • Molecular gas: fuel for Star Formation • Cold H2 invisible Use CO as tracer • Molecular gas mass, Dynamical mass • n[CO(n-(n-1))] = (115GHz x n) / (1+z) z=6 CO(1-0): 3mm 2cm ! • so far 2 major populations: - submm galaxies - QSO host galaxies [but also radio gal, LBG….] • Problem: accurate z not known - faint in optical (submm gal.) - complex emission lines (QSO hosts) M82 The Hunt for Molecules IAP, Paris
Among the first detections of CO at high redshift Cloverleaf at z=2.6 BR1202-0725 at z=4.12 The Hunt for Molecules IAP, Paris
The Hunt for Molecules IAP, Paris
The Lfir vs Lco relation The Hunt for Molecules IAP, Paris
CO Survey of submm Galaxies • 11 radio-detected submm galaxies with known optical/near-IR redshift detected in CO • 1<z<3.5 • Variety of profiles: 780+-230 km/s • Mergers/Rotating Disks • Star Formation Rate: 720 Msun/yr • MH2~ 3x1010 Msun • Mdyn ~ 1011 Msun • The submm-population consists of gas rich and massive, composite starbursts/AGN systems, which are going a major burst of star formation (i.e. 108 yr) and evolving in m*-galaxies SMM J02396-0134 SMM J02399-0136 SMM J04431+0210 SMM J09431+4700 SMM J13120+4242 SMM J14011+0252 SMM J16368+4057 SMM J16359+6612 SMM J16366+4105 (Greve et al. 2005; Neri et al. 2004) The Hunt for Molecules IAP, Paris SMM J16371+4053 ERO J16450+4626 SMM J22174+0015
CO toward the z=2.5 galaxy SMM J16359+6612. CO(3-2) mag=45 Kneib, Neri, Smail et al. A&A, 2005 The Hunt for Molecules IAP, Paris
Gunn Peterson trough J1148+5251 - The Most Distant QSO at z=6.42 Fan et al. 2003; White et al. 2003 z-band (Keck – Djorgovski et al.) • z=6.42; age~870 Myr • one of the first luminous sources • MBH ~ 1-5 x 109 Msun (Willot et al. 2003) • Mdust ~ 108 Msun(Bertoldi et al. 2003) Dust continuum at 1.2 mm The Hunt for Molecules IAP, Paris
CO(3-2) 46.6149 GHz PdBI continuum VLA Walter et al. 2003 Bertoldi et al. 2003 The Hunt for Molecules IAP, Paris
Mass: • MH2 = 2 x 1010 Msun • Mdyn = 3 x 109 sin-2(i) Msun • Mass in C and O: ~3x107 Msun CO excitation in J1148+5251 (filled circles), compared to NGC 253 (dashed) LVG Model: Tkin= 100K, nH2=7x104 cm-3 Bertoldi et al. (2003) The Hunt for Molecules IAP, Paris
Resolving the CO emission in J1148+5251 VLA A+B + C array; res.: 0.15” (~1 kpc) • Two sources separated by 0.3” (1.7 kpc at z=6.4) containing each 5 x 109 Msun • Not likely to be amplified • If gravitationally bound, MDyn=4.5x1010 Msun Walter et al. 2004 The Hunt for Molecules IAP, Paris
Multiple CO Lines: Gas Excitation f(T) f(r) Multiple components 4.2 140 K 3.4 40 K 20 K 3.0 • Turnover: measure of the CO excitation • Shape is temperature/density dependent • Shape: search for extended CO LVG Input: n(H2), Tkin, [CO]/[H2]/dv/dr (fixed to 810-5 pc (km/s)-1) The Hunt for Molecules IAP, Paris Weiss 2005
Multiple CO Lines IRAM 30m CO multiline survey (1, 2, 3mm bands) The Hunt for Molecules IAP, Paris
LVG solution Cloverleaf Tex (CI) ~ low J Tex (CO) [similar critical densities] CO LVG solution: Disk radius: 1 kpc excellent agreement with lens models ! log(n(H2)) = 4.2 cm-3 Tkin = 30 K M(H2) = 8 1010 M L’CO(1-0) = 4.4 1010 K km/s pc2 Xco = 1.8 M/ K km/s pc2 Neutral Carbon: M(CI) = 3 107 M [CI]/[H2] = 6 10 –5 (~4 10-5 local starbursts)
