Presentation on theme: "EMU: Evolutionary Map of the Universe"— Presentation transcript:
1 EMU: Evolutionary Map of the Universe Ray Norris13 September 2011
2 Goals of this meeting: update people on what’s happening get input into future directionstap into local expertisehope to get plenty of round-table discussion as well as presentationsif 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 AustraliaCompletion early 201336*12m antennasAntennas have a 92-pixel phased array feed (PAF)30 sq. deg FOV!
4 ASKAP Design Specifications Number of antennas 36 (630 baselines)Antenna diameter 12 m (3 axis)Maximum baseline 6 kmCont. Angular resolution 10 arcsecSensitivity 65 m²/KFrequency range 700 – 1800 MHzFocal plane phased array 188 elements (92 dual pol)Field of view 30 deg²Processed bandwidth 300 MHzNumber of channels
5 Current major 20cm surveys NVSS75% of skyrms=450μJyEMUrms=10μJyEMU+WODAN100% of skyIncreasing areaIncreasing sensitivity
6 PerthSydneyBrisbaneMelbourneAdelaideDarwinAlice SpringsWESTERN AUSTRALIANORTHERN TERRITORYSOUTH AUSTRALIAQUEENSLANDNEW SOUTH WALESVICTORIATASMANIAHobartACTCanberraMurchison Radio Astronomy ObservatoryINDIANOCEANCORALSEASOUTHERN OCEAN
7 Australia – WA – Midwest – Murchison PerthSydneyBrisbaneMelbourneAdelaideDarwinAlice SpringsWESTERN AUSTRALIANORTHERN TERRITORYSOUTH AUSTRALIAQUEENSLANDNEW SOUTH WALESVICTORIATASMANIAHobartACTCanberraMurchison Radio Astronomy ObservatoryINDIANOCEANCORALSEASOUTHERN OCEANGeraldton
8 Murchison gazetted towns: 0 Geraldton population: “up to 160” Perth SydneyBrisbaneMelbourneAdelaideDarwinAlice SpringsWESTERN AUSTRALIANORTHERN TERRITORYSOUTH AUSTRALIAQUEENSLANDNEW SOUTH WALESVICTORIATASMANIAHobartACTCanberraMurchison Radio Astronomy ObservatoryINDIANOCEANCORALSEASOUTHERN OCEANgazetted towns: 0population: “up to 160”Geraldton
9 Murchison Geraldton gazetted towns: 0 population: “up to 160” Perth SydneyBrisbaneMelbourneAdelaideDarwinAlice SpringsWESTERN AUSTRALIANORTHERN TERRITORYSOUTH AUSTRALIAQUEENSLANDNEW SOUTH WALESVICTORIATASMANIAHobartACTCanberraMurchison Radio Astronomy ObservatoryINDIANOCEANCORALSEASOUTHERN OCEANgazetted towns: 0population: “up to 160”Geraldton
17 ASKAP – PAF: 188 element unit The array is a complementary screen sitting above a groundplane with differential feed points at the groundplane between where the diamonds corners almost meet. The sensitivity of this array has been calculated for ASKAP  which has prime focus 12m dishes with an F/D of 0.5.
19 Data TransportDirect burial of 300km fibre (Boolardy-Geraldton) started Oct 2010Now complete (June 2011)Includes 3 repeater hutsNBN 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 2011fibre all in placeeVLBI to NZ conducted in July 2011Parkes PAF is performing wellBETA will be available end of 2011/early 2012
22 PAF performance Performing very well Tsys < 50K at low freq Tsys ~ 100K at high freqcan be fixed
23 ASKAP – Possible schedule End of 2011:36 antennas on siteall hardware on site for 6-antenna BETA arrayEarly 2012: BETA commissioning startsASKAP Design enhancementUse experience from Mki PAF to develop MkII PAFBetter PAFs at lower costMarch 2013: Science-ready ASKAP availableminimum of 12 antennas equipped with PAFs2013… Antennas continue to be equipped with PAFs as funding permitsA good target would be:All antennas equipped with upgraded PAFs by Dec 2013
24 The Science 38 proposals submitted to ASKAP 2 selected as being highest priority8 others also supportedEMU all-sky continuum (PI Norris)WALLABY all-sky HI (PI Koribalski & Staveley-Smith)COAST pulsars etcCRAFT fast variabilityDINGO deep HIFLASH HI absorptionGASKAP GalacticPOSSUM polarisationVAST slow variabilityVLBI
25 Deep radio image of 75% of the sky (to declination +30°) Frequency range: MHz40 x deeper than NVSS10 μJy rms across the sky5 x better resolution than NVSS (10 arcsec)Better sensitivity to extended structures than NVSSWill detect and image ~70 million galaxies at 20cmAll data to be processed in pipelineImages, catalogues, cross-IDs, to be placed in public domainSurvey starts 2013Total integration time: ~1.5 years ?
26 Complementary radio surveys Westerbork-WODANusing Apertif PAF on Westerbork telescopewill achieve similar sensitivity to EMUwill observe northern quarter of sky (δ>+30°)well-matched to EMULOFAR continuum surveyslower frequencycovering Northern half(?) of skyvaluable because yields spectral indexMeerkat-MIGHTEEPotentially 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 has the same rms sensitivity (10uJy) as EMUhas the same resolution (10 arcsec) as EMUcovers (only!) 7 sq. deg.has (2000) galaxiesWe’re using ATLAS to test many aspects of EMUImaging (dynamic range, weighting)Source extractionCross-identificationSource database and VO serverScience!
