A survey for DLA galaxieswith integral field spectroscopy

Lise Christensen ( Ph.D. student, AIP, Postdam)Collaborators: Sebastian Sanchez, Knud Jahnke,

Lutz Wisotski, Martin Roth

The survey

PurposeWhat types of galaxies host DLAs?Look for emission lines from the galaxies hosting DLAsDLA lines known from the literatureEmission properties and impact parameters

Main parts:

• Low redshift: Search for optical emission lines from known objects

• High redshift (z > 2): search for objects with Lyman- emission somewhere close to the QSO

PMAS facts

Observations are done with:

PMAS= Potsdam Multi Aperture Spectrophotometer

16*16 fibres connected to lens array (no loss between fibres)

8”*8” field of view ( in our setup)

3.5 m telescope at Calar Alto, Spain

IFS advantages:

Imaging and spectrosopy simultaneously

No slit-losses

Pointing less crucial

Spectral resolution independent on spatial sampling and seeing

Method

Visualisation – long slits

Visualisation – narrow bands - cubes

Movies….

Looping through a cube ofQ2233+131,Sub-DLA @ z =3.15

Candidate DLA galaxies

High redshift DLAs

13 DLAs included in the survey (+ 7 sub-DLAs) towards 9 QSOs

8 good candidates found – but only candidates

Line flux in the range 3-10*10-17erg cm-2 s-

1

Impact parameters from 1 - 4” (10 - 40 kpc)

Results; Line fluxes ; Velocities; Metallicities ; Impact parameters

Results; Line fluxes ; Velocities; Metallicities ; Impact parameters

Results; Line fluxes ; Velocities; Metallicities ; Impact parameters

Results; Line fluxes ; Velocities; Metallicities ; Impact parameters

Exponential fit

Scale length

kpc

kpc

ConclusionsFollow-up slit spectra needed

Impact parameters consistent with large disks

Fluxes rather large – Ly properties consistent with those of previously identified DLA galaxies

No preference for candidates from high metallicity DLAs

Integral field spectroscopy is suited for the project

With 8-m class telescopes identification of DLA galaxies will be trivial

Identifying emission lines

16 spectra

Emission from QSO

Emission line candidate

Results; Flux ; Velocities; Metallicities ; Impact parameters

Power-law fit : b/b*=(N(H)/N(H)*) b*= kpc, =0.220.18