Normal/Starburst Normal/Starburst

Galaxies at Galaxies at

Low/Intermediate-z Low/Intermediate-z

with ALMAwith ALMA

Normal/Starburst Normal/Starburst

Galaxies at Galaxies at

Low/Intermediate-z Low/Intermediate-z

with ALMAwith ALMA

Bologna, 2005 June 6 Bologna, 2005 June 6 Bologna, 2005 June 6 Bologna, 2005 June 6

Strong limitation of Current mm

Interferometers WHY ALMA?

OVRONobeyama Millimeter Array

In sensitivity (PdBI, the most sensitive)In Ang. Res. (bs max = 2km for BIMA, ~500m others)In Freq. Coverage (ALMA open sub-mm window)In Imaging capability (6 to 10 antennas only) ALMA @1.3 mm vs. PdBI sensitivity Continuum factor 100 better (6 µ Jy/beam in 1 hr) Spectral line factor 30 better (1.1 mJy/beam in 10 hr)

ALMA factor 10-100 better in resolution

IRAM

Primary Goals for ALMA in Primary Goals for ALMA in Extragalactic AstronomyExtragalactic Astronomy

Primary Goals for ALMA in Primary Goals for ALMA in Extragalactic AstronomyExtragalactic Astronomy

The ability to detect spectral line emission from CO or CI in a normal galaxy like the Milky Way at a redshift of 3, in less than 24 hours of observation.

The ability to provide precise images at an angular resolution of 0.1” or better (0.01” at 650 GHz) to map the dust/molecular clouds structure in distant galaxies

The ability to detect spectral line emission from CO or CI in a normal galaxy like the Milky Way at a redshift of 3, in less than 24 hours of observation.

The ability to provide precise images at an angular resolution of 0.1” or better (0.01” at 650 GHz) to map the dust/molecular clouds structure in distant galaxies

Detecting normal galaxies Detecting normal galaxies at z=3at z=3Detecting normal galaxies Detecting normal galaxies at z=3at z=3

CO emission now CO emission now

detected in 25 z>2 detected in 25 z>2

objects. To date objects. To date

only in luminous only in luminous

AGN and/or AGN and/or

gravitationally gravitationally

lensed lensed in 1to 2 days in 1to 2 days

of total obs. time.of total obs. time. Normal galaxies are Normal galaxies are 20 20 to 30 times fainterto 30 times fainter..

CO emission now CO emission now

detected in 25 z>2 detected in 25 z>2

objects. To date objects. To date

only in luminous only in luminous

AGN and/or AGN and/or

gravitationally gravitationally

lensed lensed in 1to 2 days in 1to 2 days

of total obs. time.of total obs. time. Normal galaxies are Normal galaxies are 20 20 to 30 times fainterto 30 times fainter..

Detecting normal galaxies at Detecting normal galaxies at z=3z=3Detecting normal galaxies at Detecting normal galaxies at z=3z=3

• Total CO luminosity of Milky Way: L’co(1-0) =

3.7x108 K km s-1pc2 (Solomon & Rivolo 1989).• COBE found slightly higher luminosities in

higher transitions (Bennett et al 1994) → adopt L’

co = 5x108 K km s-1pc2.

• At z=3 → observe (3-2) or (4-3) transition in the 84-116 GHz atmospheric band → need to correct, but also higher TCMB providing higher background levels for CO excitation.

• Different models predict brighter or fainter higher-order transitions. Few measurements of CO rotational transitions exist for distant quasars and ULIRGs, but these are dominated by central regions.

• → Assume L’co(3-2) / L’

co(1-0) = 1.

• Total CO luminosity of Milky Way: L’co(1-0) =

3.7x108 K km s-1pc2 (Solomon & Rivolo 1989).• COBE found slightly higher luminosities in

higher transitions (Bennett et al 1994) → adopt L’

co = 5x108 K km s-1pc2.

• At z=3 → observe (3-2) or (4-3) transition in the 84-116 GHz atmospheric band → need to correct, but also higher TCMB providing higher background levels for CO excitation.

• Different models predict brighter or fainter higher-order transitions. Few measurements of CO rotational transitions exist for distant quasars and ULIRGs, but these are dominated by central regions.

• → Assume L’co(3-2) / L’

co(1-0) = 1.

Detecting normal galaxies at Detecting normal galaxies at z=3z=3Detecting normal galaxies at Detecting normal galaxies at z=3z=3

• For ΛCDM cosmology, Δv=300 km/s, the expected peak CO(3-2) flux density is 36 µJy.