29 How did galaxies form and evolve? Science Goals
30 Redshift distribution of EMU sources Based on SKADS (Wilman et al.2006)
31 Science Goals Evolution of SF from z=2 to the present day, using a wavelength unbiased by dust or molecular emission.Evolution of massive black holesand understand their relationship to star-formation.Explore the large-scale structure and cosmological parameters of the Universe.E.g, Independent measurement of dark energy evolutionExplore an uncharted region of observational parameter spacealmost certainly finding new classes of object.Explore Diffuse low-surface-brightness radio objectsGenerate an Atlas of the Galactic PlaneCreate a legacy for surveys at all wavelengths (Herschel, JWST, ALMA, etc)
32 Science Goal 1: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.
33 SFR measurable (5σ) by EMU HyperLIRGz=4Arp220z=2Measured radio SFR does not need any extinction correctionM82z=0.4Milky Wayz=0.1With 45 million SF galaxies, can stack to measure SFR to much higher z
34 Region occupied by unidentified sub-mJy radio sources? RedshiftRegion occupied by unidentified sub-mJy radio sources?What dominates SFR at each z?(From Hopkins et al 2004, Barger et al 2000)Time since Big Bang (Billions of years)Present Day
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 We will detect rare objects, such ashigh-z AGNcomposite AGN/SF galaxiesgalaxies in a brief transition phase from quasar-mode to radio-mode accretion.Norris et al. 2008, arXiv:S20cm= 9mJyz = 0.932L20cm= 4 x 1025 WHz-1Other 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?
37 F00183-7111 (ULIRG with L=9.1012 Lo) P=6.1025 W/Hz z=0.327 1 kpc20kpcz=0.327P= W/HzMerger of two cool spirals:SB just turned on - AGN just turned onradio jets already at full luminosity, boring out through the dust/gasAlmost no sign of this at optica/IR wavelengthssee Norris et al. arXiv:
38 Science Goal 3: To use the distribution of radio sources to explore the large-scale structure and cosmological parameters of the Universe.Radio surveys are unbiased by dust & sky linesHow 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 > 1z=0.22. From Mao et al 2010,MNRAS, in press.
40 Science Goal 3: Cosmoology and Fundamental Physics EMUEMU (70 million galaxies) has fewer objects than DES (300 million) but samples a larger volume=> complementary tests
41 Dark Energy Current error ellipse Current best value Standard ΛCDM EMU error ellipseSee Raccanelli et al. ArXiv“Current error ellipse” is based on Amanullah et al., 2010, ApJ, 716, 712, plus Planck data
42 Modified Gravity Current error ellipse Current best value Standard GR EMU error ellipseSee Raccanelli et al. ArXiv
43 Science Goal 4: To explore an uncharted region of observational parameter space, almost certainly finding new classes of object.6.1 mJy at 20 cm< 5 µJy at 3.6µmNorris 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
44 SERVS Warm Spitzer observations of IFRS 3.6 μm Flux density = μJy.SERVS=>1400 hours on Spitzer3.6 μm median stacked imageMedian of 39 imagesFlux density = μJy.Pixel size = 0.6 arcsec.SERVS=>1400 hours on SpitzerMedian of μm imagesNorris et al. 2011, ApJ, in press.
45 What is the density of new discoveries in parameter space? Limit of conventional radio-telescopesSKA pathfindersATLAS 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?
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:morphologyspectral indexpolarisationSED in optical/IRetcObjects that remain will be eitherprocessing 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 planeSGPS: arcmin, 35 mJy, most of S planeMAGPIS: 6 arcsec, 1-2 mJy, 27° of N planeEMU: 10 arcsec, down to 50 μJy, most of planeall of plane when linked to WODANBuild a complete census (and possibly discover new types of):all phases of HII region evolutionthe most compact and youngest supernova remnantsradio-emitting Planetary Nebulae to constrain galactic density and formation rateHelfand et al 2006, AJ 131, 2525.
48 Science goal 7: Radio stars HR diagram for 420 radio stars (Gudel, 2002)GoalsIncrease # of known radio stars byDiscover new types and define typical populations (unbiased)Identify trends and correlationscurrent samples too smallUnderstand stellar magnetic activityUnderstand coherent emission mechanismsAlgol: Mutel et al 2009
49 New EMU leadership structure Ray NorrisProject LeaderAndrew HopkinsProject ScientistIlana FeainProject ScientistNick SeymourProject ScientistDesign Study Working GroupsScienceWorking Groups
50 Design Study Working Groups 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, groupsWG chairs to lead their WG activelyEMU memo seriesProgress will be marked by milestonesMajor goals: written reports/papersManagement 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 EMUWG 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 redshiftsNot enough photometry for good photometric redshiftsBUTHave upto 9-band photometry for ~50% of EMU sourcesSkyMapper, SDSS, VHS, WISEAlso have radio data that can constrain algorithmpolarisation, spectral index, morphology. radio/Kband ratio, FRCExpect to be able to produce rough “statistical redshifts” for most sources if we have a good training setUse ATLAS COSMOS sources to train algorithmsProposing large spectroscopy programs on all ATLAS sourcesExperimenting with different algorithmsExpect to classify in z bins: (e.g.) 0-0.5, 0.5-1, 1-2, 2-4, 4-8
56 Solution: “statistical redshifts” Photometric redshifts are poor-mans spectroscopic redshiftsStatistical 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 1.1select polarised sources=> median z = 1.9select 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, http://arxiv. org/abs/1106