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EMU: Evolutionary Map of the Universe Ray Norris 13 September 2011.

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Presentation on theme: "EMU: Evolutionary Map of the Universe Ray Norris 13 September 2011."— Presentation transcript:

1 EMU: Evolutionary Map of the Universe Ray Norris 13 September 2011

2 Goals of this meeting: update people on whats happening get input into future directions tap into local expertise hope to get plenty of round-table discussion as well as presentations if you are not yet part of EMU and you would like to be, please ask me!

3 ASKAP=Australian SKA Pathfinder A$170M (=120m) project now under construction in Western Australia Completion early *12m antennas Antennas have a 92-pixel phased array feed (PAF) 30 sq. deg FOV!

4 ASKAP Design Specifications Number of antennas36 (630 baselines) Antenna diameter12 m (3 axis) Maximum baseline6 km Cont. Angular resolution10 arcsec Sensitivity65 m²/K Frequency range700 – 1800 MHz Focal plane phased array188 elements (92 dual pol) Field of view30 deg² Processed bandwidth300 MHz Number of channels16 384

5 Current major 20cm surveys NVSS 75% of sky rms=450μJy EMU 75% of sky rms=10μJy EMU+WODAN 100% of sky Increasing sensitivity Increasing area

6 Perth Sydney Brisbane Melbourne Adelaide Darwin Alice Springs WESTERN AUSTRALIA NORTHERN TERRITORY SOUTH AUSTRALIA QUEENSLAND NEW SOUTH WALES VICTORIA TASMANIA Hobart ACTCanberra Murchison Radio Astronomy Observatory INDIAN OCEAN CORAL SEA SOUTHERN OCEAN

7 Perth Sydney Brisbane Melbourne Adelaide Darwin Alice Springs WESTERN AUSTRALIA NORTHERN TERRITORY SOUTH AUSTRALIA QUEENSLAND NEW SOUTH WALES VICTORIA TASMANIA Hobart ACTCanberra Murchison Radio Astronomy Observatory INDIAN OCEAN CORAL SEA SOUTHERN OCEAN Australia – WA – Midwest – Murchison

8 Perth Sydney Brisbane Melbourne Adelaide Darwin Alice Springs WESTERN AUSTRALIA NORTHERN TERRITORY SOUTH AUSTRALIA QUEENSLAND NEW SOUTH WALES VICTORIA TASMANIA Hobart ACTCanberra Murchison Radio Astronomy Observatory INDIAN OCEAN CORAL SEA SOUTHERN OCEAN Murchison gazetted towns: 0 population: up to 160 Geraldton

9 Perth Sydney Brisbane Melbourne Adelaide Darwin Alice Springs WESTERN AUSTRALIA NORTHERN TERRITORY SOUTH AUSTRALIA QUEENSLAND NEW SOUTH WALES VICTORIA TASMANIA Hobart ACTCanberra Murchison Radio Astronomy Observatory INDIAN OCEAN CORAL SEA SOUTHERN OCEAN Murchison gazetted towns: 0 population: up to 160 Geraldton

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12 Configuration and uv-coverage Antenna configuration 2-km core with 30 antennas 6 antennas further out 50° 10°

13 Gupta et al. 2008, ATNF ASKAP Memo Antenna Array Configuration Spectral Line: Inner 30 dishes only, resolution 30 arcsec (all at 1.4 GHz) Continuum: uniform weighting: resolution 10 arcsec Natural weighting: resolution 20 arcsec

14 Sensitivity of EMU to a 1 Mpc cluster halo:

15 Antennas Antennas built by CETC54 (China) Delivered and assembled on site Antenna 1 delivered late 2009

16 Antennas Antennas 2-6

17 ASKAP – PAF: 188 element unit

18 First 2 full-size ASKAP PAFs

19 Data Transport Direct burial of 300km fibre (Boolardy-Geraldton) started Oct 2010 Now complete (June 2011) Includes 3 repeater huts NBN network Perth-Geraldton also completed June 2011

20 BETA: Boolardy Engineering Test Array BETA construction on schedule

21 ASKAP current status Construction is on schedule 36 antennas in place by end of 2011 fibre all in place eVLBI to NZ conducted in July 2011 Parkes PAF is performing well BETA will be available end of 2011/early 2012

22 PAF performance Performing very well Tsys < 50K at low freq Tsys ~ 100K at high freq can be fixed

23 End of 2011: 36 antennas on site all hardware on site for 6-antenna BETA array Early 2012: BETA commissioning starts ASKAP Design enhancement Use experience from Mki PAF to develop MkII PAF Better PAFs at lower cost March 2013: Science-ready ASKAP available minimum of 12 antennas equipped with PAFs 2013… Antennas continue to be equipped with PAFs as funding permits A good target would be: All antennas equipped with upgraded PAFs by Dec 2013 ASKAP – Possible schedule

24 The Science 38 proposals submitted to ASKAP 2 selected as being highest priority 8 others also supported EMU all-sky continuum (PI Norris) WALLABY all-sky HI (PI Koribalski & Staveley-Smith) COAST pulsars etc CRAFT fast variability DINGO deep HI FLASH HI absorption GASKAP Galactic POSSUM polarisation VAST slow variability VLBI

25 Deep radio image of 75% of the sky (to declination +30°) Frequency range: MHz 40 x deeper than NVSS 10 μJy rms across the sky 5 x better resolution than NVSS (10 arcsec) Better sensitivity to extended structures than NVSS Will detect and image ~70 million galaxies at 20cm All data to be processed in pipeline Images, catalogues, cross-IDs, to be placed in public domain Survey starts 2013 Total integration time: ~1.5 years ?

