Gas Dynamics, AGN, Star Formation and ISM in Nearby Galaxies
Eva Schinnerer (MPIA)Eva Schinnerer (MPIA)
S. Haan, F. Combes, S. Garcia-Burillo, C.G. Mundell,S. Haan, F. Combes, S. Garcia-Burillo, C.G. Mundell,T. Böker, D.S. Meier , E. Emsellem, U. Lisenfeld, T. Böker, D.S. Meier , E. Emsellem, U. Lisenfeld,
D. Downes, D. CalzettiD. Downes, D. Calzetti
ISM in Nearby GalaxiesISM in Nearby GalaxiesWhy do we care?Why do we care?
Star Formation (SF)
Active Galactic Nuclei (AGN)
Gas Kinematics & ISM Properties
PDRs -- Photon Dominated RegionsXDRs -- X-ray Dominated RegionsShocks
Neutral Gas(Atomic &Molecular)
fuel
feedback
Spiral Arms (i.e. Density Waves)Large-scale Stellar barsDouble/Inner/Nuclear Barsnuclear Spiral Density Waves
Fueling nearby AGNs (e.g.NUGA - see talk by M. Krips): m=1 modes warps viscosity …
Gas Kinematics Main DriversOuter disk
center
Gas in BarsGas in BarsBasicsBasics
Meier & Turner (2004)
2
1
NGC 4303Schinnerer et al. (2002)
CO(1-0)
Roberts & StewarT (1987)
HI-NUGAHI-NUGA--
Gas Dynamics Gas Dynamics Over the Entire DiskOver the Entire Disk
VLA HI Survey of 16 Nearby Active GalaxiesVLA HI Survey of 16 Nearby Active Galaxies
AIM:AIM: Trace Gas Flow from Outer Disk to Very CenterTrace Gas Flow from Outer Disk to Very Center
S. Haan, PhD ThesisS. Haan, PhD Thesis
Seyferts
LINERs
Non-AGN
Inte
nsity
Map
Inte
nsity
Map
Inte
nsity
Map
Velo
city
Field
Velo
city
Field
Velo
city
Field
Findings (haan et al. 2008):LINERs - more large HI rings - more kinematically disturbed specialTime for Gas Flow in Barred Galaxies AGN activity linked to overall Disk
kinematics
22. Jan. 2008
Seyferts
LINERs
Non-AGN
HI
Inte
nsity
Map
HI
Inte
nsity
Map
HI
Inte
nsity
Map
Velo
city
Field
Velo
city
Field
Velo
city
Field
Findings (haan et al. 2008):LINERs - more large HI rings - more kinematically disturbed particular time for gas flow in bars
AGN activity linked to overall Disk kinematics
Finding Inflows using Gravity TorquesGas Dynamics within the DIsk
Haan et al. (in prep.)
Stellar Potential
Gas Distribution
Torque MapsShow In/Outflow
Angular MomentumtransferInflow
outflow
Noncircular Motions = inflow
Gas Flows and Mass Transfer EfficienciesGas Dynamics within the DIsk
Significant Gas Mass RedistributionLarger Gas Inflow Rates in Centers
Gas Flow Across Corotation Resonance
=> Strong Secular Evolution within Disks
Haan et al. (in prep.)
NGC 6946NGC 6946--
Central Mass Build-UpCentral Mass Build-Up
Molecular Gas Kinematics Molecular Gas Kinematics And And
Star Formation Tracers Star Formation Tracers at High Spatial Resolutionat High Spatial Resolution
Molecular Gas at ~10pc Resolutionmm-Interferometry
IRAM, Plateau de Bure
High Spectral (few km/s) & Spatial (<1’’) Resolution
Up-graded IRAM Plateau de Bure Interferometer:~ 0.3” resolution (at 1mm)3x more sensitive ~ 10x fasterMulti-Line Observations --> Chemistry
New Band: 2mm
Nuclear Region of NGC 6946Stars vs. Molecular Gas D=5.5 Mpc; 1” ~ 25 pc D=5.5 Mpc; 1” ~ 25 pc
PA ~ 35PA ~ 35oo; Incl. ~ 35; Incl. ~ 35oo
Large-Scale BarLarge-Scale Bar
50pc
HST H bandHST H band
Stellar Bar in NIR w/Length ~ 10” - 15”
PdBI 12CO(2-1)
20pc
Schinnerer, Böker, Emsellem, Lisenfeld (2006)
Gas Shows Classical Response Pattern for a Bar
Bar-Driven FuelingNGC6946
CO(2-1) Model
Inte
nsi
tyV
elo
city
400pc long barRedistributes gas
~ 107 Msun (r < 30 pc)
CR @ 260 pcbar=510 km/s kpc-1
Schinnerer, Böker, Emsellem & Lisenfeld (2006)
Where and When Stars Form Central 50pc of NGC6946
