Imaging star-forming gas in nearby galaxies with ALMA

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Imaging star-forming gas in nearby galaxieswith
ALMA

• Jean Turner (UCLA)

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ALMA studies of star formation on galactic scales
complement Galactic and high z studies
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ALMA studies of star formation on galactic scales
complement Galactic and high z studies

• Observed Stellar populations, Hubble sequence,
  beads on a string, Toomre Q

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ALMA studies of star formation on galactic scales
complement Galactic and high z studies

• Observed Stellar populations, Hubble sequence,
  beads on a string, Toomre Q
• What is the relation of spiral structure to star
  formation?

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ALMA studies of star formation on galactic scales
complement Galactic and high z studies

• Observed Stellar populations, Hubble sequence,
  beads on a string, Toomre Q
• What is the relation of spiral structure to star
  formation?
• Observed LIR/MH2 well-correlated, Schmidt law,
  excellent correlation of HCN and LIR (Gao
  Solomon 2005)

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ALMA studies of star formation on galactic scales
complement Galactic and high z studies

• Observed Stellar populations, Hubble sequence,
  beads on a string, Toomre Q
• What is the relation of spiral structure to star
  formation?
• Observed LIR/MH2 well-correlated, Schmidt law,
  excellent correlation of HCN and LIR (Gao
  Solomon 2005)
• How do properties of the gas atomic vs
  molecular, dense vs diffuse gas determine star
  formation?

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ALMA resolution 10 maslt1 pc at Virgoresolve
individual SF regions, structure around AGN in
the local universe50 pc out to 900 MpcGMCs,
spiral features, galactic structure for a large
sample of neaby galaxies
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Direct imaging of extragalactic star-forming
regions ALMA continuum
Continuum sensitivities 10 ?Jy in an hour

• Massive HII regions via their free-free emission
• Super star clusters imaging to 50 Mpc
• Orions image to 10Mpc, detect to Virgo
• Dust emission from low and high mass stars
• More sensitive than free-free
• Local Group, 10 mas .04 pc 10,000 AU

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Direct imaging of molecular gas ALMA line
emission
Line brightnesses 0.01K in 10 hours

• Imaging of molecular clouds in CO and other
  molecules

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Care and feeding of AGN
NGC 1068 Seyfert 2 CO(1-0) CO(2-1)
Plateau de Bure Interf.
Schinnerer et al. 2000
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Nurturing of star formation in galaxies
N. Sharp, NOAO
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Nurturing of star formation in galaxies
CO BIMA-SONG
N. Sharp, NOAO
Helfer et al. 2003
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Nurturing of star formation in galaxies
CO BIMA-SONG
F. Calvert, A. Block, NOAO/AURA/NSF
Helfer et al. 2003
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ALMA is designed to detect extended structure
M83
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ALMA is designed to detect extended structure
CO (green) NRAO 12 meter telescope HI (red)
VLA (NRAO/AUI/NSF)
M83
AAT D. Malin
Crosthwaite et al. 2003
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ALMA can study gas and interactions
VLA NRAO/AUI/NSF Yun,
Ho, Lo 1994
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The world of molecules
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Detecting molecular gas
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Detecting molecular gas
H2 is silent unless it is hot (100
K)
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Detecting molecular gas
H2 is silent unless it is hot (100 K) CO is a
pretty good tracer, easily excited (5.5 K, low
densities), abundant, bright.
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Detecting molecular gas
H2 is silent unless it is hot (100 K) CO is a
pretty good tracer, easily excited (5.5 K, low
densities), abundant, bright. How good is
pretty good? To factor of two within Galaxy
(gamma rays) Overpredicts gas mass in
metal-rich galactic centers. Situation in low
metallicity galaxies unclear Freeze-out in
densest clouds
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Detected interstellar molecules
H2 HD H3 H2D CH CH C2 CH2 C2H
C3 CH3 C2H2 C3H(lin) c-C3H CH4 C4 c-C3H2
H2CCC(lin) C4H C5 C2H4 C5H H2C4(lin)
HC4H CH3C2H C6H HC6H H2C6 C7H CH3C4H
C8H C6H6 OH CO CO H2O HCO HCO HOC
C2O CO2 H3O HOCO H2CO C3O CH2CO HCOOH
H2COH CH3OH CH2CHO CH2CHOH CH2CHCHO HC2CHO
C5O CH3CHO c-C2H4O CH3OCHO CH2OHCHO
CH3COOH CH3OCH3 CH3CH2OH CH3CH2CHO (CH3)2CO
HOCH2CH2OH C2H5OCH3 (CH2OH)2CO NH CN N2 NH2
HCN HNC N2H NH3 HCNH H2CN HCCN
C3N CH2CN CH2NH HC2CN HC2NC NH2CN
C3NH CH3CN CH3NC HC3NH HC4N C5N
CH3NH2 CH2CHCN HC5N CH3C3N CH3CH2CN HC7N
CH3C5N? HC9N HC11N NO HNO N2O HNCO NH2CHO
SH CS SO SO NS SiH SiC SiN SiO SiS
HCl NaCl AlCl KCl HF AlF CP PN H2S
C2S SO2 OCS HCS c-SiC2 SiCN SiNC NaCN
MgCN MgNC AlNC H2CS HNCS C3S c-SiC3
SiH4 SiC4 CH3SH C5S FeO
DEMIRM
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Chemistry in Galaxies

• Pioneering single dish work on the IRAM 30m
• Henkel, Mauersberger et al., resolutions 30
  (300-500 pc in even the closest galaxies)
• Galaxies can have distinctive chemistries

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Imaging Chemistry in Galaxies

• IC 342 Owens Valley Millimeter Array

N2H HNC HC3N C2H C34S
HNCO CH3OH
Meier Turner 2005
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Imaging Chemistry in Galaxies

• IC 342 Owens Valley Millimeter Array

Meier Turner 2005
PC Axis 1 Density-weighted mean column density
Gas density CO, N2H, HCN
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Imaging Chemistry in Galaxies

• IC 342 Owens Valley Millimeter Array

Meier Turner 2005
PC Axis 1 Density-weighted mean column density
PC Axis 2 Shock tracers vs PDR molecules
C2H PDR Methanol, HCNO shocks
Gas density CO, N2H, HCN
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Imaging Chemistry in Galaxies

• IC 342 Owens Valley Millimeter Array
• M82 BIMA Array
• Not detected in M82 maps shock tracers SiO,
  HNCO, CH3OH

Meier Turner 2005, 2006
X X
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ALMA Imaging star-forming gas in nearby
galaxiessummaryALMA will be a powerful
imaging device HII regions (free-free)dust
emission (low and high mass SF)molecular clouds
on sizescales of 1pc (SF regions, AGN)to
galaxy-wide, out to hundreds of MpcIT WILL BE
GREAT!
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LMC
ALMA