Understanding the Dark Universe with 3D Weak Gravitational Lensing
Lead Research Organisation:
University of Edinburgh
Department Name: Inst for Astronomy
Abstract
Although we can see a great amount of stars, galaxies and dust in the Universe, many independent observations now agree that the combined mass in these baryonic systems is insufficient to account for more than a few percent of the entire budget. The missing mass is usually explained via an additional but mysterious 'dark matter' component, which interacts with baryons only through gravity. In particular, since dark matter does not emit or even reflect light, it can not be seen by ordinary means. A second, even more mysterious component known as 'dark energy' has recently become apparent. This acts as a repulsive force on very large scales, and is currently accelerating the expansion of the universe away from the trajectory started by the Big Bang. Their existence challenges the standard model of particle physics, and can test General Relativity. As evidenced by the support from governmental agencies and the popular press in the 'Scientific Justification' submitted with this proposal, unravelling these twin puzzles is widely viewed as the outstanding problem in physics. This is also the focus of my proposal. DARK MATTER: Since we can not see dark matter directly, we must measure its indirect effect on the observable universe. Light is deflected or 'gravitationally lensed' by gravitational potentials. This distorts the apparent shapes of distant galaxies as their light passes near mass along our line of sight. Near dense mass concentrations, such as clusters of galaxies, strong lensing distorts individual background galaxies into prominent arcs and Einstein rings. Along most lines of sight, the much weaker distortion cannot be detected from one galaxy image, because the original shape of that galaxy is unknown. However, galaxy morphologies are uncorrelated and, in the absence of lensing, should have no preferred orientation. Using this fact, we can recover the weak lensing signal by averaging the shapes of adjacent galaxies that have been lensed by the same intervening mass. From the degree of correlation between their shapes, it is thus possible to infer the total mass distribution, iincluding dark matter. DARK ENERGY: A gravitational lens system operates like an optical lens in many ways. For example, the lens (mass) is most effective when placed half-way between the source and the observer. The efficiency of a lens at a fixed location depends upon the distance to the source. By observing the distortion in (and redshift of) many galaxies behind one cluster, we can trace the redshift-distance relation. This describes the overall expansion of the universe, for which each candidate for dark energy predicts a different characteristic signal. This simultaneous, dual test of both the growth of structure and of large-scale geometry is unique to gravitational lensing. Unfortunately, the galaxy shape distortions induced by gravitational lensing are typically an order of magnitude smaller than spurious distortions added by imperfections in telescope optics and during transit through the Earth's atmosphere. To increase the precision of weak lensing measurements, these potential biases must be more finely controlled. The onus now placed upon weak gravitational lensing from the wider community is to verify such control, and to reliably ascertain the absolute calibration of the measured signal. The latter is particularly crucial because it can not be internally constrained from observations using current techniques. I have carried out major lensing surveys from the William Herschel, Keck, Subaru and Hubble Space telescopes, attempting to understand their varying instrumental systematics. I have also used this experience to develop advanced techniques for image analysis and for signal interpretation. My goal is to fully exploit the rich potential of large, dedicated weak lensing surveys that have been approved and will be available within five years. However, this will require further, intense development of techniques in advance.
People |
ORCID iD |
| Richard Massey (Principal Investigator / Fellow) |
Publications
Amara A
(2012)
The COSMOS density field: a reconstruction using both weak lensing and galaxy distributions The COSMOS density field
in Monthly Notices of the Royal Astronomical Society
Bergé J
(2008)
Combined analysis of weak lensing and X-ray blind surveys
in Monthly Notices of the Royal Astronomical Society
Bogdanovic T
(2011)
USING FARADAY ROTATION TO PROBE MAGNETOHYDRODYNAMIC INSTABILITIES IN INTRACLUSTER MEDIA
in The Astrophysical Journal
Bradac M
(2008)
Revealing the Properties of Dark Matter in the Merging Cluster MACS J0025.4-1222
in The Astrophysical Journal
Bridle S
(2010)
Results of the GREAT08 Challenge?: an image analysis competition for cosmological lensing Results of the GREAT08 Challenge
in Monthly Notices of the Royal Astronomical Society
Bridle S
(2009)
Handbook for the GREAT08 Challenge: An image analysis competition for cosmological lensing
in The Annals of Applied Statistics
Cameron E
(2010)
Bars in early- and late-type discs in COSMOS Bars in early- and late-type discs in COSMOS
in Monthly Notices of the Royal Astronomical Society
Dobke B
(2010)
Astronomical Image Simulation for Telescope and Survey Development
in Publications of the Astronomical Society of the Pacific
Dobke Benjamin M.
