Medezinski, Elinor, Broadhurst, Tom, Umetsu, Keiichi, Oguri, Masamune, Rephaeli, Yoel, Benítez, Narciso
We carefully examine the luminous content of three high mass clusters, A1703 (z=0.258), A370 (z=0.375) and RXJ1347-11 (z=0.45), with deep Subaru imaging. Accurate three-colour data allows us to...
A new gravitational lens from the MUSCLES survey: ULAS J082016.1+081216 (2009)
Jackson, Neal, Ofek, Eran O., Oguri, Masamune
We present observations of a new double-image gravitational lens system, ULAS J082016.1+081216, of image separation 2.3" and high (~6) flux ratio. The system is selected from the Sloan Digital Sky...
Self-Calibrated Cluster Counts as a Probe of Primordial Non-Gaussianity (2009)
We show that the ability to probe primordial non-Gaussianity with cluster counts is drastically improved by adding the excess variance of counts which contains information on the clustering. The...
A new gravitational lens from the MUSCLES survey: ULAS J082016.1+081216 (2009)
Jackson, Neal, Ofek, Eran O., Oguri, Masamune
We present observations of a new double-image gravitational lens system, ULAS J082016.1+081216, of image separation 2.3 arcsec and high (∼6) flux ratio. The system is selected from the Sloan...
Oguri, Masamune, Hennawi, Joseph F., Gladders, Michael D., Dahle, Haakon, Natarajan, Priyamvada, Dalal, Neal, ...
We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed...
Discovery of A Very Bright, Strongly-Lensed z=2 Galaxy in the SDSS DR5 (2008)
Lin, Huan, Buckley-Geer, Elizabeth, Allam, Sahar S., Tucker, Douglas L., Diehl, H. Thomas, Kubik, Donna, ...
We report on the discovery of a very bright z = 2.00 star-forming galaxy that is strongly lensed by a foreground z=0.422 luminous red galaxy (LRG). This system was found in a systematic search for...
Five New High-Redshift Quasar Lenses from the Sloan Digital Sky Survey (2008)
Inada, Naohisa, Oguri, Masamune, Shin, Min-Su, Kayo, Issha, Strauss, Michael A., Morokuma, Tomoki, ...
We report the discovery of five gravitationally lensed quasars from the Sloan Digital Sky Survey (SDSS). All five systems are selected as two-image lensed quasar candidates from a sample of...
Mass models and environment of the new quadruply lensed quasar SDSS J1330+1810 (2008)
Oguri, Masamune, Inada, Naohisa, Blackburne, Jeffrey A., Shin, Min-Su, Kayo, Issha, Strauss, Michael A., ...
We present the discovery of a new quadruply lensed quasar. The lens system, SDSS J1330+1810 at z_s=1.393, was identified as a lens candidate from the spectroscopic sample of the Sloan Digital Sky...
Inada, Naohisa, Oguri, Masamune, Falco, Emilio E., Broadhurst, Tom J., Ofek, Eran O., Kochanek, Christopher S., ...
We present the results of deep spectroscopy for the central region of the cluster lens SDSS J1004+4112 with the Subaru telescope. A secure detection of an emission line of the faint blue stellar...
What is the largest Einstein radius in the universe? (2008)
Oguri, Masamune, Blandford, Roger D.
The Einstein radius plays a central role in lens studies as it characterises the strength of gravitational lensing. The distribution of Einstein radii near the upper cutoff should probe the largest...
Discovery of a Giant Lya Emitter Near the Reionization Epoch (2008)
Ouchi, Masami, Ono, Yoshiaki, Egami, Eiichi, Saito, Tomoki, Oguri, Masamune, McCarthy, Patrick J., ...
We report the discovery of a giant Lya emitter (LAE) with a Spitzer/IRAC counterpart near the reionization epoch at z=6.595. The giant LAE is found from the extensive 1 deg^2 Subaru narrow-band...
Comparison of Cluster Lensing Profiles with Lambda CDM Predictions (2008)
Broadhurst, Tom, Umetsu, Keiichi, Medezinski, Elinor, Oguri, Masamune, Rephaeli, Yoel
We derive lens distortion and magnification profiles of four well known clusters observed with Subaru. Each cluster is very well fitted by the general form predicted for Cold Dark Matter (CDM)...
The SDSS Discovery of a Strongly Lensed Post-Starburst Galaxy at z=0.766 (2008)
Shin, Min-Su, Strauss, Michael A., Oguri, Masamune, Inada, Naohisa, Falco, Emilio E., Broadhurst, Tom, ...
