erschel ATLAS Steve Eales and the H-ATLAS and HerMES teams

Transcription

1 The erschel ATLAS Steve Eales and the H-ATLAS and HerMES teams

2 The Herschel ATLAS The widest area survey with Herschel (~ 550 sq deg) Consortium of 150+ astronomers worldwide led by Cardiff and Nottingham (Eales, Dunne) Covering 5 bands with PACs and SPIRE ( microns) in fast parallel mode 5 sigma sensitivities of 132, 126, 33, 36 and 45 mjy / beam from m Detect ~10 5 sources to z~3 Astrophysical Terahertz Large Area Survey Primary Aim: to provide the kind of leap 2Df/SDSS made in the optical for the FIR/sub-mm

3 NGP and Equatorial SGP SDP field Fields chosen to allow maximum overlap with existing and planned surveys GALEX, 2dF, SDSS, GAMA, UKIDSS, KIDS, VIKING, PanSTARRS, DES, SPT, SASSy and to be accessible to new facilities which will be valuable for follow-up ALMA, SKA and prototypes, SCUBA2, LOFAR, e-merlin

4 Key Science Themes in ATLAS 1. Local Universe Survey 2. Synergies with Planck 3. The Herschel Lens Survey 4. AGN and rare objects 5. Large scale structure and High-z galaxies 6. Galactic star and planet formation

5 Herschel ATLAS Science Demonstration Field Observations carried out in November 2009; public data release in November 2010 (hatlas.org) 4 x 4 degrees 3% of final area 6600 sources detected at >5σ The Blob Surface brightness sensitivity for extended sources is very similar to Planck at 350 and 500 microns

6 What Planck Should Have Seen at 500 microns

7 The Blob Intriguing Galactic Object Either very low mass prestellar core/protostar (0.01 solar masses).. Or normal mass but very far out of the plane Being followed up by SMA to see whether this is a prestellar core or a protostar.

8 H-ATLAS: Local Universe Census of dust and obscured SF in ~70,000 galaxies at z<0.3 UNBIASED luminosity and dust mass functions by Hubble type, environment and redshift Unbiased probe of dust in ellipticals & dwarfs. Overlap with UV / optical / NIR surveys allows energy balance modelling and assessment of impact of dust on optical surveys Survey contains 60 Abell clusters including Coma evolution of ISM and SFR in a range of environments and potential to study intra-cluster dust We are collaborating with the GAMA consortium who are carrying out a redshift survey in the equatorial fields

9 Local SD science 5 sigma 250 m catalogue of 6600 sources XID to optical (r<22.4) using SDSS DR7 and a likelihood ratio method (Smith et al. astroph ) 2240 reliable counterparts (>80% reliability) N(z) of identified sources

10 Evolution of the 250 m Luminosity Function Dye et al, A&A special issue LIRGS

11 What is causing the evolution? Galaxies a few billion years ago contained more gas Dunne et al. MN, submitted

12 Cosmic Accountancy The Far-IR/submm background contains 50% of all the energy ever emitted by galaxies The deepest Herschel surveys at 250μm (HERMES) resolve about 15-20% of the background. H-ATLAS resolves much less than this.

13 The HerMES Results LIRG ULIRG Luminosity function shows strong evolution out to z=1, but there is no evidence for strong evolution at z > 1 More metals and star are formed at 0.5<z<1.5 than at 1.5<z<2.5 Eales et al. 2010, A&A special issue 12 out of 26 galaxies at 0.8<z<1.2 show clear spiral morphology A lot of the star formation in the Universe has occurred in spirals

14 CIB fluctuations with Herschel-SPIRE SPIRE 250, 350 and 500 micron three color image of the Lockman-Hole, 16 deg 2. 1-halo 2-halo Unresolved CIB fluctuations capture the spatial clustering of all submm galaxies Minimum halo mass is about 3x10 11 solar masses Star formation rate constant at z>1 Amblard, A., Cooray, A., Serra, P. et al. Submillimetre Galaxies reside in Dark Matter Halos with mass greater than 3x10 11 Msun, Nature in press (2011). Fluctuations require significant star formation be high beyond z ~3 See the poster (Cooray et al)

15 The H-ATLAS lensing survey Models predict that the brighest 500-micron sources should be a mixture of nearby galaxies, blazars and lensed galaxies (Negrello et al. 2007) In principle, it should be easy to filter out the blazars and nearby galaxies