(2010)
Astronomical Image Simulation for Telescope and Survey Development
in PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
Ellis R
(2009)
90 years on - the 1919 eclipse expedition at Príncipe
in Astronomy & Geophysics
Faure C
(2009)
ON THE CONTRIBUTION OF LARGE-SCALE STRUCTURE TO STRONG GRAVITATIONAL LENSING
in The Astrophysical Journal
Faure C
(2008)
First Catalog of Strong Lens Candidates in the COSMOS Field
in The Astrophysical Journal Supplement Series
Faure C
(2008)
Erratum: "First Catalog of Strong Lens Candidates in the COSMOS Field" (ApJS, 176, 19 [2008])
in The Astrophysical Journal Supplement Series
Ferry M
(2008)
Color, 3D simulated images with shapelets
in Astroparticle Physics
Gabor J
(2009)
ACTIVE GALACTIC NUCLEUS HOST GALAXY MORPHOLOGIES IN COSMOS
in The Astrophysical Journal
Giodini S
(2010)
RADIO GALAXY FEEDBACK IN X-RAY-SELECTED GROUPS FROM COSMOS: THE EFFECT ON THE INTRACLUSTER MEDIUM
in The Astrophysical Journal
Giodini S
(2009)
STELLAR AND TOTAL BARYON MASS FRACTIONS IN GROUPS AND CLUSTERS SINCE REDSHIFT 1*
in The Astrophysical Journal
Hamana T
(2009)
Subaru Weak-Lensing Survey II: Multi-Object Spectroscopy and Cluster Masses
in Publications of the Astronomical Society of Japan
Jullo E
(2012)
COSMOS: STOCHASTIC BIAS FROM MEASUREMENTS OF WEAK LENSING AND GALAXY CLUSTERING
in The Astrophysical Journal
Kasliwal M
(2008)
A Comparison of Weak-Lensing Measurements from Ground- and Space-Based Facilities
in The Astrophysical Journal
Kitching T
(2012)
Image analysis for cosmology: results from the GREAT10 Galaxy Challenge GREAT10 Galaxy Challenge
in Monthly Notices of the Royal Astronomical Society
Kitching T
(2015)
Image analysis for cosmology: Shape measurement challenge review & results from the Mapping Dark Matter challenge
in Astronomy and Computing
Kitching T
(2011)
Gravitational Lensing Accuracy Testing 2010 (GREAT10) Challenge Handbook
in The Annals of Applied Statistics
Leauthaud A
(2010)
A WEAK LENSING STUDY OF X-RAY GROUPS IN THE COSMOS SURVEY: FORM AND EVOLUTION OF THE MASS-LUMINOSITY RELATION
in The Astrophysical Journal
Leauthaud A
(2012)
NEW CONSTRAINTS ON THE EVOLUTION OF THE STELLAR-TO-DARK MATTER CONNECTION: A COMBINED ANALYSIS OF GALAXY-GALAXY LENSING, CLUSTERING, AND STELLAR MASS FUNCTIONS FROM z = 0.2 to z = 1
in The Astrophysical Journal
Mandelbaum R
(2012)
Precision simulation of ground-based lensing data using observations from space Ground-based image simulation
in Monthly Notices of the Royal Astronomical Society
Massey R
(2009)
Cosmology: Dark is the new black.
in Nature
Massey R
(2010)
The dark matter of gravitational lensing
in Reports on Progress in Physics
Massey R
(2010)
Charge transfer inefficiency in the Hubble Space Telescope since Servicing Mission 4 Charge transfer inefficiency in HST since SM4
in Monthly Notices of the Royal Astronomical Society: Letters
Massey R
(2011)
Cluster bulleticity Cluster bulleticity
in Monthly Notices of the Royal Astronomical Society
Massey R
(2010)
Pixel-based correction for Charge Transfer Inefficiency in the Hubble Space Telescope Advanced Camera for Surveys
in Monthly Notices of the Royal Astronomical Society
Massey R
(2010)
The dark matter of gravitational lensing
Massey Richard
(2010)
Digging into dark matter with weak gravitational lensing
in ASP Conf.Ser.