26 Complementary radio surveys Westerbork-WODAN using Apertif PAF on Westerbork telescope will achieve similar sensitivity to EMU will observe northern quarter of sky (δ>+30°) well-matched to EMU LOFAR continuum surveys lower frequency covering Northern half(?) of sky valuable because yields spectral index Meerkat-MIGHTEE Potentially deeper over smaller area, but will be limited by confusion until Meerkat Phase II (2016?)

27 ATLAS=Australia Telescope Large Area Survey Slide courtesy of Minnie Mao

28 The role of ATLAS as a testbed for EMU ATLAS has the same rms sensitivity (10uJy) as EMU has the same resolution (10 arcsec) as EMU covers (only!) 7 sq. deg. has (2000 ) galaxies Were using ATLAS to test many aspects of EMU Imaging (dynamic range, weighting) Source extraction Cross-identification Source database and VO server Science!

29 Science Goals

30 Redshift distribution of EMU sources Based on SKADS (Wilman et al.2006)

31 Evolution of SF from z=2 to the present day, using a wavelength unbiased by dust or molecular emission. Evolution of massive black holes and understand their relationship to star-formation. Explore the large-scale structure and cosmological parameters of the Universe. E.g, Independent measurement of dark energy evolution Explore an uncharted region of observational parameter space almost certainly finding new classes of object. Explore Diffuse low-surface-brightness radio objects Generate an Atlas of the Galactic Plane Create a legacy for surveys at all wavelengths (Herschel, JWST, ALMA, etc) Science Goals

32 To trace the evolution of the dominant star-forming galaxies from z=5 to the present day, using a wavelength unbiased by dust or molecular emission. Science Goal 1:

33 SFR measurable (5σ) by EMU Arp220 z=2 M82 z=0.4 Milky Way z=0.1 With 45 million SF galaxies, can stack to measure SFR to much higher z HyperLIRG z=4 Measured radio SFR does not need any extinction correction

34 Region occupied by unidentified sub-mJy radio sources? (From Hopkins et al 2004, Barger et al 2000) What dominates SFR at each z? Present Day Redshift Time since Big Bang (Billions of years)

35 Science Goal 2: To trace the evolution of massive black holes throughout the history of the Universe, and understand their relationship to star-formation.

36 EMU will detect 25 million AGN Other questions: How much early activity is obscured from optical views? Can we use trace the evolution of MBH with z? When did the first MBH form? We will detect rare objects, such as high-z AGN composite AGN/SF galaxies galaxies in a brief transition phase from quasar-mode to radio-mode accretion. Norris et al. 2008, arXiv: S 20cm = 9mJy z = L 20cm = 4 x WHz -1

37 F (ULIRG with L= L o ) Merger of two cool spirals: SB just turned on - AGN just turned on radio jets already at full luminosity, boring out through the dust/gas Almost no sign of this at optica/IR wavelengths see Norris et al. arXiv: kpc 1 kpc P= W/Hz z=0.327

38 z=0.22. From Mao et al 2010,MNRAS, in press. Radio surveys are unbiased by dust & sky lines How similar are the cosmic webs of AGNs and SF galaxies? Did they have a common origin? We can use head-tail galaxies as probes of clustering to high z. We should detect Integrated Sachs-Wolfe (ISW) effect directly, so testing the scale of Dark Energy at z > 1 Science Goal 3: To use the distribution of radio sources to explore the large-scale structure and cosmological parameters of the Universe.

39 Integrated Sachs-Wolfe Effect From ~10°

40 Science Goal 3: Cosmoology and Fundamental Physics EMU (70 million galaxies) has fewer objects than DES (300 million) but samples a larger volume => complementary tests EMU

41 Dark Energy See Raccanelli et al. ArXiv Current error ellipse is based on Amanullah et al., 2010, ApJ, 716, 712, plus Planck data

42 Modified Gravity See Raccanelli et al. ArXiv

43 6.1 mJy at 20 cm < 5 µJy at 3.6µm Norris et al 2007, MNRAS, 378, 1434; Middelberg et al 2008, AJ, 135, 1276; Garn & Alexander, 2008, MNRAS,391,1000; Huynh et al.,2010, ApJ, 710, 698; Norris et al. 2011, ApJ, in press Science Goal 4: To explore an uncharted region of observational parameter space, almost certainly finding new classes of object.