• 5σ detection achievable with ALMA in 12h on source (16h total time)

• For ΛCDM cosmology, Δv=300 km/s, the expected peak CO(3-2) flux density is 36 µJy.

• 5σ detection achievable with ALMA in 12h on source (16h total time)

ALMA AS A REDSHIFT MACHINEALMA AS A REDSHIFT MACHINEALMA AS A REDSHIFT MACHINEALMA AS A REDSHIFT MACHINE

• >50% of the FIR/submm background are >50% of the FIR/submm background are submm galaxies.submm galaxies.

• Trace heavily obscured star-forming Trace heavily obscured star-forming galaxies.galaxies.

• Optical/near-IROptical/near-IR

identification very difficult.identification very difficult.• Optical spectroscopy: Optical spectroscopy:

<z>~2.4.<z>~2.4.• Confirmation needed Confirmation needed

with CO spectroscopy. with CO spectroscopy.

• >50% of the FIR/submm background are >50% of the FIR/submm background are submm galaxies.submm galaxies.

• Trace heavily obscured star-forming Trace heavily obscured star-forming galaxies.galaxies.

• Optical/near-IROptical/near-IR

identification very difficult.identification very difficult.• Optical spectroscopy: Optical spectroscopy:

<z>~2.4.<z>~2.4.• Confirmation needed Confirmation needed

with CO spectroscopy. with CO spectroscopy.

SCUBA image of the HDF-N

mm continuum contours + HST optical image for the strongest SCUBA source in the HDF-N

Hughes et al. 1998 Downes et al. 2000

ALMA AS A REDSHIFT MACHINEALMA AS A REDSHIFT MACHINEALMA AS A REDSHIFT MACHINEALMA AS A REDSHIFT MACHINE

• ALMA will provide 0.1” images of submm sources found in bolometer surveys (LABOCA/APEX, SCUBA-2/JCMT) or with ALMA itself.

• 3 frequency settings will cover the entire 84-116 GHz band → at least one CO line. (1h per source)

• Confirm with observation of high/lower order CO line. (1h per source)

• ALMA will provide 0.1” images of submm sources found in bolometer surveys (LABOCA/APEX, SCUBA-2/JCMT) or with ALMA itself.

• 3 frequency settings will cover the entire 84-116 GHz band → at least one CO line. (1h per source)

• Confirm with observation of high/lower order CO line. (1h per source)

PHOTOMETRIC REDSHIFTS PHOTOMETRIC REDSHIFTS FROM FLUX RATIOSFROM FLUX RATIOS

PHOTOMETRIC REDSHIFTS PHOTOMETRIC REDSHIFTS FROM FLUX RATIOSFROM FLUX RATIOS

• At z<1,At z<1, the 1.4 GHz radio to 350 GHz the 1.4 GHz radio to 350 GHz submm flux ratio can provide an estimate submm flux ratio can provide an estimate of the source redshift (Carilli & Yun 1999)of the source redshift (Carilli & Yun 1999)

NB: valid for SBs. In AGNs radio excess is NB: valid for SBs. In AGNs radio excess is possiblepossible

• At higher z,At higher z, this flux ratio saturatesthis flux ratio saturates

one can use broad band SEDs obtained one can use broad band SEDs obtained by observing in different ALMA bands to by observing in different ALMA bands to constrain the position of the redshifted 50-constrain the position of the redshifted 50-80 K hot dust peak 80 K hot dust peak

Photometric methods not very accurate for Photometric methods not very accurate for single single

gals but useful to determine global z gals but useful to determine global z distributionsdistributions

• At z<1,At z<1, the 1.4 GHz radio to 350 GHz the 1.4 GHz radio to 350 GHz submm flux ratio can provide an estimate submm flux ratio can provide an estimate of the source redshift (Carilli & Yun 1999)of the source redshift (Carilli & Yun 1999)

NB: valid for SBs. In AGNs radio excess is NB: valid for SBs. In AGNs radio excess is possiblepossible

• At higher z,At higher z, this flux ratio saturatesthis flux ratio saturates

one can use broad band SEDs obtained one can use broad band SEDs obtained by observing in different ALMA bands to by observing in different ALMA bands to constrain the position of the redshifted 50-constrain the position of the redshifted 50-80 K hot dust peak 80 K hot dust peak

Photometric methods not very accurate for Photometric methods not very accurate for single single

gals but useful to determine global z gals but useful to determine global z distributionsdistributions