16 Brightest galaxies in SDP field z spec = ID1 ID5 z spec = sources with S 500μm > 100 mjy in SDP field the blob, one blazar and four nearby galaxies z spec = ID 6 ID7 z spec =

17 The other sources Gravitational Lenses z spec = ID81 ID9 : S 500μm = 175 ± 28 mjy ID11 : S 500μm = 238 ± 37 mjy ID17 : S 500μm = 220 ± 34 mjy ID81 : S 500μm = 166 ± 27 mjy ID130 : S 500μm = 108 ± 18 mjy z spec = ID11 ID130 z phot = 0.68±0.06 ID9 z spec = z phot = 0.77±0.13 ID17... what about the sub-mm SED?

18 GRAVITATIONAL LENS CANDIDATES ID81 - ID130: UV/optical/near-IR SED inconsistent with sub-mm SED! best lens candidates for DDT follow-ups z > 2.5

19 GRAVITATIONAL LENS CANDIDATES ID81 CSO/Z-spec blind redshift determination for ID81 (March ) from observations of the CO ladder ID81 Credit: The Zspec team

20 Gravitational Lens candidates ID81 Redshift confirmed by follow-ups with PdB Interferometer (March ) and GBT/Zpectrometer (March ) ID81 Credit: R. Neri, P. Cox, A. Beelen, H. Dannerbauer, F. Bertoldi

21 The First Five Candidates Source Optical redshift CO redshift (photo-z) % success rate for finding lenses! Negrello et al. 2010, Science, 330, 800

22 How many Herschel sources are lensed? A calculation based on an evolving population of darkmatter halos implies that the probability of a source at z=3 being magnified by a factor of >2 is (Pearson et al. in prep). The steep Herschel source counts imply the fraction of sources in any sample that are lensed is 5% 1.2x10 4 lensed sources in survey Clements et al. 2010

23 What use is lensing? Study star-forming galaxies at z>3 with better resolution and sensitivity Investigate the structures of the lenses (both in baryons and dark matter) Test the paradigm of structure evolution from N(M,z) for the lenses is the evolution of dark halos really like the theorists say? Measure cosmological parameters from N(M,z) for the lenses Use JWST to find additional sources for each lens, giving another route to finding cosmological parameters Simulation of reconstruction of unlensed structure from an SMA map (Simon Dye)

24 Possible Herschel-Planck Projects High-resolution observations of Planck point sources, including testing completeness and accuracy of recovered parameters for Planck point-source catalogue Investigations of Galactic dust on all scales (talk by Lagache) Removing the effects of dusty high-z galaxies (lensed and unlensed) for Planck SZ sample Integrated Sachs-Wolfe effect, using Herschel to trace the distribution of matter at 1<z<3 Investigation of CMB lensing, using the Herschel sources to trace the distribution of matter at 3>z>1

25 The Herschel-SPIRE Legacy Survey Map 4000 sq. degrees on the sky with SPIRE instrument in fast scan mode. 780 hours to complete, single scans in SPIRE fast-mode (60 /sec) (a) find 2.5 to 3 million dusty galaxies, with 1.5 million at z~2, 10,000 a ~1000 at z >5. Follow-up targets for ALMA, SPICA etc. (b) 2000 strongly lensed bright sources: a goldmine for cosmology! (c) 400 proto-clusters regions at z~2 to 5, trace structure formation (d) ISW at z=2 with SMGs: A strong probe of modified gravity theories acceleration (e) large-scale clustering constrain primordial non-gaussianity with a h probe than Euclid/LSST sky HSLS Planck see the HSLS White Paper on the arxiv

26 Next Steps for Herschel ATLAS 150 square degrees of GAMA fields observed and all the SPIRE data reduced Virtually all of the Northen Galactic Pole (150 square degrees) observed over Christmas South Galactic Pole (250 square degrees) scheduled for observations in Summer 2011

27 GAMA 9-hours 25,000 sources

28 Summary The Herschel ATLAS is a key legacy survey of 550 sq degrees. Strengths are unbiased selection, wide areal coverage and huge statistical power 300 square degrees now completed 22 papers published, in press or submitted First set of data (SDP field) was released to the community at the beginning of November (h-atlas.org) Lots of possible Herschel-Planck projects Anyone interested in the Herschel-SPIRE Legacy Survey should contact Asantha Cooray (acoorary@uci.edu) or Steve Eales (stephen.eales@astro.cf.ac.uk)