We present the first result of a survey for strong galaxy-galaxy lenses in Sloan Digital Sky Survey (SDSS) images. SDSS J082728.70+223256.4 was selected as a lensing candidate using selection...
ULAS J234311.93-005034.0: A gravitational lens system selected from UKIDSS and SDSS (2008)
Jackson, Neal, Ofek, Eran O., Oguri, Masamune
We report the discovery of a new gravitational lens system. This object, ULAS J234311.93-005034.0, is the first to be selected by using the new UKIRT Infrared Deep Sky Survey (UKIDSS), together with...
The third image of the large-separation lensed quasar SDSS J1029+26231 (2008)
Oguri, Masamune, Ofek, Eran O., Inada, Naohisa, Morokuma, Tomoki, Falco, Emilio E., Kochanek, Christopher S., ...
We identify a third image in the unique quasar lens SDSS J1029+2623, the second known quasar lens produced by a massive cluster of galaxies. The spectrum of the third image shows similar emission and...
A new survey for giant arcs (2008)
Hennawi, Joseph F., Gladders, Michael D., Oguri, Masamune, Dalal, Neal, Koester, Benjamin, Natarajan, Priyamvada, ...
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)...
Oguri, Masamune, Inada, Naohisa, Strauss, Michael A., Kochanek, Christopher S., Richards, Gordon T., Schneider, Donald P., ...
We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., Shin, Min-Su, Richards, Gordon T., Hennawi, Joseph F., ...
We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the...
The Third Image of the Large-Separation Lensed Quasar SDSS J1029+2623 (2008)
Oguri, Masamune, Ofek, Eran O., Inada, Naohisa, Morokuma, Tomoki, Falco, Emilio E., Kochanek, Christopher S., ...
We identify a third image in the unique quasar lens SDSS J1029+2623, the second known quasar lens produced by a massive cluster of galaxies. The spectrum of the third image shows similar emission and...
Difference Imaging of Lensed Quasar Candidates in the SDSS Supernova Survey Region (2008)
Lacki, Brian C., Kochanek, Christopher S., Stanek, Krzysztof Z., Inada, Naohisa, Oguri, Masamune
Difference imaging provides a new way to discover gravitationally lensed quasars because few non-lensed sources will show spatially extended, time variable flux. We test the method on lens candidates...
Oguri, Masamune, Inada, Naohisa, Strauss, Michael A., Kochanek, Christopher S., Richards, Gordon T., Schneider, Donald P., ...
We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., Shin, Min-Su, Richards, Gordon T., Hennawi, Joseph F., ...
We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the...
Ofekofe, Eran O., Oguri, Masamune, Jackson, Neal, Inada, Naohisa, Kayo, Issha
We report the discovery of a new gravitationally lensed quasar, SDSS J131339.98+515128.3, at a redshift of 1.875 with an image separation of 1.24 arcsec. The lensing galaxy is clearly detected in...
A new quadruply lensed quasar: SDSS J125107.57+293540.5 (2007)
Kayo, Issha, Inada, Naohisa, Oguri, Masamune, Hall, Patrick B., Kochanek, Christopher S., Richards, Gordon T., ...
We report the discovery of a quadruply imaged quasar, SDSS J125107.57+293540.5, selected from the Sloan Digital Sky Survey. Follow-up imaging reveals that the system consists of four blue pointlike...
Oguri, Masamune, Inada, Naohisa, Strauss, Michael A., Kochanek, Christopher S., Richards, Gordon T., Schneider, Donald P., ...
We present cosmological results from the statistics of lensed quasars in the Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of the selection function, we compute the...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., Shin, Min-Su, Richards, Gordon T., Hennawi, Joseph F., ...
We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the...
Discovery of Four Gravitationally Lensed Quasars from the Sloan Digital Sky Survey (2007)
Oguri, Masamune, Inada, Naohisa, Clocchiatti, Alejandro, Kayo, Issha, Shin, Min-Su, Hennawi, Joseph F., ...
We present the discovery of four gravitationally lensed quasars selected from the spectroscopic quasar catalog of the Sloan Digital Sky Survey. We describe imaging and spectroscopic follow-up...
A New Quadruply Lensed Quasar: SDSSJ125107.57+293540.5 (2007)
Kayo, Issha, Inada, Naohisa, Oguri, Masamune, Hall, Patrick B., Kochanek, Christopher S., Richards, Gordon T., ...