THE EFFECT OF DUST ON THE THE EFFECT OF DUST ON THE STAR FORMATION HISTORYSTAR FORMATION HISTORY

THE EFFECT OF DUST ON THE THE EFFECT OF DUST ON THE STAR FORMATION HISTORYSTAR FORMATION HISTORY

Cosmic SFR density evolution with z show a peak Cosmic SFR density evolution with z show a peak at at

z = 1.5 – 3 (Blain et al. 2002) z = 1.5 – 3 (Blain et al. 2002)

BUT effect of dust unknown since current sub-mm BUT effect of dust unknown since current sub-mm obs. limited to most extreme systems at such obs. limited to most extreme systems at such distancesdistances

ALMA sensitivities of 10’s of ALMA sensitivities of 10’s of µJy + sufficient Jy + sufficient resolutionresolution

to avoid confusion (plaguingto avoid confusion (plaguing

Single Dish obs.)Single Dish obs.)

normal star-forming gals normal star-forming gals

at high z at high z

(SFR~10’s of M(SFR~10’s of MSunSun/yr)/yr)

Cosmic SFR density evolution with z show a peak Cosmic SFR density evolution with z show a peak at at

z = 1.5 – 3 (Blain et al. 2002) z = 1.5 – 3 (Blain et al. 2002)

BUT effect of dust unknown since current sub-mm BUT effect of dust unknown since current sub-mm obs. limited to most extreme systems at such obs. limited to most extreme systems at such distancesdistances

ALMA sensitivities of 10’s of ALMA sensitivities of 10’s of µJy + sufficient Jy + sufficient resolutionresolution

to avoid confusion (plaguingto avoid confusion (plaguing

Single Dish obs.)Single Dish obs.)

normal star-forming gals normal star-forming gals

at high z at high z

(SFR~10’s of M(SFR~10’s of MSunSun/yr)/yr)

PRECISE MAPPING OF SUB-MM SOURCESPRECISE MAPPING OF SUB-MM SOURCESPRECISE MAPPING OF SUB-MM SOURCESPRECISE MAPPING OF SUB-MM SOURCES

• Follow-up with ALMA:

• High resolution CO imaging to determine morphology (mergers?), derive rotation curves → Mdyn, density, temperature, ... (1h per source)

• Observe sources in HCN to trace dense regions of star-formation. (10h per source, 20 sources)

• Total: 12h per source, 170h for sample of 50 sources.

• Follow-up with ALMA:

• High resolution CO imaging to determine morphology (mergers?), derive rotation curves → Mdyn, density, temperature, ... (1h per source)

• Observe sources in HCN to trace dense regions of star-formation. (10h per source, 20 sources)

• Total: 12h per source, 170h for sample of 50 sources.

M51 Galaxy (Whirlpool, NGC5195)M51 Galaxy (Whirlpool, NGC5195)

Located at a distance of 37 million light-years from us, the famous M51 Galaxy (Sc type) was discovered in 1773 by Charles Messier.

Due to its orientation in space, it is seen "face-on".

Optical image of M51.

Left : Continuum Left : Continuum emission at 1.3 emission at 1.3 mm from the cold mm from the cold dust (<20K) contained dust (<20K) contained in the spiral arms of in the spiral arms of M51 as observedM51 as observedwith the 30m with the 30m telescope. telescope.

The pixel size in both images is 12 arc seconds. The continuum emission of cold dust closely follows the spiral pattern traced by the CO emission and correlates poorly with the emission from neutral hydrogen HI clouds. Similar results have been obtained by mapping the "edge-on" galaxy NGC 891, where the dust correlates well with the CO

emission up to a radius of 25 thousand light-years from the center of the galaxy.

Right: Map of the CO(2-1) emission from M51.

Obscured galaxyObscured galaxy formation: low redshift formation: low redshift (Meier & Turner 2004)(Meier & Turner 2004)

Obscured galaxyObscured galaxy formation: low redshift formation: low redshift (Meier & Turner 2004)(Meier & Turner 2004)

IC342 IC342

distance = 2 Mpcdistance = 2 Mpc MM_gas_gas = 4e7 M = 4e7 M_sun_sun

SFR = 0.1 SFR = 0.1 MM_sun_sun/yr/yr

Starburst age = Starburst age = 1e7 yrs1e7 yrs

IC342 IC342

distance = 2 Mpcdistance = 2 Mpc MM_gas_gas = 4e7 M = 4e7 M_sun_sun

SFR = 0.1 SFR = 0.1 MM_sun_sun/yr/yr

Starburst age = Starburst age = 1e7 yrs1e7 yrs

30” = 300pc

colors colors OPTICAL OPTICALGrey contours Grey contours CO(1-0) CO(1-0)White contours White contours mm mm continuumcontinuum

Nearby star forming Galaxies – Chemistry/Physics: IC342, Nearby star forming Galaxies – Chemistry/Physics: IC342, D=2MpcD=2Mpc

Nearby star forming Galaxies – Chemistry/Physics: IC342, Nearby star forming Galaxies – Chemistry/Physics: IC342, D=2MpcD=2Mpc

CO: all gas

HC3N: Dense

C2H: PDRs

ALMA: Image with GMC resolution (50pc) to 250 ALMA: Image with GMC resolution (50pc) to 250 MpcMpc

Rich clusters: Virgo = 16 Mpc, Coma = 100 Rich clusters: Virgo = 16 Mpc, Coma = 100 MpcMpc

ULIRGs: Arp 220 = 75 Mpc, Mrk 273 = 160 ULIRGs: Arp 220 = 75 Mpc, Mrk 273 = 160 MpcMpc

ALMA: Image with GMC resolution (50pc) to 250 ALMA: Image with GMC resolution (50pc) to 250 MpcMpc

Rich clusters: Virgo = 16 Mpc, Coma = 100 Rich clusters: Virgo = 16 Mpc, Coma = 100 MpcMpc

ULIRGs: Arp 220 = 75 Mpc, Mrk 273 = 160 ULIRGs: Arp 220 = 75 Mpc, Mrk 273 = 160 MpcMpc

300pc

Meier & Turner Meier & Turner 20042004

Nearby Gals II: Dynamics: Nearby Gals II: Dynamics: ‘feeding the nucleus’ – ‘feeding the nucleus’ – NGC6946, D=5.5MpcNGC6946, D=5.5Mpc

Nearby Gals II: Dynamics: Nearby Gals II: Dynamics: ‘feeding the nucleus’ – ‘feeding the nucleus’ – NGC6946, D=5.5MpcNGC6946, D=5.5Mpc

100 pc

PdBI 0.5” CO(2-1) PdBI 0.5” CO(2-1) - Gas Lanes along Bar - Gas Lanes along Bar - Streaming Motions Streaming Motions - Gas Disk w/ R <15pcGas Disk w/ R <15pc

ALMA: extend toALMA: extend toMrk 231 at 180 MpcMrk 231 at 180 MpcCygnus A at 240 MpcCygnus A at 240 Mpc

PdBI 0.5” CO(2-1) PdBI 0.5” CO(2-1) - Gas Lanes along Bar - Gas Lanes along Bar - Streaming Motions Streaming Motions - Gas Disk w/ R <15pcGas Disk w/ R <15pc

ALMA: extend toALMA: extend toMrk 231 at 180 MpcMrk 231 at 180 MpcCygnus A at 240 MpcCygnus A at 240 Mpc

Schinnerer et al., in prep.

– Detected sources not associated with cluster galaxies.– Associated with mJy radio sources (VLA)– Mostly dusty star forming galaxies at median redshift 2.5 - but also possible that heating sources are AGN

MAMBO survey of the cluster A2125 (Carilli et al. 2001) at 250 GHz

Disentangling Nuclear Starbursts Disentangling Nuclear Starbursts from AGNsfrom AGNs

Disentangling Nuclear Starbursts Disentangling Nuclear Starbursts from AGNsfrom AGNs

Optically identified submm detected sources (only three so far)Two of them have large molecular gas masses (seen through CO emission)

z = 2.81

z = 2.56

Dust continuumCO(3-2) emission

(Frayer & Scoville 1999)

AGN Type II

Starburst

0.1” res. ~1 kpc at z~1 0.01” res. ~1 kpc at z~3

Power of IR Classification:Edge-on Spiral NGC 5746

Power of IR Classification:Edge-on Spiral NGC 5746

Spitzer/IRAC3 -10 m

Opticalgri

2MASSJHK

Jarrett et al. 2003 (AJ, 125, 525)Frei al. 1996 (AJ, 111, 174)

Prominent dust lane in optical (and even near-IR) prevents unambiguous classificationIR images demonstrate class "Sab" with ringStar formation concentrated along ring and outside it

Prominent dust lane in optical (and even near-IR) prevents unambiguous classificationIR images demonstrate class "Sab" with ringStar formation concentrated along ring and outside it

NGC 5128 - Centaurus ANGC 5128 - Centaurus A NGC 5128 - Centaurus ANGC 5128 - Centaurus A

Visible imageVisible imageVisible imageVisible image

IRAC imageIRAC imageIRAC imageIRAC image

Keene et al. 2004Keene et al. 2004