UNM 29-Oct04

Galaxy-Halo Gas Kinematic Connection at 0.3 < z < 1

Collaborators:Chris Churchill (NMSU)Chuck Steidel (Caltech)Alice Shapley (Princeton)Wal Sargent (Caltech)Michael Murphy (IoA)

Glenn Kacprzak(New Mexico State University)

UNM 29-Oct04

How do the kinematics of the stellar component reflect that of the halokinematics?

Do absorption properties depend on the orientation of the host galaxy?

Is there a connection between absorption properties and host galaxy morphology?

Toward Establishing Kinematic Detailed Connections…

Our ultimate goal is to better understand how early epoch galaxy halos are built and sustained: Mg II absorbers provide excellent laboratory.

UNM 29-Oct04

Steidel et al. (2002)

Pilot Study of Mg II Galaxy Halo & Stellar Kinematics

In 4/4 strong systems, the Mg II gas co-rotates with the galaxy

In one weak system the absorption is at the systemic velocity of the galaxy.

RESULTS

Need a sample of galaxies that have a wide range of morphologies and orientations.

UNM 29-Oct04

Velocity km s-1

Mg II 2796 Absorber/Galaxy Selection

UNM 29-Oct04

z = 0.550 z = 0.551

z = 0.640 z = 0.661

z = 0.374

z = 0.525

z = 0.787

z = 0.346

z = 0.442

z = 0.553

z = 0.888

z = 0.729

z = 0.418

z = 0.494

z = 0.591

z = 0.298

z = 0.888

z = 0.472

z = 0.368z = 0.317

z = 0.437

z = 0.891z = 0.798

z = 0.656

z = 0.851

5”

5”

z = 0.534

z = 0.524

z = 0.312 z = 0.313

z = 0.393

z = 0.948

z = 0.430

z = 0.752

z = 0.383

z = 0.702

Quasar is oriented downward

UNM 29-Oct04

Simard et al. (2002)

NE

Galaxy Models: GIM2D

HST Galaxies

Model Images

Residual Images

UNM 29-Oct04

LuminosityImpact parameterDisk inclinationPA wrt QSOBulge to Total ratioBulge effective radiusDisk scale lengthHalf light radiusMorphological asymmetries

Toward Establishing Kinematic Detailed Connections…

Equivalent widthDoublet ratioVelocity spreadVelocity asymmetryNumber of cloudsTotal column density

Galaxy Properties Absorption Properties

UNM 29-Oct04

QSO

Velocity

Inte

nsi

ty

PA = 45o i = 90o PA = 45o i = 60o PA = 0o i = 90o PA = N/A i = 0o

cos(PA)sin(i) = 0.61 cos(PA)sin(i) = 1.0 cos(PA)sin(i) = 0.0

Testing a Simple Model of Orientation and Position Angle

UNM 29-Oct04

No Orientation Correlation!

More detailed models are needed

UNM 29-Oct04

Barred Spiral Structure!

GIM2D: Galaxy Asymmetry

HST Image Model Model Residual

UNM 29-Oct04

Asymmetry & Absorption Strength

Galaxy asymmetry and Impact parameter are both important factors in determining the absorption strength.

3.2σ correlation.

This suggests past minor mergers or interactions influence the quantity and/or velocity dispersion of halo gas.

UNM 29-Oct04

3C.336 Field Absorbers & Non-Absorbers

UNM 29-Oct04

Absorbers vs. Non-Absorbers within 25΄΄

Possible techniques for finding absorbers in a galaxy rich field.

We will obtain photo-z this summer.

UNM 29-Oct04

• Halo gas is “aware” of the kinematics of the galaxy (pilot study 5 galaxies).

• There are no clear trends between absorption strength and orientation of the galaxy. More detailed models are needed.

• Minor morphological perturbations are correlated to absorption strength. This may suggest that most Mg II absorption selected galaxies have had some previous minor interactions or harassments.

• Some indication that absorbers and non-absorbers may differ in their luminosity weighted morphological perturbations.

• Incorporate C IV and other ionization species into the analysis.

• Obtain redshifts of remaining candidates in order to increase sample size to over 50.

• Obtain rotation curves of the galaxy using Gemini and Keck.

• Obtain photometric redshifts of all HST fields to 200+kpc and fixed limiting absolute magnitude.

Conclusions …

Future …

UNM 29-Oct04

Forbidden Gas Lagging Halo

Ellison et al. (2003)

Swaters et al. (1997)Schaap et al. (2000)Sancisi et al. (2001)

Fraternali et al. (2002)

CAUTIONARY TAIL: A counter example!!

MC 1331+170; zabs=0.7446; Edge on spiral that does not align with disk kinematics! Because of the symmetric velocity splittings, this has been interpreted as superbubbles (Bond+ 2001; Ellison+ 2003).

UNM 29-Oct04 Observed spectra contain an admixture of both models

Asymmetric Blended Line Morphology

Symmetric Resolved Line Morphology

UNM 29-Oct04

Swaters et al. (1997)

Halo gas appears to rotate 25 to 100 km s-1 more slowly than the gas in the plane.     

 

Disk gas

Halo gas

• D = 9.5 Mpc• Neutral hydrogen map from WSRT• Presence of an H I halo extending up

to at least 5 kpc from the plane

21-cm Mapping of Rotations Curves in Lower Halos…