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A New Era of Molecular Line Studies in Early Universe Galaxies: Prospects of the (E)VLA

A New Era of Molecular Line Studies in Early Universe Galaxies: Prospects of the (E)VLA. The EVLA Vision: Galaxies Through Cosmic Time DSOC, Socorro, NM December 16-18, 2008 Dominik A. Riechers California Institute of Technology. Hubble Fellowship HST-HF-01212.01-A.

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A New Era of Molecular Line Studies in Early Universe Galaxies: Prospects of the (E)VLA

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  1. A New Era of Molecular Line Studies in Early Universe Galaxies: Prospects of the (E)VLA The EVLA Vision: Galaxies Through Cosmic Time DSOC, Socorro, NM December 16-18, 2008 Dominik A. Riechers California Institute of Technology Hubble Fellowship HST-HF-01212.01-A F. Walter (MPIA), C. Carilli (NRAO), F. Bertoldi (AIfA), A. Weiss (MPIfR), P. Cox, R. Neri (IRAM), G. Lewis, B. Brewer (U Sydney), J. Wagg (NRAO), R. Wang (U Peking), C. Henkel (MPIfR), J. Kurk (MPIA), E. Daddi (CES), H. Dannerbauer (MPIA), N. Scoville (Caltech), M. Yun (UMASS), K. Menten (MPIfR), E. Momjian (NRAO), M. Aravena (AIfA)

  2. The role of Quasars (QSOs) • Most galaxies in the universe have a central black hole • QSOs: • high accretion events • special phase in galaxy evolution • most luminous sources in universe black hole mass e.g., Häring & Rix 2004 • Origin of ‘Magorrian relation’ at z=0 ? • Mstars~700 MBH • [masses are correlated on size scales • spanning 9 orders of magnitude!] stellar mass Question: do black holes and stars grow together? currently favored theories: yes (=> common, growth-limiting mechanism, ‘feedback’) complication: bright! Ideally, want to study mass compositions as f(z)

  3. …going to highest redshifts Z = 1000 Earliest epoch sources: longest ‘time baselines’ critical redshifts/timescales: - z=4-6.4 (highest z QSO) corresponds to: - 0.8-2 Gyr after Big Bang z = 15 z = 6 Basic measurements: MBH black hole Mbulge stars Mgas gas (& dust) Mdyn dynamical mass Credit: Caltech Media EVLA/ALMA z = 0

  4. Mgas: Molecular Gas at High z • molecular gas observations • at high-z help to constrain: • Mgas (fuel for SF & evol. state) • Mdyn(hierarchical models, M-) • ngas, Tkin(conditions for SF) • SFR (cosmic SF history) • evidence for mergers • (triggering of QSO activity & SF) ALMA EVLA Image courtesy: NRAO/AUI & ESO • detailed studies of molecular gas in the early universe: a main science goal for ALMA (see DSRP) • but: even ALMA (alone) will not be able to tell us the full story

  5. MBH black hole Mbulge stars Mgas gas Mdyn dynamical mass Resolving z>4 CO EmissionPaving the Road for EVLA & ALMA • molecular gas: >99% H2 – difficult to observe, use CO as tracer • ultimate goal: resolve CO emission spatially/kinematically • Dynamical masses, host galaxy sizes, disk galaxies vs. mergers • compare to AGN diagnostics: evolution (?) of MBH- relation critical scale: 1 kpc = 0.15” @z=4-6 • Only VLA can observe CO in z>4 QSOs at 0.15”/1 kpc resolution (B array @ 7mm) • We don’t need ALMA to achieve this! • Caveat: needs 50-80 hours per source • & the best weather conditions VLA 10 km baselines

  6. Resolving the Gas Reservoirs Perhaps best known example: J1148+5251 at z=6.42 J1148+5251 (z=6.4) Mdyn=MBH+Mstars+Mgas+Mdust (+MDM) opt./NIR spectroscopy [MgII, CIV] & Ledd dust SED L’CO • Mgas= 2 x 1010 M0 • Mdyn~ 6 x 1010 M0 • MBH = 3 x 109 M0 Mdyn ~ Mgas Mdyn = 20 MBH breakdown of relation seen at z=0? but: only one example/source 5 kpc reservoir Walter ea. 2004 DR ea. 2009 CO(7-6) IRAM PdBI