We report the discovery of a quadruply imaged quasar, SDSSJ125107.57+293540.5, selected from the Sloan Digital Sky Survey. Follow-up imaging reveals that the system consists of four blue point-like...
Is There a Quad Problem among Optical Gravitational Lenses? (2007)
Most of optical gravitational lenses recently discovered in the Sloan Digital Sky Survey Quasar Lens Search (SQLS) have two-images rather than four-images, in marked contrast to radio lenses for...
Analytic models of plausible gravitational lens potentials (2007)
Baltz, Edward A., Marshall, Phil, Oguri, Masamune
Gravitational lenses on galaxy scales are plausibly modelled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sersic profile to describe the distribution of baryonic...
Clustering of high-redshift (z >= 2.9) quasars from the sloan digital sky survey (2007)
Shen, Yue, Strauss, Michael A., Oguri, Masamune, Hennawi, Joseph F., Fan, Xiaohui, Richards, Gordon T., ...
We study the two-point correlation function of a uniformly selected sample of 4426 luminous optical quasars with redshift 2:9 z 5:4 selected over 4041 deg2 from the Fifth Data Release of the Sloan...
Clustering of High Redshift ($z\ge 2.9$) Quasars from the Sloan Digital Sky Survey (2007)
Shen, Yue, Strauss, Michael A., Oguri, Masamune, Hennawi, Joseph F., Fan, Xiaohui, Richards, Gordon T., ...
(Abridged) We study the two-point correlation function of a uniformly selected sample of 4,426 luminous optical quasars with redshift $2.9 \le z\le 5.4$ selected over 4041 deg$^2$ from the Fifth Data...
Morokuma, Tomoki, Inada, Naohisa, Oguri, Masamune, Ichikawa, Shin-Ichi, Kawano, Yozo, Tokita, Kouichi, ...
We report the discovery of the two-image gravitationally lensed quasar SDSS J133222.62+034739.9 (SDSS J1332+ 0347) with an image separation of ¼1:1400. This system consists of a source quasar at zs...
Two new gravitationally lensed double quasars from the Sloan Digital Sky Survey (2007)
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., White, Richard L., Kayo, Issha, Kochanek, Christopher S., ...
We report the discoveries of the two-image gravitationally lensed quasars SDSS J074653.03+440351.3 and SDSS J140624.82+612640.9, selected from the Sloan Digital Sky Survey (SDSS). SDSS J0746+4403,...
SDSS J1029_2623: a gravitationally lensed quasar with an image separation of 22.5 inches (2006)
Inada, Naohisa, Oguri, Masamune, Morokuma, Tomoki, Doi, Mamoru, Yasuda, Naoki, Becker, Robert H., ...
We report the discovery of a cluster-scale lensed quasar, SDSS J1029+2623, selected from the Sloan Digital Sky Survey. The lens system exhibits two lensed images of a quasar at z p 2.197. The image...
SDSS J1029+2623: A Gravitationally Lensed Quasar with an Image Separation of 22.5 Arcseconds (2006)
Inada, Naohisa, Oguri, Masamune, Morokuma, Tomoki, Doi, Mamoru, Yasuda, Naoki, Becker, Robert H., ...
We report the discovery of a cluster-scale lensed quasar, SDSS J1029+2623, selected from the Sloan Digital Sky Survey. The lens system exhibits two lensed images of a quasar at z_s=2.197. The image...
A New Survey for Giant Arcs (2006)
Hennawi, Joseph F., Gladders, Michael D., Oguri, Masamune, Dalal, Neal, Koester, Benjamin, Natarajan, Priyamvada, ...
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)...
Morokuma, Tomoki, Inada, Naohisa, Oguri, Masamune, Ichikawa, Shin-Ichi, Kawano, Yozo, Tokita, Kouichi, ...
We report the discovery of the two-image gravitationally lensed quasar SDSS J133222.62+034739.9 (SDSS J1332+0347) with an image separation of Delta_theta=1.14". This system consists of a source...
Two New Gravitationally Lensed Double Quasars from the Sloan Digital Sky Survey (2006)
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., White, Richard L., Kayo, Issha, Kochanek, Christopher S., ...
We report the discoveries of the two-image gravitationally lensed quasars, SDSS J0746+4403 and SDSS J1406+6126, selected from the Sloan Digital Sky Survey (SDSS). SDSS J0746+4403, which will be...
Time delays between lensed multiple images have been known to provide an interesting probe of the Hubble constant, but such application is often limited by degeneracies with the shape of lens...
