UCL Astrophysics

~100 people (20 academic staff)

• Research Areas: Stellar astrophysics, Star formation, Astro-chemistry,Cosmology, Atmospheric Physics, exo-planets, Optics, Mill Hill Observatory

UCL Astrophysics Group Cosmologists

Ofer Lahav

Tomek Kacprzak

Barney Rowe

Michael Hirsch

Sarah Bridle

Sree Balan

Fotini Economou

Alex Merson

Emily Hall

Lisa Voigt

Joe Zuntz

Jason McEwen

Filipe Abdalla

Emma Chapman

Maayane Sougmanac

Laura Wolz

Boris Leistedt

Stephen Feeney

Hiranya Peiris

Manda Banerji

Donnacha Kirk Lucy Clerkin

Niall MacCrann

Aurelien Benoit-LevyWalter Santos

A brief history of UCL P&A Cosmology

• Start of group: 2004 Ofer Lahav

• 1st generation (2004): – Sarah Bridle -> Professor, Manchester– Jochen Weller -> Professor, Munich

• 2nd generation (2008):– Hiranya Peiris– Filipe Abdalla

• 3rd generation (2012):– Two appointments

Filipe AbdallaRadio/OpticalCosmology

EoR Weak lensing

Euclid DES SKA

Sarah BridleCosmic Shear

Galaxy shapes DES

Dark energy

Ofer LahavGalaxy surveys

MegaZ-LRG 2MRS Photo-z

HST-MCT DES Euclid

Hiranya PeirisEarly Universe

Planck Inflation

Isotropy Non-Gaussianity

Statistical Cosmology from Surveys

GR tests

Future prospectsThe Dark Energy Survey

• Einstein’s cosmological constant• A new fluid called Dark Energy• General Relativity is wrong

Why is the Universe

Accelerating?

5 DES lenses – assembly at UCL

Polishing & coating coordinated by UCL (with £1.76M STFC funding, PI: Lahav)

C3

DES First Light12 Sep 2012

NGC1365

Photometric Redshifts

Collister & Lahav 2004http://www.star.ucl.ac.uk/~lahav/annz.html

Neutrino Mass

Thomas, Abdalla & Lahav, PRL (2010) Lahav, Kiakotou, Abdalla & Blake, MNRAS (2010)Swanson, Percival & Lahav, MNRAS (2010)Kiakotou, Elgaroy & Lahav, PRD (2008)

• Constraints from MegaZ-LRG 700,000 galaxies• 0.05 eV < Total neutrino mass < 0.28 eV (95% CL)

• Forecast constraints from DES

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Advanced ERCTESTDE team

DESpec: Spectroscopic

follow up of DES

• 4000–fibre $40M (?) instrument• 7 million galaxy spectra, target list from DES, • DETF Stage IV experiment• DES+DESpec can distinguish DE from ModGrav

Kirk, Lahav, Bridle, Abdalla, Jouvel et al. (in preparation)Jouvel, Abdalla, Blahav, Bridle et al.(in preparation)DESpec white paper Abdalla et al. astro-ph:1209.2451

ESA Euclid

• During the design phase: – Photo-z needs (Abdalla et al. 08)– Coulour dependence of the psf

(Cypriano et al. 10 Voigt et al. 11)

• During the implementation phase– Science working groups.– Science ready data (OU-LE3)– Photo-z (OU-PHZ)– Shear measurement (OU-SHE)

PI: Postman; UCL coI: Lahav + Host & Jouvel

25 clustersTesting conflict with LCDMDiscovering z=10 galaxy candidates

Weak Gravitational Lensing & Intrinsic alignments

Image analysis of galaxy shapes

Figure from the GREAT08 Handbook. Bridle et al 2009

Barney Rowe now co-leading next GREAT-like challenge

Add foregrounds 100-1000 times largerCosmic signal

LOFAR - EoR

• EoR Data being taken now!

• Working on Foreground removal

Recovered signal (Chapman et al. 12a,b)

Yatawata et al. 12

Square Kilometre Array: SKA

• Forecasts, simulations• New imaging techniques

Status of Surveys we are involved in

•HST-CLASH: Observations started in Nov 2010

•Planck: See Hiranya’s talk...

•LOFAR: Telescope is ready, KSP taking data now.

•DES: First light Sep. Survey starts Dec.

•Euclid: Selected by ESA in Oct 2011. Launch 2019

•DESpec, BigBOSS: Study funding from STFC

•SKA: Site selection done. Studies for implementation phase.

Synergies between P&A and other London institutes

• Imperial -> Euclid, Planck, Astro-statistics, Theory, EoR/SKA

• Kings -> Early universe, HEP

• QM-> Early Universe, VISTA

• MSSL (UCL) -> Euclid, Weak lensing, LOFAR