Schinnerer, Böker, Emsellem, Downes (2007)
PaPa HCN(1-0)HCN(1-0)3mm Continuum3mm Continuum
SFR ~ 0.1 Msun/yrAge ~ 5-10 Myr
SFR ~ 0.06 Msun/yrAge ~ < Myr
SFR ~ 0.1 Msun/yrAge ~ couple Myr
Star Formation in small Area over ~ 10 Myr
Fueling via Inner barMass Build-Up of ~ 106 Msun
In central 50pc(over last ~ 10 Myrs)
20pc
IC 342IC 342--
Nuclear Fueling &Nuclear Fueling &Star Formation FeedbackStar Formation Feedback
Impact of Nuclear Star FormationImpact of Nuclear Star FormationOnto the Gas FlowOnto the Gas Flow
Nuclear Cluster in IC342A Late-Type Barred Spiral
(Böker et al. 1997, 1999)(Böker et al. 1997, 1999)
Nuclear Stellar Cluster:
star formation~ 4 - 30 Myrs ago
Cluster mass ~ 107 Msun
HST V
D=3.3 Mpc; 1” ~ 16 pcPA ~ 35o; Incl. ~ 31o
Bar Length ~ 11 kpc
IC 342: Distribution of Molecular Gas
110 pc
OVRO CO (1-0)
H2 Mass (1’) ~ 4.4 x107 Msun
Masses ~ 106 Msun
Diameters ~ 20 - 50 pc(Wright et al. 1993, Levine et al. 1994)
Meier & Turner (2005)
Zooming in - IC342Gas vs. nuclear cluster
(Schinnerer, Böker, Meier, Calzetti, in prep.)
16pc
Molecular Gas & Dust CoincideGas reaches close To nuclear cluster(even more so in dense gas)
Ongoing Fueling? - IC342
H Bubble fills CO Cavity
stellar winds/SN appear to Shape inner edge of Eastern spiral arm
(obscured) HII region
(Schinnerer, Böker, Meier, Calzetti, in prep.)
Self-Regulation of Star FormationWhat is happening - Suggested Scenario
Before SF after SF
Nuclear SF changesNuclear SF changesGas FlowGas Flow
Timescales:vwinds (15-20 km/s): ~ 3 MyrsageSF ~ 4-30 Myrs
Energies:Emech (SB99) ~ 5e52 ergEGMC (2e6Msun) ~ 3e52 erg
Scenario plausible
(Schinnerer, Böker, Meier, Calzetti, in prep.)
Nuclear Star ClusterNuclear Star Cluster(almost) Shuts Off (almost) Shuts Off
Its Own SupplyIts Own Supply---> Feedback process!---> Feedback process!
What’s Next:What’s Next:--
Star Formation, ISM Star Formation, ISM And Gas KinematicsAnd Gas Kinematics
Molecular Gas ChemistryMolecular Gas ChemistryUtilizing Multiple MoleculesUtilizing Multiple Molecules
Next Steps - NGC 6946Chemistry
Schinnerer, Meier, Böker, Downes, Emsellem in prep.Schinnerer, Meier, Böker, Downes, Emsellem in prep.
Locate: star forming gas(chemically) fresh gas [from atomic reservoir](chemically) altered gas (SF, Gas Dynamics)
Census of multi-phase ISM
(Gas) Kinematics & Star Formation
KinematicsKinematics --- ionized Gas (different ISM Phase)--- ionized Gas (different ISM Phase) --- Stellar Velocity Fields/Dispersion--- Stellar Velocity Fields/Dispersion => Better Models of Kinematics => Better Models of Kinematics (see Talk by G. Dumas)(see Talk by G. Dumas)
Star FormationStar Formation --- History, Population, Location--- History, Population, Location --- Energy Injection into ISM--- Energy Injection into ISM --- Feedback Processes --- Feedback Processes
Summary & Conclusion Gas KinematicsGas Kinematics --- Ongoing Gas Redistribution within Disk--- Ongoing Gas Redistribution within Disk --- bars work (in general, Small & Large)--- bars work (in general, Small & Large) --- Sustained Nuclear fueling for > 10 Myr--- Sustained Nuclear fueling for > 10 Myr Nuclear Star FormationNuclear Star Formation --- can alter gas flow--- can alter gas flow --- self-regulated fueling--- self-regulated fueling => repetitive SF=> repetitive SF time-variable time-variable (models)(models)
Future BrightFuture Bright:: ALMAALMA
ALMA siteALMA site
ALMA test facilityALMA test facility
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