Star Formation and Dynamics in Galaxies

Santiago GARCIA-BURILLO

Observatorio Astronómico Nacional (OAN)-Spain

The Dusty Universe, October 27-29, 2004, Paris, France

• Dynamics of galaxy nuclei-AGN feeding -SB-AGN connection

•Dynamics of galaxy disks-Resolving individual molecular clouds-Testing density wave theories: spiral waves and bars-Probing the disk-halo interface: molecular outflows

OUTLINE

• Molecular gas chemistry in galaxies (SB, AGN)-Shock chemistry in SB-PDR chemistry in SB-XDR chemistry in AGN

CO lines

Beyond CO...

Dynamics of Disks (I): Resolving Molecular Clouds

-> M31: closest spiral galaxy (1’’=4pc) with well-known distance.-> 30m + PdBure Interferometer CO(1-0) and CO(2-1) maps->Interferometer maps resolve individual molecular clouds--> determination of molecular cloud properties: sizes, vel.disp, temperatures and clouds masses....

CO(1-0) 30m map of M31

The case of M31: Neininger et al 1998; Guelin et al 2000, 2004; Muller 2003

30m map Bure ‘minmaps’

Addressing cloud mass determination from virial theorem:-->standard: it does not work!-->balistic: it works with X=1-2!-->LOWER CO--to--H2 conversion factor (also) for disks, not only for nuclei!

ALMA will resolve individual molecular clouds out to D=50Mpc

12CO(1-0) OVRO+30m

Aalt

o e

t al. (

19

99

) 12CO(1-0)

Dynamics of Disks (II): Spiral Waves The case of M51: Schinnerer et al 2004

-> M51: grand design spiral galaxy (1’’=45pc)-> OVRO (Aalto et al. 1999) +30m (Garcia-Burillo et al. 1993) : 12CO(1-0), 12CO(2-1), 13CO(1-0)C18O(1-0)->Interferometer maps identify GMA--> determination of molecular gas properties on spiral arms and interarm regions as a function of radius.

A challenging case study for density wave theory:-->Dynamics: strong streaming motions: ~50-100km/s on 100pc scales -->SF trigger: Halpha ‘a long way’ downstream

ALMA will resolve molecular spiral arms in galaxies out to D=500Mpc

Bars as engines of galactic evolutionPattern speed ‘evolution´ in bars, from Bournaud and Combes 2002

Decoupled bars in M100, from García-Burillo et al 1998

MaMa

-->Simulations suggest bar instabilities experience significant secular evolution depending on gas accretion(Bournaud and Combes 2002; Englmaier and Sloshman 2004).

Dynamics of Disks (III): Bars

--> CO mapping of bars in galaxy disks on several scales provide constraints to:- bar pattern speeds - feasibility of decoupling of bars fully tested by observations.

-->Bar properties as a function of z?(Jogee et al 2004)

ALMA will allow studies of molecular bars in galaxies out to D=500-1000Mpc

•IRAM PdBI one-field map shows SiO emission extends out of galaxy plane!: chimney+supershell.

SiO supershell

SiO chimney

OVRO CO(1-0) map :Walter et al 2002

Molecular gas drawn out of galaxy disks: starbursts

M82: a huge molecular gas halo! (Seaquist and Clark 2001, García-Burillo et al 2001, Walter et al 2002)

The tip of the iceberg!

•ALMA will make possible high-resolution mapping of extreme starbursts as M82: key to understand high-z galaxies !

Dynamics of Disks (IV): The Disk-Halo Interface

PdBI SiO(2-1) map: García-Burillo et al 2001

• Dynamics of galaxy nuclei-AGN feeding -SB-AGN connection

•Dynamics of galaxy disks-Resolving individual molecular clouds-Testing density wave theories: spiral waves and bars-Probing the disk-halo interface: molecular outflows

OUTLINE

• Molecular gas chemistry in galaxies (SB, AGN)-Shock chemistry in SB-PDR chemistry in SB-XDR chemistry in AGN

CO lines

Beyond CO...