  7. HST ACS F814 PSS J2322+1944 (z=4.12):A Molecular Einstein Ring Lensed CO(2-1) VLA - 70h VLA B/C array - 0.30” resolution • Molecular Einstein Ring • Optical: double image • Differentially lensed • Lensing helps to zoom in, but interpretation depends on lens model Image courtesy: NRAO/AUI DR ea. 2008a v=42 km/s CO velocity channel maps NRAO Press Release 2008 Oct 20

  8. Bayesian Reconstruction & Lens Inversion (Method: Brewer & Lewis 2006) A z=4.12 Molecular Einstein Ring Source Lens Data v=42 km/s CO velocity channel maps • CO emission spatially & dynamically desolved • Grav. Lens: Zoom-in: 0.30” -> 0.15” (1.0 kpc) Magnification:µL=5.3 (CO) & 4.7 (AGN) • 5 kpc reservoir, AGN not central: likely interacting • Mgas=1.7 x 1010Mo Mdyn=4.4 x 1010 sin-2i Mo • MBH=1.5 x 109Mo Mdyn/MBH=30 CO(2-1) DR ea. 2008a 8.5 kpc

  9. BRI 1335-0417 (z=4.41):Interacting Galaxy CO(2-1) in BRI 1335-0417 (z=4.41) Not Lensed CO(2-1) 50h VLA BC array 0.15”resolution (1.0 kpc @ z=4.4) • CO: 5 kpc diameter, vco=420 km/s 10 kpc • Mgas = 9.2 x 1010Mo • Mdyn = 1.0 x 1011 sin-2iMo • MBH = 6 x 109Mo (C IV) • Mdyn/MBH=20 spatially & dynamically resolved QSO host galaxy Dv=44 kms-1 CO channel maps (red to blue) DR ea. 2008b

  10. BRI 1335-0417 (z=4.41):A Major ‘Wet‘ Merger? CO(2-1) in BRI 1335-0417 (z=4.41) CO(1-0) in the Antennae (z=0) Both CO maps: 1.0 kpc resolution CO(1-0) on optical • Distant Quasar Host Galaxy: BRI 1335-0417 (z=4.41) • Mgas = 9.2 x 1010Mo, 5 kpc scale, SFR=4650 Moyr-1 • Nearby Major Merger: NGC4038/39 – the Antennae • Mgas = 2.4 x 109Mo, 7 kpc scale, SFR=50 Moyr-1 Wilson ea. 2000 • same scale, higher gas mass & SF efficiency in BRI1335 DR ea. 2008b

  11. Nearby Counterparts CO Imaging of PG QSOs at z=0.06 - 0.13 at 0.5”-0.7” (1 kpc) resolution PdBI • Imaged 5 sources with CARMA (320hr) & PdBI (20hr): • optical/FIR selection like high-z sources • MBH from reverberation mapping • 2-4 kpc scale CO reservoirs • some clear double sources/mergers • Mdyn/MBH= 250 – 700 • => comparable to optical M* estimates (vel. disp.) • => compatible with z=0 MBH-Mbulge relation CARMA DR ea. in prep.

  12. Mdyn and the High-z MBH-Mbulge Relation APM08279+5255 (z=3.91) B1335-0417 (z=4.41) J1148+5251 (z=6.42) J2322+1944 (z=4.12) Now: 4 sources at z>4 studied in detail In all cases: Mgas ~ Mdyn Mdyn ~ 20-30 MBH [cf. 700 MBH] • no room for massive stellar body within central ~5kpc • Did black holes form first in these objects (z-evolution of MBH-Mbulge)? - Does MBH-Mbulge change toward high-mass end? Bulge buildup through SF & mergers takes time PG 1351+640 (z=0.088) PG 1426+015 (z=0.086) PG 1613+658 (z=0.129) PG 2130+099 (z=0.063) PG 1440+356 (z=0.079) z=0 Haering & Rix 2004 DR ea., in prep. • Need improved theoretical framework for • interpretation (Desika Narayanan’s Talk)

  13. Moving towards the EVLA & ALMA era Really want to go beyond z>7 to probe into the Epoch of Reionization earliest structures in universe sources that contributed to reionization Are CO observations w/ ALMA the answer?

