C. Churchill (NMSU)D. Ceverino (NMSU)A. Klypin (NMSU) C. Steidel (Caltech)M. Murphy (Swinburne)N. Vogt (NMSU)

Glenn G. Kacprzak (NMSU / Swinburne)

Extended Halo Gas and Galaxy Kinematics At Intermediate Redshift

May 16th 2008Socorro, NM

Rots et al. 1990

How far in galactocentric distance does the kinematics of the gas couple to the angular momentum of the galaxy?

How well does the kinematics of the gas reflect the kinematics of the stellar galaxy?

Where is the galaxy halo-IGM interface?

Do we see dominate inflow and/or outflow signatures?

How important are stellar feedback energetics in regulating the sizes, geometries, dynamics, and multiphase ionization structures of galaxy halos?

Some Key Questions…

This Talk:

Results from the kinematic comparison of MgII absorption selected galaxies to their halo gas (0.3<z<1.0).

A similar preliminary kinematic study of galaxy/halo gas in cosmological simulations (as discussed by Ceverino and Churchill).

Galaxy/Halo Gas Kinematics For MgII Absorption Selected Galaxies

What is needed is a larger sample which represents a broad range of orientations with respect to the quasar line of sight

Sample: 5 edge-on MgII absorption selected galaxies

Steidel et al. (2002)

4 of the 5 showed the trend for the halo gas kinematics follows that of the galaxies

Halo gas rotation appears to dominate over infall and outflow

5”

10 Galaxy Spectra Obtained on Keck ESI

z = 0.313 z = 0.313 z = 0.417

z = 0.483

5”

z = 0.328

z = 1.017z = 0.787

z = 0.852

z = 0.494

• Only 6 edge-on galaxies have been observed up until now. The results hint that the halo gas co-rotates with the galaxy.

• Our goal is to explore different galaxy orientations with respect to the quasar line of sight as well as a full range of impact parameters.

Q0229+131 zgal= 0.4167 D= 38 kpc

Fig 4. Same as Fig 3. Note again the alignment of the rotation curve and MgII absorption.

10 Galaxy Rotation Curves Obtained with Keck/ESI

Q0454-220 zgal= 0.48382 D= 107 kpc

10 Galaxy Rotation Curves Obtained with Keck/ESI

Gas velocities at 107 kpc are consistent with that of the galaxy

Velocity (km/s)

Dlo

s (k

pc

)

Flu

x

Kacprzak et al. 2008b, in prep

•In all but one case, all the extended absorbing gas resides on one side of the systemic velocity of the galaxy.

•However, the a lagging halo model cannot reproduce the observed velocity spread in the gas.

i < 50 (face-on) i > 50 (edge-on)

Kacprzak et al. in prep

Possible Orientation Effect?

Mock QSO Spectra

170 kpc

Dlo

s (k

pc)

Consistent with Disk-like KinematicsInconsistent with Disk-like Kinematics

Planar Filament Inflow

Foreground Satellites

Outflow Via Winds & SN

Filament Inflow

Multiple Complex Mechanisms Contributing to halo Kinematics!

Galaxy Inclination Effects in MgII Absorption

Edge-on

Face-on

i=45

Absorption Velocity offset (km/s)

Absorption Velocity offset (km/s)

170 kpc

Mock QSO Spectra

N(MgII) > 12

3D View of Absorbing Gas Cells

N(MgII) > 12 N(CIV) > 12

3D View of Absorbing Gas Cells

N(MgII) > 12 N(CIV) > 12 N(OIV) > 12

3D View of Absorbing Gas Cells

N(MgII) > 12 N(CIV) > 12 N(OIV) > 12

Velocity Distribution of Gas Cells

Radial Vel (km/s)

Nor

mal

ized

#

MgII is primarily infalling material with a small fraction of has zero radial velocity.

CIV and OVI peak exhibit lower velocity inflow.

MgII and CIV/OVI are probing different structures and kinematic driving mechanisms in the halo

N(MgII) > 12 N(CIV) > 12 N(OIV) > 12

LOS 1

Halo Gas Kinematics LOS 1

MgII/CIV Halo Gas Kinematics

In Conclusion

Kinematics:

•Halo gas is almost always to one side of the systemic velocity of the galaxy.

•The halo gas appears to be kinematically coupled to the galaxy, however, disk-like halo rotation models do not adequately reproduce the absorption velocities.

•Simulations indicate that multiple energetic mechanisms give rise to the observed halo gas kinematics.

•Simulations show that MgII gas arises in clouds and streams of infalling and outflowing material generated by minor mergers and satellite harassment.

•Possible galaxy orientation effects seen in MgII absorption

•CIV and OVI are more diffuse in the halo, different probes of energetics.