Arc sensitivity to cluster ellipticity, asymmetries and substructures (2006)
Meneghetti, Massimo, Argazzi, Rodolfo, Pace, Francesco, Moscardini, Lauro, Dolag, Klaus, Bartelmann, Matthias, ...
We investigate how ellipticity, asymmetries and substructures separately affect the ability of galaxy clusters to produce strong lensing events, i.e. gravitational arcs, and how they influence the...
QSO Absorption Lines from QSOs (2006)
Bowen, David V., Hennawi, Joseph F., Menard, Brice, Chelouche, Doron, Inada, Naohisa, Oguri, Masamune, ...
We present the results of a search for metal absorption lines in the spectra of background QSOs whose sightlines pass close to foreground QSOs. We detect MgII(2796,2803) absorption in Sloan Digital...
The Sloan Digital Sky Survey Quasar Lens Search. I. Candidate Selection Algorithm (2006)
Oguri, Masamune, Inada, Naohisa, Pindor, Bartosz, Strauss, Michael A., Richards, Gordon T., Hennawi, Joseph F., ...
We present an algorithm for selecting an uniform sample of gravitationally lensed quasar candidates from low-redshift (0.6
Gravitational lensing effects on the gamma-ray burst Hubble diagram (2006)
Oguri, Masamune, Takahashi, Keitaro
Gamma-Ray Bursts (GRBs) offer a potential way to extend the Hubble diagram to very high redshifts and to constrain the nature of dark energy in a way complementary to distant type Ia supernovae....
Quasars Probing Quasars I: Optically Thick Absorbers Near Luminous Quasars (2006)
Hennawi, Joseph F., Prochaska, Jason X., Burles, Scott, Strauss, Michael A., Richards, Gordon T., Schlegel, David J., ...
With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We search 149 moderate resolution background...
We investigate the dependence of the time delays for the large-separation gravitationally lensed quasar SDSS J1004+4112 on the inner mass profile of the lensing cluster. Adopting the mass model whose...
Inada, Naohisa, Oguri, Masamune, Becker, Robert H., White, Richard L., Gregg, Michael D., Schechter, Paul L., ...
We report the discoveries of two, two-image gravitationally lensed quasars selected from the Sloan Digital Sky Survey: SDSS J0806+2006 at z_s=1.540 and SDSS J1353+1138 at z_s=1.629 with image...
Biermann Mechanism in Primordial Supernova Remnant and Seed Fields (2005)
Hanayama, Hidekazu, Takahashi, Keitaro, Kotake, Kei, Oguri, Masamune, Ichiki, Kiyotomo, Ohno, Hiroshi
We have studied the generation of magnetic fields by the Biermann mechanism in the pair-instability supernovae explosions of the first stars. The Biermann mechanism produces magnetic fields in the...
SDSSJ102111.02+491330.4: A Newly Discovered Gravitationally Lensed Quasar (2005)
Pindor, Bart, Eisenstein, Daniel J., Gregg, Michael D., Becker, Robert H., Inada, Naohisa, Oguri, Masamune, ...
We report follow-up observations of two gravitational lens candidates identified in the Sloan Digital Sky Survey (SDSS) dataset. We have confirmed that SDSS J102111.02+491330.4 is a previously...
Characterizing a cosmic string with the statistics of string lensing (2005)
Oguri, Masamune, Takahashi, Keitaro
The deep imaging of the field of an observed lensing event by a cosmic string reveals many additional lensing events. We study the statistics of such string lensing. We derive explicit expressions...
The image separation distribution of strong lenses: Halo versus subhalo populations (2005)
We present a halo model prediction of the image separation distribution of strong lenses. Our model takes account of the subhalo population, which has been ignored in previous studies, as well as the...
Discovery of Multiply Imaged Galaxies behind the Cluster and Lensed Quasar SDSS J1004+4112 (2005)
Sharon, Keren, Ofek, Eran O., Smith, Graham P., Broadhurst, Tom J., Maoz, Dan, Kochanek, Christopher S., ...
We have identified three multiply imaged galaxies in Hubble Space Telescope images of the redshift z=0.68 cluster responsible for the large-separation quadruply lensed quasar, SDSS J1004+4112....
SDSS J0246-0825: A New Gravitationally Lensed Quasar from the Sloan Digital Sky Survey (2005)
Inada, Naohisa, Burles, Scott, Gregg, Michael D., Becker, Robert H., Schechter, Paul L., Eisenstein, Daniel J., ...
We report the discovery of a new two-image gravitationally lensed quasar, SDSS J024634.11-082536.2 (SDSS J0246-0825). This object was selected as a lensed quasar candidate from the Sloan Digital Sky...