  14. CO Excitation in High-z Sources Observed CO Line Excitation CO at J>8 not highly excited! high z low z Low-excitation: Also z=1.5 BzKs Milky Way Daddi ea. 2008 Dannerbauer ea. 2009 => Emanuele Daddi’s Talk Weiss ea., in prep.

  15. Freq. of [CII] CO NOT EXCITED CO discovery space almost an ‘EVLA exclusive’ area EoR Sources: CO discovery space EoR BzKs DR 2007, PhD thesis Walter, Weiss, DR ea. 2008

  16. CO, FIR continuum, and Ionized Carbon at z=6.42 0.32”x0.23” res. VLA PdBI CO FIR continuum J1148+5251 (z=6.4) [CII] [CII] (ionized carbon): major cooling line of the ISM 2P3/2 - 2P1/2 fine-structure line --PDR / SF tracer Rest frequency: 1900 GHz (158 microns) ISO observations: [CII] carries high fraction of LFIR, much brighter than CO • Same dynamical width, but CO & [CII] not 100% aligned • [CII] traces 1.5 kpc SF region within 5 kpc molecular reservoir • with SFR surface density of ~1000 M0 yr-1 kpc-2 (Edd. limited) Walter ea. 2004 Walter, DR ea. 2008 DR ea. 2009 Need both [CII] with ALMA & CO with the EVLA

  17. Summary • ‘mass budget’ of QSOs out to z=6.4 (multi-) • MBH, Mgas, Mdyn can be measured • density, temperature, dynamical structure of gas reservoirs • 4 objects at z~4-6: Mdyn ~ Mgas Mdyn ~ 20-30 MBH [vs. ~700 today] • evolution with redshift or change toward high-mass end? • black holes in QSOs may form before bulk of stellar body • theories need to account for this (=> Desika Narayanan’s Talk) • demonstrated: • [CII] will be key diagnostic line for z>7 Universe for ALMA • but: complementing observations of CO with EVLA essential • now: tip of the iceberg: ‘new’ IRAM PdBI, and soon EVLA & ALMA: bright future for dark ages

  18. EVLA: spectral resolution, n-coverage and bandwidth VLA Multiple lines per observing setup CO @z=6.4, VLA 3 separate observing setups 250 MHz total, 50 MHz resolution z=3.9 Walter ea. 2003 High spectral resolution DR ea. 2006a HCO+(1-0) VLA Tracers of dense, SF gas Detected @ high z: HCN, HCO+, CS, CN, HNC CO @z=4.7, GBT => Yu Gao’s Talk Multiple CO isotopomers: Direct Estimates of Mgas z=2.6 Initial detections: Barvainis ea. 1997, Solomon ea. 2003, DR ea. 2006b, 2007, 2009, Guelin ea. 2007, Henkel ea., i.p.

  19. EVLA: Prospects • Potential EVLA-exclusive Key Projects in the field of high-z molecular line studies: • Detect and image CO emission in z>7 galaxies (plus [CII]/FIR maps w/ ALMA) • => spatially resolved Schmidt star formation law out to the first galaxies • => dynamical masses to constrain high-z M-srelation • => gas masses to determine starburst lifetimes/galaxy evolutionary states • Image z=1.5-3 star-forming galaxies with Milky Way CO excitation in CO(1-0) • => study gas physics in ‘typical’ high-z galaxies • Image z=2-3 quasars and SMGs in CO(1-0) at 1 kpc resolution (‘bulk’ of the gas) • => study gas physics in extreme SF galaxies at peak epoch of cosmic AGN/SF activity • Use bandwidth for ‘blind’ CO searches (i.e., no spec-z’s) to identify all known SMGs • => does population peak at z=2-3 with long high-z tail, or broader distribution? • Use bandwidth to obtain multiple tracers of dense, SF gas in one shot, ‘for free’ • => dense gas-star formation relation vs. SF efficiency, gas density, chemistry, redshift EVLA

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