Antennae M51 Arp220 Mrk 231 rCO ~200 pc rCO ~ 4kpc rCO ~ 500 pc rCO ~ 1.5kpc CO Line Energy Distribution Local starbursts: Tkin ~ 50 K, n(H2) ~ 10 4.0cm-3 Merger of two spirals (r~ 4 kpc) if central gas concentration as in ULIRGs (200 pc), average molecular density rises by >2 orders of magnitudes The Hunt for Molecules IAP, Paris
High Density Tracer: HCN J1409+5628 (z=2.56) High density tracer in starbursts: nH2> 10(5) cm(-3) APM08279+5255 APM08279+5255 (z=3.91) Gao & Solomon 2004 Carilli et al. 2004 Wagg et al. 2005 The Hunt for Molecules IAP, Paris
Tentative detection of CH+ in the Cloverleaf E. Falgarone et al. (2005) The Hunt for Molecules IAP, Paris
Search for Neutral Carbon [CI] Cloverleaf (z=2.3) F10214 (z=2.3) SMM 14011 (z=2.5) CI ( 3P2-3P1 ) PdBI CI ( 3P1-3P0 ) 30m CI ( 3P1-3P0 ) 30m CI ( 3P1-3P0 ) 30m 2nd extra galactic CIratio L’CI(21) / L’CI(10)= 0.5, Tex = 30 K [CI]/H2 ~ 3 x 10(-5) PSS2322 (z=4.12) CI ( 3P1-3P0 ) PdBI Barvainis et al. 1997; Weiss et al. 2003, 2004; Pety et al. 2004 The Hunt for Molecules IAP, Paris
[[CII] 158 microns emission line detected in J1148+5251 at z=6.42Probing the physics of a PDR at the end of the re-ionisation epoch CO(7-6) CII CI(1-0) The Hunt for Molecules IAP, Paris
[CII] in J1148+5251 • Done at the 30-meter • Massive starburst (2000 Msun/yr) • Significant metal enrichment • The ratio of the [CII] line luminosity to the total far-infrared luminosity is about 0.06%, i.e. an order of magnitude smaller than has been observed locally • One of the 3 key scientific goals of the ALMA project. Maiolino, Cox et al. (2005) The Hunt for Molecules IAP, Paris
Conclusions • From ‘blobology’ to physics and (chemistry) of the ISM in the early Universe • CO measurements physical conditions of the dense, warm gas in star-forming galaxies at high redshifts: massive (1010 M), compact (~ 1kpc), dense (104 cm-3) and enriched (abundances ~ solar) • High temperature (40-100 K) and densities (104 cm-3) comparable to local ULIRGs, though scaled-up versions. • Detection of species other than CO: HCN, [CI] and [CII] • Some sources have been resolved with 1 kpc (~0.2”) • Studies in the very early universe (< 1 Gyr): • - Metal enrichment • - Dynamical masses • SO FAR ONLY TIP OF THE ICEBERG The Hunt for Molecules IAP, Paris
Herschel/Planck Spitzer Space Telescope Early ALMA Science APEX LMT CARMA ALMA 50 JCMT CSO SMA Plateau de Bure 30-meter The Hunt for Molecules IAP, Paris 2004 2006 2008 2010 2012 2014
‘PdBI-2006’ • New generation broadband receivers • Frequency coverage: 80-117, 125-180, 200-260 & 260-349 GHz • Two polarizations • 4 GHz instantaneous bandwidth • Improved Sensitivity: ~2 for Spectroscopy and ~5 in Continuum as compared to the current system • Improved Frequency Coverage Extension of the baselines: • NS (368 m) & EW (800 m) • HPBW of 0.3 arcsec at 230 GHz IF processing and transport (optical fibers) & New Correlator The Hunt for Molecules IAP, Paris