Simulations and Observations for the LADUMA Survey - Natasha Maddox SKA Postdoctoral Fellow ACGC, University of Cape Town 2011 SA SKA Bursary ...

Simulations and Observations for the
         LADUMA Survey
                 Natasha Maddox
             SKA Postdoctoral Fellow
          ACGC, University of Cape Town
          2011 SA SKA Bursary Conference

Outline

•   The LADUMA Survey
•   Ancillary data
•   Simulations

LADUMA
•   Looking at the Distant Universe with the MeerKAT Array
•   Awarded 5000 hours of MeerKAT time for observations of
    a single pointing
•   Direct HI detections z≤0.6, stacked detections z≤1.2

LADUMA
•   Looking at the Distant Universe with the MeerKAT Array
•   Awarded 5000 hours of MeerKAT time for observations of
    a single pointing
•   Direct HI detections z≤0.6, stacked detections z≤1.2

      PIs: S.-L. Blyth (UCT), B.W. Holwerda (ESA), A.J. Baker (Rutgers)

        B. Bassett, M. Bershady, A. Bouchard, F.H. Briggs, B. Catinella, L. Chemin, S.
    Crawford, C. Cress, J. Darling, R. Davé, R. Deane, E. de Blok, E. Elson, A. Faltenbacher,
       B. Frank, E. Gawiser, T. Henning, I. Heywood, J. Hughes, M. Jarvis, R. Johnston,
            S. Kannappan, N. Katz, D. Kereš, H-R. Klöckner, R.C. Kraan-Korteweg,
        P. Lah, M. Lehnert, A. Leroy, N. Maddox, G. Meurer, M. Meyer, K. Moodley,
      R. Morganti, D. Obreschkow, S.-H. Oh, T. Oosterloo, D.J. Pisano, S. Ravindranath,
        S. Rawlings, E. Schinnerer, A. Schröder, K. Sheth, M. Smith, R. Somerville, R.
    Srianand, L. Staveley-Smith, I. Stewart, M. Vaccari, P. Väisänen, K.J. van der Heyden,
      W. van Driel, M. Verheijen, F. Walter, E. Wilcots, T. Williams, P. Woudt, M. Zwaan

LADUMA: Key Goals

LADUMA: Key Goals
•   To investigate the HI mass function in different
    environments to z≤0.6

                                     z≤0.06

                                   Martin et al 2010

LADUMA: Key Goals
•   To investigate the HI mass function in different
    environments to z≤0.6
•   To measure the evolution of ΩHI using HI
    emission to z≤1.2

LADUMA: Key Goals
•   To investigate the HI mass function in different
    environments to z≤0.6
•   To measure the evolution of ΩHI using HI
    emission to z≤1.2

                                          P Lah, Private Communication

LADUMA: Key Goals
•   To investigate the HI mass function in different
    environments to z≤0.6
•   To measure the evolution of ΩHI using HI
    emission to z≤1.2
•   To determine how galaxies’ HI masses depend
    on stellar/halo mass with redshi4

LADUMA: Key Goals
•   To investigate the HI mass function in different
    environments to z≤0.6
•   To measure the evolution of ΩHI using HI
    emission to z≤1.2
•   To determine how galaxies’ HI masses depend
    on stellar/halo mass with redshi4
•   To measure the evolution of the baryonic Tully-
    Fisher relation

LADUMA field:

•   Pointing centred on
    ECDF-S (dec=-27)
•   Significant multi-
    wavelength data       ECDF-S
                          0.3deg2
    already exist

LADUMA field:

•   Pointing centred on
    ECDF-S (dec=-27)
•   Significant multi-       z=0
                          0.9 deg2
    wavelength data       ECDF-S
                          0.3deg2
    already exist

LADUMA field:

•   Pointing centred on
                            z=1
    ECDF-S (dec=-27)      3.8 deg2

•   Significant multi-       z=0
                          0.9 deg2
    wavelength data       ECDF-S
                          0.3deg2
    already exist

LADUMA field:
                           z=1.2
                          4.5 deg2
•   Pointing centred on
                            z=1
    ECDF-S (dec=-27)      3.8 deg2

•   Significant multi-       z=0
                          0.9 deg2
    wavelength data       ECDF-S
                          0.3deg2
    already exist

LADUMA field:
                           z=1.2
                          4.5 deg2
•   Pointing centred on
                            z=1
    ECDF-S (dec=-27)      3.8 deg2

•   Significant multi-       z=0
                          0.9 deg2
    wavelength data       ECDF-S
                          0.3deg2
    already exist
•   Existing data help
    determine
    requirements

Ancillary Data:
•   Multi-band photometry and spectroscopy required
    over entire field of view

Ancillary Data:
•   Multi-band photometry and spectroscopy required
    over entire field of view
•   Accurate spectroscopic✳ redshi4s critical for
    success of LADUMA (especially at high redshi4)