McInnes R
(2009)
First lensing measurements of SZ-detected clusters
in Monthly Notices of the Royal Astronomical Society: Letters
Merten J
(2011)
Creation of cosmic structure in the complex galaxy cluster merger Abell 2744 The galaxy cluster merger Abell 2744
in Monthly Notices of the Royal Astronomical Society
Oesch P
(2010)
THE BUILDUP OF THE HUBBLE SEQUENCE IN THE COSMOS FIELD
in The Astrophysical Journal
Rhodes J
(2012)
Space-quality data from balloon-borne telescopes: The High Altitude Lensing Observatory (HALO)
in Astroparticle Physics
Rhodes J
(2010)
The Effects of Charge Transfer Inefficiency (CTI) on Galaxy Shape Measurements
in Publications of the Astronomical Society of the Pacific
Sargent M
(2010)
THE OPACITY OF GALACTIC DISKS AT z ~ 0.7
in The Astrophysical Journal
Schmidt F
(2012)
A DETECTION OF WEAK-LENSING MAGNIFICATION USING GALAXY SIZES AND MAGNITUDES
in The Astrophysical Journal
Shan H
(2012)
WEAK LENSING MEASUREMENT OF GALAXY CLUSTERS IN THE CFHTLS-WIDE SURVEY
in The Astrophysical Journal
Shioya Y
(2008)
The Ha Luminosity Function and Star Formation Rate at z ˜ 0.24 in the COSMOS 2 Square Degree Field
in The Astrophysical Journal Supplement Series
Taylor J
(2012)
MEASURING THE GEOMETRY OF THE UNIVERSE FROM WEAK GRAVITATIONAL LENSING BEHIND GALAXY GROUPS IN THE HST COSMOS SURVEY
in The Astrophysical Journal
Vanderveld R
(2011)
Lossy Compression of Weak-Lensing Data
in Publications of the Astronomical Society of the Pacific
Voigt L
(2012)
The impact of galaxy colour gradients on cosmic shear measurement Galaxy colour gradients and shear measurement
in Monthly Notices of the Royal Astronomical Society
{Capak}, P. And {Aussel}, H. And {Ajiki}, M. And {McCracken}, H.~J. And {Mobasher}, B. And {Scoville}, N. And {Shopbell}, P. And {Taniguchi}, Y. And {Thompson}, D. And {Tribiano}, S. And {Sasaki}, S. And {Blain}, A.~W. And {Brusa}, M. And {Carilli}, C. And {Comastri}, A. And {Carollo}, C.~M. And {Cassata}, P. And {Colbert}, J. And {Ellis}, R.~S. And {Elvis}, M. And {Giavalisco}, M. And {Green}, W. And {Guzzo}, L. And {Hasinger}, G. And {Ilbert}, O. And {Impey}, C. And {Jahnke}, K. And {Kartalte
(2008)
COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
in VizieR Online Data Catalog
{Coe}, D.~A. And {Dupke}, R. And {Benitez}, N. And {Broadhurst}, T. And {Massey}, R. And {Zitrin}, A. And {Merten}, J. And {Cypriano}, E. And {Braglia}, F. And {Frye}, B. And {Meneghetti}, M. And {Moustakas}, L. And {Rhodes}, J. And {Krick}, J. And {Sodre}, L. And {Bregman}, J. And {Jimenez-Teja}, Y. And {Bernstein}, R.
(2011)
More Powerful than a Speeding ''Bullet''? New HST Images and Analysis of the Galaxy Cluster Merger Abell 2744
{Dupke}, R.~A. And {Merten}, J. And {Coe}, D. And {Massey}, R. And {Zitrin}, A. And {Benitez}, N. And {Owers}, M. And {Frye}, B. And {Bregman}, J. And {Cypriano}, E. And {Sodre}, Jr., L. And {Rhodes}, J. And {Moustakas}, L. And {Meneghetti}, M. And {Krick}, J. And {Carrasco}, R. And {Braglia}, F. And {Okabe}, N. And {Broadhurst}, T.
(2011)
Untangling the Evils Unleashed by Pandora's Cluster, Abell 2744