ifu observations of the high-z universe constraints on feedback from deep field observations with...

Download IFU observations of the high-z Universe Constraints on feedback from deep field observations with SAURON and VIMOS Joris Gerssen

Post on 12-Jan-2016




0 download

Embed Size (px)


  • IFU observations of the high-z UniverseConstraints on feedback from deep field observations with SAURON and VIMOS

    Joris Gerssen

  • OverviewUntil a decade ago only extreme objects were known in the distant universeSince then photometric redshift surveys and narrow band surveys identified ( at z ~2 to ~4) Lyman Break Galaxies Ly-alpha galaxiesObservational constraints on galaxy formation and evolutione.g. morphology, star formation history, luminosty functions, etc.

  • Among the drivers behind this advancement areThe 10m class telescopes and instrumentsHubble Space TelescopeTheoretical understanding of structure formation

    Integral Field Spectropscopy (IFS) is a recent development with great potential to further galaxy evolution studies

  • Integral Field Spectroscopy Data cube: f(x, y, lambda) VIMOS SINFONI MUSE SAURON PMAS Field-of-View few (tens) of arcsecSpectral resolution: R ~200 to ~2500Typical properties:

  • High-redshift science with IFUs(e.g. list of MUSE science drivers)

    Formation and evolution of galaxies:High-z Ly- emittersFeedbackLuminosity functions (PPAK, VIRUS)Reionization...

  • FeedbackA longstanding problem in galaxy formation is to understand how gas cools to form galaxies

    Discrepancy between observed baryon fraction (~8%) and predicted fraction (> 50% )

    To solve this cosmic cooling crisis the cooling of gas needs to be balanced by the injection of energy (SNe/AGN)

  • FeedbackGalactic outflows driven by AGN and/or SNeResolve discrepancy between observed and predicted baryon fractionTerminate star formationEnrich IGM

    NGC 6240 (ULIRG)M82 (starburst)

  • IFU Deep Field Observations

    Deep SAURON & VIMOS observations of blank skyBut in practice centered on QSOs/high-z galaxiesobserve extended Ly- halo emissionserendipitous detections

  • SAURON Deep FieldsThe SAURON IFU is optimized for the study of internal kinematics in early type galaxies

    DF observations of: SSA22a, SSA22b, HB89Redshift range 2.9 - 3.3 (4900 - 5400 Angstrom)Texp ~10 hours FoV: 33 x 41 arcsec, R ~ 1500

  • SSA22aSAURON observations: overviewSSA22b HB89 1738+350

  • SSA22b (z = 3.09) Wilman, Gerssen, Bower, Morris, Bacon, de Zeeuw & Davies (Nature, 14 July 2005)VolView rendering

  • Ly- distribution1.0 arcsec = 7.6 kpc

  • Line profilesEmission lines ~ 1000 km/s wideEmission peaks shift by a few 100 km/sAbsorption minima differ by at most a few tens of km/s

    Ly alpha is resonant scattered, naturally double peaked

    Yet, absorption by neutral gas is a more straighforward explanation

  • Model cartoon

  • SSA22b resultsAssuming shock velocities of several 100 km/s

    Shell travels ~100 kpc in a few 108yrShell can cool to ~104 K in this timeImplied by the Voigt profile b parameterRequired to be in photoionization equilibriumImplied shell mass of 1011 MKinetic energy of the shell ~1058 ergAbout 1060 erg available (IMF)Superwind model provides a consistent, and energetically feasible description

  • Comparison with SSA22aSSA22aKinematical structure more irregularLuminous sub-mm sourceSuggests that a similar outflow may have just begun

    Probe a wider range of galaxies:SCUBA galaxy (observed last year)Radio galaxy (observed one last week)LBG (a few hours last week)

  • SINFONI observations of SSA22bFoerster Schreiber et al. Constrain the stellar propertiesLink them to the superwindScheduled for P77 (B)

  • Serendipitous emittersThe correlation of Ly-alpha emitters with the distribution of intergalactic gas provides another route to observationally constrain feedback

    Based on Adelberger et al (2003) who find that the mean transmission increases close to a QSO This result is derived from 3 Ly- sources only

  • Mean IGM transmissionAdelberger et al. 2003Adelberger et al. 2005 z ~ 3 z ~ 2.5

  • Advantage of IFUsIFUs cover a smaller FOV then narrow band imaging, butIFUs are better matched to Ly-alpha line widthDo not require spectroscopic follow-upDirectly probe the volume around a central QSO

    Thus, IFUs should be more efficient than narrow band surveys

  • IFU observationsSearch the data cube for emittersUse the QSO spectrum to measure the gas distributionLikely require the UVES spectra Available: One SAURON data cube2 of 4 VIMOS IFU data cubes SAURON example: HB89 +1738+350

  • VIMOS 'QSO2'z = 3.92, Texp = 9 hoursLR mode

  • Search by eye for candidatesNeed to identify/apply an automated procedure

  • Detection algorithmsMatched kernel searchMany false detections

    IDL algorithm (van Breukelen & Jarvis 2005)FLEX: X-ray based technique (Braito et al. 2005)ELISE-3D: sextractor based (Foucaud 2005)

  • van Breukelen & Jarvis (MNRAS 2005)Similar data set: Radio galaxy at z = 2.9same instrumental set upsimilar exposure timeYet, they find more (14) and brighter Ly- emittersUsing an automated source finder

  • In progressA direct comparison with the van Breukelen resultsObtained their data from ESO archiveAnd reduced and analyzed it with our proceduresPreliminary results are in reasonably good agreementOur data appears somwhat more noisyFind their emitters and their new type-II quasar (Jarvis et al 2005)

  • Preliminary results

    Number density of Ly alpha emitters agrees with model predictions (fortuitous)The VIMOS fields contain 5 - 14 emittersModels (Deliou 2005) predict 9 in a similar volume

    IFUs are sensitive to at least a few 10E-18 erg/s/cm2

  • SummaryIFUs provide a uniquely powerful way to study the haloes around high redshift proto-galaxies

    Volumetric data are an efficient way to search for Ly-alpha galaxiesAn alternative method to constrain feedback

    IFUs are a very valuable new tool to study the formation and evolution of galaxies