New tales of molecular gas in galaxies: (not so) near and far

Jeff Wagg Max-Planck/NRAO Fellow NRAO – Socorro

NRAO postdoc symposium Socorro April 29, 2009

“Solid science, but there are enough high-z CO detections now that the prospect of adding a few more is not overly exciting”

Comment from GBT referee, April 2007

CO line emission as a tracer of molecular gas at high-redshift: fueling star-formation and AGN activity

Obs

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Molecular gas mass

Riechers et al. 2006

MH2 ~ 0.8 LCO [Msun] ULIRGS (Downes & Solomon 1998)

MH2 ~ 4.6 L CO [Msun] Milky Way (e.g. Solomon & Barrett 1991)

Weiss et al. 2005

● CO molecule exhibits rotational transitions between quantum numbers Jupper -> Jlower at frequency spacings: Jupper × 115 GHz

● CO emission line “spectral energy distribution” of a galaxy indicates density and temperature of gas

CO line emission as a tracer of molecular gas: fueling star-formation and AGN activity

● BzK galaxies: star-forming galaxies identified in (B-z) vs. (z-K) diagram (Daddi et al. 2004)

● CO J=2-1 with PdBI: large masses of molecular gas (1010 Msun) forming stars with low efficiency (~100 Msun/yr)

Low excitation molecular gas in “normal” galaxies at z~1.5

CO J=1-0 - GBT/Q-band, 12hrs on (Aravena, Wagg, Carilli ea in prep.)

Daddi et al. 2008

Dannerbauer et al. in

prep

Outline

• molecular gas in ULIRG-to-QSO transition objects at z ~ 0.3

• measuring redshifts for submm galaxies: water megamasers?

• molecular gas and the epoch of reionization

Molecular gas in ULIRG-to-QSO transition objects

1. ultraluminous infrared galaxy (ULIRG): merger of two gas-rich galaxies

2. AGN and starburst evolve coevally within ULIRG

3. optically luminous QSO emerges after dust is shed

Molecular gas in ULIRG-to-QSO transition objects

1. ultraluminous infrared galaxy (ULIRG): merger of two gas-rich galaxies

2. AGN and starburst evolve coevally within ULIRG

3. optically luminous QSO emerges after dust is shed

Lipari et al 1994; Canalizo & Stockton 2001

IRAS 00275-2859

Molecular gas in ULIRG-to-QSO transition objects

CO emission in luminous QSOs at low redshift

Optical/HST: most luminous QSOs are early-type

Alloin et al 1992, Haas et al 2000, Evans et al 2001, Scoville et al 2003, Bertram et al 2007

Dunlop et al 2003, Floyd et al 2004

Molecular gas in a “Naked” QSO: HE0450-2958 at z=0.286 Papadopoulos, Feain, Wagg & Wilner 2008

Contours: CO J=1-0 (ATCA)Greyscale: HSTcross - optical quasarstar: ULIRG

• AGN with no apparent host galaxy (Magain et al 2005)

• strong IRAS source: SFR~370 Msun/yr (de Grijp et al 1987)

• ATCA and SMA CO imaging reveal cold gas: MH2 ~(1-2)×1010 Msun R32 < 0.39 (R32~0.65 for ULIRGs)

• gas feeding both AGN and starburst?

Single-dish JCMT spectra and future workWagg, Papadopoulos, Ivison & Aravena

CO J=4-3 spectra - JCMT/Harp-B

HST imaging Floyd et al 2004

• broad CO J=4-3 lines: ~1000km/s

• tentative detection of CO J=1-0 in 1821+643 at z=0.287 with CARMA

• combination of PdBI, CARMA, ALMA will isolate molecular gas in ULIRG->QSO transition objects

CO J=1-0 CARMA (15 hrs)

Using molecular emission lines to measure redshifts for massive, high-redshift ULIRGs

Chapman et al. 2005 GBT K-band Wagg et al 2007

850um Hubble Deep FieldHughes et al. 1998

HDF850.5Wang et al 2007

CO J=4-3? PdBIDaddi et al. 2009

GN20 CO J=4-3 Pope et al 2005 Daddi et al. 2009

H2O megamasers at high-redshift I: detection in lensed quasars

Castangia et al 2008

H2O megamaser at z=2.64EVLA/Effelsberg Impellizzeri et al 2008

• H2O masers at 22.235 GHz arise in sites of star-formation or AGN activity (see Lo 2005 for review)

• tentative correlation between H2O line luminosity and FIR luminosity in nearby FIR bright galaxies (Castangia et al 2008)

H2O megamasers at high-redshift II: EVLA searches in lensed starbursts• Edmonds, Wagg et al. 2009• Wagg & Momjian, AJ, submitted

CO J=3-2 – PdBI Kneib et al 2005

EVLA C-band spectra

• FIR luminosity in submm galaxies mainly powered by star-formation (e.g. Alexander et al 2005)

• H2O “kilomasers” found in nearby star-forming galaxies (e.g. Henkel et al. 2005)

• SMMJ16359: LH2O < 1890 Msun (dV = 80 km/s)

IRAM PdBI

• LFIR~ 1e13 Lo

• Mgas ~ 2e10 Mo

• Mdust ~ 4e8 Mo

Ran Wang et al. in prep.

IRAM PdBI

6 x 15m antennas

French Alps

1 – 3 mm

Molecular gas in galaxies during reionization I: CO in z > 5.7 quasars

Molecular gas in galaxies during reionization II: CO in Ly emittersWagg, Kanekar & Carilli 2009

HCM 6A

z=6.56 Hu et al 2002

IOK-1

z=6.96 Iye et al 2006

CO J=1-0 GBT Ku-band

• LAEs: `normal’ star-forming galaxies responsible for reionization

• stellar masses: 108 – 10 Msun

• SFRs: 3 – 140 Msun/yr

• dusty? (Chary et al. 2005; Finkelstein et al 2009)

• No CO J=1-0 detected with GBT - HCM6A: L’CO < 6.1E+9 (dV/300)1/2 K km/s pc2 MH2 < 4.9E+9 (dV/300)1/2 (XCO/0.8) Msun

• First sensitive constraints on the presence of molecular gas in LAEs

Summary

• molecular gas in ULIRG-to-QSO transition objects at z ~ 0.3

• measuring redshifts for submm galaxies: water megamasers?

• molecular gas and the epoch of cosmic reionization

• interferometric imaging of CO line emission reveals evidence for wet-dry mergers at z~0.3

• broad CO lines detected in quasar host galaxies

• megamasers not detected in strongly lensed, starburst galaxies at z~2.5

• broadband CO emission line searches likely the best means of measuring redshifts for submm galaxies

• total number of quasars detected in high-J CO line emission at z > 5.7: eight

• sensitive searches for CO line emisison in z>6.5 LAEs suggest small quantities of molecular gas

Acknowledgements

Thank you!!

Chris Carilli, the Max-Planck Society and the Humboldt Foundation

Dale, Miller and the NRAO

NRAO collaborators: Nissim, Frazer, Emmanuel, Ron, D.J. , Paul and Manuel

Students: Michael Carilli, Robert Edmonds and Ran Wang

AOC staff and fellow postdocs

Molecular gas in the radio quiet quasar: 1821+643 at z=0.297 Wagg, Papadopoulos & Ivison in prep.

Floyd et al. 2004

CO J=1-0 CARMA (15 hrs)

• 1821+643: radio-quiet quasar

• extreme FIR luminosity ???

• CO associated with nearby, interacting galaxy, not elliptical