Ancillary Data:
•   Multi-band photometry and spectroscopy required
    over entire field of view
•   Accurate spectroscopic✳ redshi4s critical for
    success of LADUMA (especially at high redshi4)
•   Observations started this semester so data will be
    in place for 2016

Ancillary Data:
•   Multi-band photometry and spectroscopy required
    over entire field of view
•   Accurate spectroscopic✳ redshi4s critical for
    success of LADUMA (especially at high redshi4)
•   Observations started this semester so data will be
    in place for 2016
•   ANU SkyMapper multi-band optical imaging
    already underway

Ancillary Data:
•   Multi-band photometry and spectroscopy required
    over entire field of view
•   Accurate spectroscopic✳ redshi4s critical for
    success of LADUMA (especially at high redshi4)
•   Observations started this semester so data will be
    in place for 2016
•   ANU SkyMapper multi-band optical imaging
    already underway
•   7.5 hours of Rutgers + South African time allocated
    with RSS MOS on SALT for Autumn 2011

LADUMA Simulations:

LADUMA Simulations:

•   Important to understand what we expect to
    observe

LADUMA Simulations:

•   Important to understand what we expect to
    observe
•   Help direct planning of both radio and ancillary
    observations

LADUMA Simulations:

•   Important to understand what we expect to
    observe
•   Help direct planning of both radio and ancillary
    observations
•   Assist so4ware development, pipeline algorithms,
    and analysis methods

LADUMA Simulations:

•   Important to understand what we expect to
    observe
•   Help direct planning of both radio and ancillary
    observations
•   Assist so4ware development, pipeline algorithms,
    and analysis methods
•   NOTE: This is a preliminary investigation, to be
    used in conjunction with other MeerKAT-specific
    simulations

S3: The SKA Simulated Skies
    http://s-cubed.physics.ox.ac.uk

•   Use the Millennium
    Simulation + semi-
    analytic models to
    construct a virtual
    Universe
•   “Observations” of this
    Universe can be made

                         Obreschkow et al. 2009b,
                         Obreschkow et al., 2009d

Strategy:

(1) Extract a volume from S3 that represents
 initial phase of LADUMA observations (zHI≤0.6)
(2) Construct “data cubes” using STools facility,
 setting beam size, noise level, channel width.
 (No continuum emission, interference, or other
 complicating factors associated with actual observations
 at this stage)

(3) Detect sources using Duchamp source finder
 (M. Whiting, ATNF CSIRO)

Simulation variables:

•   Channel width = 72kHz here for manageable cubes
•   Noise level = 33μJy per 72kHz channel for 1000h
    observation
•   Beam size and FoV increase with redshi4
•   Working on finding optimal source finder
    parameters

Preliminary Results

Preliminary Results
•   Number of galaxies in the simulation volume as
    a function of redshi4:

Preliminary Results
•   Number of galaxies in the simulation volume as
    a function of redshi4:

                        Min Freq               Min Freq
                        1000MHz                900MHz

Preliminary Results
•   Number of galaxies detected in the simulation
    volume as a function of redshi4:

Preliminary Results
•   Number of galaxies detected in the simulation
    volume as a function of redshi4:

HI Mass detections:
•   MHI of galaxies in the simulation volume as a
    function of redshi4:

HI Mass detections:
•   MHI of detected galaxies in the simulation volume
    as a function of redshi4:

Future work:
•   LADUMA all team meeting at UCT Jan 2012
•   Source finding workshop at UCT Jan 2012
     ➡   Find optimal parameters in Duchamp
         source finder (ideas welcome!)
•   Optimise observing strategy for final MeerKAT
    specifications
•   Keep collecting both multi-band imaging and
    spectroscopy covering entire field of view

Summary
•   LADUMA survey is making progress (no longer in
    purely planning stage)

Summary
•   LADUMA survey is making progress (no longer in
    purely planning stage)
•   Ancillary data collection is critical for success

Summary
•   LADUMA survey is making progress (no longer in
    purely planning stage)
•   Ancillary data collection is critical for success
•   Simulations (these and others) essential for fine-
    tuning observing strategy and understanding the
    results

Summary
•   LADUMA survey is making progress (no longer in
    purely planning stage)
•   Ancillary data collection is critical for success
•   Simulations (these and others) essential for fine-
    tuning observing strategy and understanding the
    results
                Dec
                      RA

                                                 z

Ancillary Data:

•   Match observing facilities
    to the task
                                  ECDF-S

                                 ~0.54 deg

Ancillary Data:

                                 RSS
                                 MOS
•   Match observing facilities
    to the task
                                        ECDF-S

                                       ~0.54 deg

Ancillary Data:

                                 RSS
                                 MOS
•   Match observing facilities
    to the task
                                        ECDF-S

                                       ~0.54 deg

Ancillary Data:

                                 RSS
                                 MOS
•   Match observing facilities
    to the task
•   Use smaller telescopes for          ECDF-S
    bright targets, use SALT
    for faint objects

                                       ~0.54 deg

Example RSS MOS mask: