Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Extra-planar gas at low and high redshifts

Extra-planar gas at low and high redshifts

Filippo FraternaliDepartment of Astronomy, University of Bologna, Italy

Filippo FraternaliDepartment of Astronomy, University of Bologna, Italy

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Extra-planar gas now and then

• Gaseous halos in edge-on galaxies and in galaxies at intermediate inclinations

• Are they observable at high-z?

• Star Formation and Gas Accretion History

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Extra-planar gas in edge-on galaxies

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

NGC 891: HI observations

Total Mass of the HI haloMHI ~1.2 x 109 M

~30% MHItot

> 200 hrs with the WSRT

Sancisi et al. 2008, A&ARv

Oosterloo, Fraternali, Sancisi 2007

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Artificial data-cubes

NGC 891 and models

HI Channel maps

Thin disk

Halo gas

VSys

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Models with lagging halo

NGC 891 and models

HI Channel maps

Thin disk

Halo gas

VSys

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

NGC891 at high redshifts

z = 0.5• Spatial resolution (seeing) 0”.6 ~ 3.6 kpc• Spectral resolution () ~ 10 km s-1

• No SB/flux corretion

1.5<z<2.5 • Spatial resolution (seeing) 0”.6 ~ 5 kpc• Spectral resolution () ~ 40 km s-1

• No SB/flux corretion

(VLT - FLAMES, O[II])

(VLT - SINFONI, H)

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

NGC891 at high redshiftz = 0.5 - FLAMES

Local

z = 2 - SINFONI

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Data cubes

QuickTime™ and aNone decompressor

are needed to see this picture.

QuickTime™ and aNone decompressor

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QuickTime™ and aNone decompressor

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z = 0.5 - FLAMES z = 2 - SINFONI

Halo features observable at high-z

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Rotation curves of edge-ons

To observer

Line of nodes Vsys

VROT

Line profile

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Rotational Gradient

Fraternali et al. 2005, ASPCvrot~15 km s-1 kpc-1

NGC 891

Strong rotational gradient with z

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Recovering rotation curvesz = 0.5 - FLAMES z = 2 - SINFONI

Disk rotation curve Disk rotation curve

Original dataHigh-z

At 5 kpc above the plane

Kinematics can be studied at high z!

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Extra-planar gas in inclined galaxies

Optical Neutral gas (VLA)

Same scale!Fraternali et al. 2002, ApJ

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

NGC 2403: halo gas

Halo gas

150 km/s

Fraternali, Oosterloo, Sancisi & van Moorsel 2001

Halo gas

Total Mass of the HI haloMHI ~3 x 108 M

~10% MHItot

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Data cubes

QuickTime™ and aNone decompressor

are needed to see this picture.

QuickTime™ and aNone decompressor

are needed to see this picture.

QuickTime™ and aNone decompressor

are needed to see this picture.

Beards are difficult to observe at high-z

z = 2 - SINFONI

z = 0.5 - FLAMES

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Velocity fieldsz = 0.5 - FLAMES z = 2 - SINFONI

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Recovering N2403 rotation curve

z = 0.5 - FLAMES z = 2 - SINFONI

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Velocity dispersion fieldsz = 0.5 - FLAMES z = 2 - SINFONI

Only resolution effects!

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Gas accretion history

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Star formation history

Hippelein et al. 2003Panter et al. 2006

Cignoni et al. 2008

SFH in the Milky Way

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Gas accretion history

Keres et al. 2005

• It should follow SFR

• Cold or prone to cool

• Some other observable effect?

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Accretion: high velocity gasNGC891 Filament Counter-rotating

clouds 580 km/s

Energy needed 1054-55

erg

15 kpc

Forbidden in a fountain

Accretion ~ 2 x 107

M/108yr ~ 0.2 M yr-1

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Accretion: High Velocity Clouds

Wakker 2007; Wakker & Van Woerden 1997; Tripp et al. 2003

Low metallicityZ=0.15 solar

Low metallicityZ=0.1-0.4 solar

HVCs masses ~< 107 M

accretion rate ~ 0.2 M/yr Most of the

accretion is hidden

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Minor mergers?

Global accretion rates ~ 0.2 MO/yr

Detected in ~25% of galaxies

Masses ~ 1-10 x 108 MO

Life time ~ 1-2 dyn time

Sancisi et al. 2008, A&ARv

Most of the accretion is hidden

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Gas dynamics in a pure fountain

Fountain gas has too high angular momentum

Fraternali & Binney, 2006, 2008See also Heald et al. 2007

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Fountain + Accretion in NGC891

Best-fit Accretion Rate ~ 3 Moyr-1

Compare to SFR ~ 4 Moyr-1

NGC891

Halo gas: ~90% from fountain ~10% accreted

Fountain must sweep up ambient gas at the rate ~ SFR

Filippo Fraternali (Bologna University)

3D - Munich - 12/06/08

Extra-planar gas at low and high z

Conclusions

2. Halos in edge-on galaxies can be studied at high-z, beards not clear

3. Gaseous halos are the key to study gas accretion

1. Local galaxies are surrounded by massive gaseous haloes with complex structure