44 SERVS=>1400 hours on Spitzer 3.6 μm median stacked image Median of 39 images Flux density = μJy. Pixel size = 0.6 arcsec. SERVS Warm Spitzer observations of IFRS 3.6 μm Flux density = μJy. SERVS=>1400 hours on Spitzer Median of μm images Norris et al. 2011, ApJ, in press.

45 What is the density of new discoveries in parameter space? ATLAS pushed the boundaries by only a factor of a few, yet discovered two new classes of objects (PRONGS, IFRS). What happens when we push the boundary by a factor of 40? Limit of conventional radio-telescopes SKA pathfinders

46 New WG: Discovering the Unexpected (WTF: Widefield ouTlier Finder) Instead of hoping to stumble across new types of object, we will systematically mine the EMU database, discarding objects that already fit known classes of object based on their: morphology spectral index polarisation SED in optical/IR etc Objects that remain will be either processing artefacts (important for quality control) statistical outliers of known classes of object (interesting!) New classes of object (WTF)

47 Science goal 6: Produce the most complete catalogue of the Galactic Plane to date. Much deeper and higher res than any other survey: CGPS: arcmin, few mJy, 73° of Northern plane SGPS: arcmin, 35 mJy, most of S plane MAGPIS: 6 arcsec, 1-2 mJy, 27° of N plane EMU: 10 arcsec, down to 50 μJy, most of plane all of plane when linked to WODAN Build a complete census (and possibly discover new types of): all phases of HII region evolution the most compact and youngest supernova remnants radio-emitting Planetary Nebulae to constrain galactic density and formation rate Helfand et al 2006, AJ 131, 2525.

48 Science goal 7: Radio stars HR diagram for 420 radio stars (Gudel, 2002 ) Goals Increase # of known radio stars by Discover new types and define typical populations (unbiased) Identify trends and correlations current samples too small Algol: Mutel et al 2009 Understand stellar magnetic activity Understand coherent emission mechanisms

49 New EMU leadership structure Ray Norris Project Leader Ray Norris Project Leader Andrew Hopkins Project Scientist Andrew Hopkins Project Scientist Ilana Feain Project Scientist Ilana Feain Project Scientist Nick Seymour Project Scientist Nick Seymour Project Scientist Science Working Groups Science Working Groups Design Study Working Groups

50 Observing Strategy (Shea Brown) Commissioning, BETA, Observing Process (Ilana Feain) Simulations (Emil Lenc) Data processing Pipeline (Tom Franzen) Compact Source Extraction (Andrew Hopkins) Extended Source Extraction (Tom Franzen) Quality Control (Lisa Harvey Smith) Automated cross-IDs (Loretta Dunne) Galaxy Zoo Cross-IDs (Julie Banfield) Data Requirements (Ray Norris) Data Access and VO (Minh Huynh) Redshifts (Nick Seymour) WTF (Ray Norris)

51 EMU Roadmap Proposed changes to design study WGs: more, smaller, groups WG chairs to lead their WG actively EMU memo series Progress will be marked by milestones Major goals: written reports/papers Management team will regularly review progress of WG

52 Science Working Groups Currently unchanged: Evolution of Galaxies (Nick Seymour) Cosmology (Matt Jarvis/Shea Brown) Clusters (Melanie Johnston-Hollitt) Galactic Plane (Mark Thompson) Radio Stars (Gracia Umana) Diffuse Low Surface Brightness objects (Shea Brown) Stacking (Jose Afonso) Terminated: Simulated Radio Sky (=> simulations) Application to existing data (=> ATLAS) Collaboration with other SKA Pathfinders (=> SPARCS)

53 Science WGs Specific requests to science WGs Each WG to produce (at least) a paper/report on the science that will be done with EMU WG chairs need to involve members, not do things single-handedly!

54 Redshifts WG (WG chair Nick Seymour) Few of our 70 million galaxies will have spectroscopic redshifts Not enough photometry for good photometric redshifts BUT Have upto 9-band photometry for ~50% of EMU sources SkyMapper, SDSS, VHS, WISE Also have radio data that can constrain algorithm polarisation, spectral index, morphology. radio/Kband ratio, FRC Expect to be able to produce rough statistical redshifts for most sources if we have a good training set Use ATLAS COSMOS sources to train algorithms Proposing large spectroscopy programs on all ATLAS sources Experimenting with different algorithms Expect to classify in z bins: (e.g.) 0-0.5, 0.5-1, 1-2, 2-4, 4-8

55 Fraction of EMU sources detected at optical/IR

56 Solution: statistical redshifts Photometric redshifts are poor-mans spectroscopic redshifts Statistical redshifts are poor-mans photometric redshifts. Useful if you want to know the statistical properties of a sample. E.g. median z of EMU is 1.1 select polarised sources=> median z = 1.9 select steep-spectrum polarised source => median z =2+(?) Radio/MIR ratio also correlates with z, so even a K-band non- detection is valauble

57 EMU Survey Design Paper (PASA, in press,

58 Western Australia


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