->AGN fuelled with material originally away from gravitational field of BH: problem of angular momentum removal.

-> Critical scale for AGN feeding: <100pc. AGN duty cycle is short!

-> Search for correlation with `secondary instabilities’ from 500pc to 50 pc: nuclear bars? spiral gas waves?, nuclear-warps? m=1 modes? ... No consensus on the driving mechanism!...(only one? several?...)

What sets on activity in galaxies ‘at present’ ...?

( Combes 2000-2004; Wada et al 2000-2004; Englmaier & Shlosman 2000; Shlosman 2001; Maciejewski et al 2002, 2004; Knapen 2001, 2004; Jogee 2004; Laine et al 2002; Garcia-Burillo et al 2000, Schinnerer et al 2000.......and many others!)

Dynamics of Nuclei : Feeding AGN (I)

--> High spatial resolution (0.5’’-1”) CO observations paramount to reach ‘critical’ scales: <50-100pc

T/LINER

LINER/SEYF. 1

LINER

HII/T

SEYF. 1

SEYF. 2

SEYF. 2

LINER T/LINER

SEYF. 2

SEYF. 2

T/SEYF. 2

NUGA: a CO survey of low-L AGN with IRAM PdbI: García-Burillo, Combes, Eckart et al 2003, 2004

Dynamics of Nuclei : Feeding AGN (II)

~4x108 Msun ‘trapped’ in starburst ring

~107Msun at r<200 pc from AGN:

-1/Central ‘torus’ ~106Msun (torus) --> feeding in the past -2/Bridge of ~107Msun linked to filamentary spiral seen in J-H HST map --> (low level) ongoing feeding

García-Burillo, Combes, Schinnerer et al 2004

Observational evidence of feeding?....

Dynamics of Nuclei : Feeding AGN (III)

NGC6951

NGC4826

CO(2-1) on J-H/HST

CO(2-1) on B-I/HST

TRANSITION object

Seyfert 2

~108Msun at r<200 pc from AGN:

-kinematics suggests outflow, not inflow! -m=1 instability inhibits feeding at present? --> no evidence of ongoing feeding

Garcia-Burillo, Combes, Schinnerer et al 2004

Gravity Torque Maps Efficiency of Torques

Dynamics of Nuclei : Feeding AGN (IV)

NGC4826

NGC6951 Seyfert 2

-->gravity torques give angular momentum to gas at r<600pc --> no ongoing feeding (agreementwith CO diagnostic)

TRANSITION object

->HST NIR images (0.2’’) allow derivation of stellar gravity torques on molecular gas disk from CO maps (0.5’’).

-->gravity torques remove angular momentum from gas down to r=400pc -->gravity torques have no role at r<200pc! --> ongoing feeding maintained by transitory mechanism?

Wide range of instabilities at r~10-500 pc from AGN: m=2, 1 - like and ‘stochastic’ perturbations. ---> Not all instabilities feed AGN, some do feed nuclear starbursts. ---> Some instabilities may inhibit AGN feeding.

High-resolution (0.5’’) CO maps of AGN allow analysis of stellar gravity torques on gas.---> AGN feeding in Seyferts in two steps:

1/ First, stellar torques feed nuclear SB on scales of ~a few 100pc. 2/ A ‘transitory’ mechanism involving little gas feeds directly AGN

Dynamics of Nuclei : Feeding AGN (IV)

•ALMA will make high-resolution and high-sensitivity maps of a significant number of AGN hosts , zooming on the inner 10pc playground.

• Dynamics of galaxy nuclei-AGN feeding -SB-AGN connection

•Dynamics of galaxy disks-Resolving individual molecular clouds-Testing density wave theories: spiral waves and bars-Probing the disk-halo interface: molecular outflows

OUTLINE

• Molecular gas chemistry in galaxies (SB, AGN)-Shock chemistry in SB-PDR chemistry in SB-XDR chemistry in AGN

CO lines

Beyond CO...

