Asymmetric surface brightness structure of caustic crossing arc in SDSS J1226+2152: a case for dark matter substructure

  title={Asymmetric surface brightness structure of caustic crossing arc in SDSS J1226+2152: a case for dark matter substructure},
  author={Liang Dai and Alexander A. Kaurov and Keren Sharon and Michael K. Florian and Jordi Miralda-Escud'e and Tejaswi Venumadhav and Brenda Frye and Jane R. Rigby and Matthew B. Bayliss},
We study the highly magnified arc SGAS J122651.3+215220 caused by a star-forming galaxy at $z_s=2.93$ crossing the lensing caustic cast by the galaxy cluster SDSS J1226+2152 ($z_l=0.43$), using Hubble Space Telescope observations. We report in the arc several asymmetric surface brightness features whose angular separations are a fraction of an arcsecond from the lensing critical curve and appear to be highly but unequally magnified image pairs of underlying compact sources, with one brightest… Expand
Gravitational Lensing Formalism in a Curved Arc Basis: A Continuous Description of Observables and Degeneracies from the Weak to the Strong Lensing Regime
  • S. Birrer
  • Physics
  • The Astrophysical Journal
  • 2021
Gravitationally lensed curved arcs provide a wealth of information about the underlying lensing distortions. Extracting precise lensing information from extended sources is a key component in manyExpand
Hamilton’s Object – a clumpy galaxy straddling the gravitational caustic of a galaxy cluster: constraints on dark matter clumping
We report the discovery of a ‘folded’ gravitationally lensed image, ’Hamilton’s Object’, found in a HST image of the field near the AGN SDSS J223010.47-081017.8 (which has redshift 0.62). The lensedExpand
Kinematics of the Circumgalactic Medium of a z = 0.77 Galaxy from Mg ii Tomography
Galaxy evolution is thought to be driven in large part by the flow of gas between galaxies and the circumgalactic medium (CGM), a halo of metal-enriched gas extending out to ≳100 kpc from eachExpand
Search for Lensed Gravitational Waves Including Morse Phase Information: An Intriguing Candidate in O2
We search for strongly lensed and multiply imaged gravitational wave signals in the second observing run of Advanced LIGO and Advanced Virgo (O2). We exploit a new source of information, theExpand
Statistical microlensing towards magnified high-redshift star clusters
We study light variability of gravitationally magnified high-redshift star clusters induced by a foreground population of microlenses. This arises as the incoherent superposition of light variationsExpand
Vortices and waves in light dark matter
In a galactic halo like the Milky Way, bosonic dark matter particles lighter than about 100 eV have a de Broglie wavelength larger than the average inter-particle separation and are therefore wellExpand


Highly Magnified Stars in Lensing Clusters: New Evidence in a Galaxy Lensed by MACS J0416.1-2403
We examine a caustic-straddling arc at $z=0.9397$ in the field of the galaxy cluster MACS J0416.1-2403 ($z=0.397$) using archival multiband HST images and show that its surface brightness exhibitsExpand
Probing dark matter substructure in the gravitational lens HE 0435-1223 with the WFC3 grism
Strong gravitational lensing provides a powerful test of Cold Dark Matter (CDM) as it enables the detection and mass measurement of low mass haloes even if they do not contain baryons. Compact lensedExpand
Probing Dark Matter Subhalos in Galaxy Clusters Using Highly Magnified Stars
Luminous stars in background galaxies straddling the lensing caustic of a foreground galaxy cluster can be individually detected due to extreme magnification factors of $\sim 10^2$--$10^3$, asExpand
Gravitational Lensing Signatures of Axion Dark Matter Minihalos in Highly Magnified Stars
Axions are a viable candidate for Cold Dark Matter (CDM) which should generically form minihalos of sub-planetary masses from white-noise isocurvature density fluctuations if the Peccei-Quinn phaseExpand
Extreme magnification of an individual star at redshift 1.5 by a galaxy-cluster lens
Galaxy-cluster gravitational lenses can magnify background galaxies by a total factor of up to ~50. Here we report an image of an individual star at redshift z = 1.49 (dubbed MACS J1149 Lensed StarExpand
Dark Matter under the Microscope: Constraining Compact Dark Matter with Caustic Crossing Events
A galaxy cluster acts as a cosmic telescope over background galaxies but also as a cosmic microscope magnifying the imperfections of the lens. The diverging magnification of lensing caustics enhancesExpand
Compound Gravitational Lensing as a Probe of Dark Matter Substructure within Galaxy Halos
We show how observations of multiply imaged quasars at high redshift can be used as a probe of dark matter clumps (subhalos with masses 109 M☉) within the virialized extent of more massive lensingExpand
We report the discovery of two strongly lensed z ~ 3 Lyman break galaxies (LBGs) discovered as u-band dropouts as part of the SDSS Giant Arcs Survey (SGAS). The first, SGAS J122651.3+215220 at z =Expand
Searching for Highly Magnified Stars at Cosmological Distances: Discovery of a Redshift 0.94 Blue Supergiant in Archival Images of the Galaxy Cluster MACS J0416.1-2403
Individual highly magnified stars have been recently discovered at lookback times of more than half the age of the Universe, in lensed galaxies that straddle the critical curves of massive galaxyExpand
A new survey for giant arcs
We report on the first results of an imaging survey to detect strong gravitational lensing targeting the richest clusters selected from the photometric data of the Sloan Digital Sky Survey (SDSS)Expand