Evolutionary trends in SB can be tracked down by observation of different chemical tracers

I/ ONSET OF THE NUCLEAR STARBURST: gas infall driven by density waves and/or tidal forces.

II/ MASSIVE STAR FORMATION BURSTS: Young Stellar Objects and first SN explosions

III/ BIPOLAR GIANT OUTFLOW: gas plane breaks out due to blast waves of SN remnants.

PHASES

•Gas compression, HI H2, cloud-cloud

collisions driving large-scale SHOCKS.

PROCESSES

•UV field from massive stars create HII regions and PDR locally in disk.

• SHOCKS in YSO in disk

•XDR when AGN in disk.

•Strong UV fields create giant PDR in disk

•Expansion of gas heated by SN entrains neutral gas into halo driving SHOCKS

•PDR / SHOCKS in halo?

Extragalactic Chemistry (I) Energetic Processes in SB & AGN (intense UV/X Radiation, Shocks,Cosmic Rays...)

• Different molecules provide

diagnostic tools to explore starburst evolution: M82 and NGC253 show different chemistries

M82

NGC253

Herschel (HIFI) will make multilines /multispecies studies in the submm/IR for nearby SB

M82 and NGC253 spectra (~4GHz broad) by S. Martín (private communication)

2mm Survey (~40GHz broad) of the NGC253 with IRAM 30m (Martín et al. 2003, 2004)

NGC253

Extragalactic Chemistry(II): Expanding the Frequency Range

LINE SURVEYS

->Pioneering work of R. Mauersberger+C. Henkel (80-90’s) done with 30m telescope (12’’-27’’ resolution) in some galaxies for a limited number of molecular species.

Extragalactic Chemistry(III): Using Interferometers

OVRO maps of IC342 (Meier and Turner 2004)

High spatial resolution is paramount to probe chemical differentation in galaxies!

•SiO traces shocks in the disk-halo interface in M82: giant outflow, evolved starburst.

•SiO traces shocks in the disk of NGC253 (SF, density waves...): less evolved starburst.

High spatial resolution needed to trace evolution in starburstsHigh spatial resolution needed to trace evolution in starbursts

NGC253 M82

SiO IRAM PdBI map in NGC253 from García-Burillo et al 2000.

10´´

SiO IRAM-PdBI map (contours) from García-Burillo et al. 2001 on CO (2-1) map from Weiss et al 2001 (colour ) in M82.

Extragalactic Chemistry(IV): Large-Scale Shocks

--->Widespread HCO emission detected in PdBI map of the nucleus of M82 (García-Burillo et al 2002)

--->Global HCO abundances comparable to PDR: X(HCO)~4x10-10(Hollis & Churchwell, 1983; Snyder et al 1985; Schilke et al 2001)

--->Interferometer map shows strong variations of X(HCO) within disk: PDR Chemistry propagates.

--->Detection of HOC+, emission of small hydrocarbons and large CN/HCN ratios corroborate PDR chemistry scenario (Fuente et al 2004)

NeII contours(Achtermann & Lacy 1995) on HCO map

Extragalactic Chemistry(V): PDR Chemistry-->M82 disk is a giant PDR of 600 pc size! (Mao et al 2000, García-Burillo et al 2002; Fuente et al 2004)

HCO PdBI map (García-Burillo et al 2002)

CO(1-0) (PdBI;Schinnerer et al. 00)

Molecular Gas Inventory of the CND of NGC1068

-->X-ray driven chemistry models explain abundance ratios measured in the CND of NGC1068 (Usero et al 2004)

NGC1068

Extragalactic Chemistry(VI): XDR Chemistry

Usero et al. 2004, A&A, 419

-->X-rays suspected to heavily influence molecular gas chemistry in the nuclear disks of AGN (Tacconi et al 1994, Maloney et al 1996, Kohno et al 2002, Usero et al 2004)

-->Influence of X-rays on ULIRGs and embedded AGN at high z to be explored with ALMA