The impact of lens galaxy environments on the image separation distribution (2005)
Oguri, Masamune, Keeton, Charles R., Dalal, Neal
We study the impact of lens galaxy environments on the image separation distribution of lensed quasars. We account for both environmental convergence and shear, using a joint distribution derived...
Can the Steep Mass Profile of A1689 Be Explained by a Triaxial Dark Halo? (2005)
Oguri, Masamune, Takada, Masahiro, Umetsu, Keiichi, Broadhurst, Tom
The steep mass profile of A1689 derived from recent detailed lensing observations is not readily reconciled with the low concentration halos predicted by the standard CDM model. However, halo...
Hennawi, Joseph F., Strauss, Michael A., Oguri, Masamune, Inada, Naohisa, Richards, Gordon T., Pindor, Bartosz, ...
We present a sample of 218 new quasar pairs with proper transverse separations R_prop < 1 Mpc/h over the redshift range 0.5 < z < 3.0, discovered from an extensive follow up campaign to find...
Inada, Naohisa, Oguri, Masamune, Keeton, Charles R., Eisenstein, Daniel J., Castander, Francisco J., Chiu, Kuenley, ...
We report the discovery of a fifth image in the large separation lensed quasar system SDSS J1004+4112. A faint point source located 0.2'' from the center of the brightest galaxy in the lensing...
Biermann Mechanism in Primordial Supernova Remnant and Seed Magnetic Fields (2005)
Hanayama, Hidekazu, Takahashi, Keitaro, Kotake, Kei, Oguri, Masamune, Ichiki, Kiyotomo, Ohno, Hiroshi
We study generation of magnetic fields by the Biermann mechanism in the pair-instability supernovae explosions of first stars. The Biermann mechanism produces magnetic fields in the shocked region...
Oguri, Masamune, Inada, Naohisa, Hennawi, Joseph F., Richards, Gordon T., Johnston, David E., Frieman, Joshua A., ...
We report the discovery of two doubly imaged quasars, SDSS J100128.61+502756.9 and SDSS J120629.65+433217.6, at redshifts of 1.838 and 1.789, and with image separations of 2.86" and 2.90",...
Inada, Naohisa, Oguri, Masamune, Keeton, Charles R., Eisenstein, Daniel J., Castander, Francisco J., Chiu, Kuenley, ...
We report on the discovery of a fifth lensed image in the large separation lensed quasar system SDSS J1004 + 4112. A faint point source located 0.''2 from the center of the brightest galaxy in the...
Lens Galaxy Environments and Anomalous Flux Ratios in Gravitational Lenses (2004)
The fraction of substructures required to account for anomalous flux ratios in gravitational lens systems appears to be higher than that predicted in the standard cold dark matter cosmology. We...
Oguri, Masamune, Inada, Naohisa, Hennawi, Joseph F., Richards, Gordon T., Johnston, David E., Frieman, Joshua A., ...
We report the discovery of two doubly-imaged quasars, SDSS J100128.61+502756.9 and SDSS J120629.65+433217.6, at redshifts of 1.838 and 1.789 and with image separations of 2.86'' and 2.90'',...
An Analytic Model of Superclusters (2004)
Oguri, Masamune, Takahashi, Keitaro, Ichiki, Kiyotomo, Ohno, Hiroshi
We construct an analytic model for the mass distributions of superclusters and clusters in each supercluster. Our model is a modification of the Press-Schechter theory, and defines superclusters as...
Strong Gravitational Lenses in a Cold Dark Matter Universe (2004)
We present theoretical and observational studies of strong gravitational lenses produced by clusters of galaxies. Our purpose is to test the Cold Dark Matter (CDM) model at small and highly...
Galaxy Structures and External Perturbations in Gravitational Lenses (2004)
Kawano, Yozo, Oguri, Masamune, Matsubara, Takahiko, Ikeuchi, Satoru
In modeling strong gravitational lens systems, one often adopts simple models, such as singular isothermal elliptical density plus lowest-order external perturbation. However, such simple models may...
Effects of Triaxiality on the Statistics of Large-Separation Gravitational Lenses (2004)
Oguri, Masamune, Keeton, Charles R.
We study the statistics of large-separation gravitational lens systems produced by non-spherical halos in the Cold Dark Matter (CDM) model. Specifically, we examine how the triaxiality of CDM halos...
WMAP Constraints on Decaying Cold Dark Matter (2004)
Ichiki, Kiyotomo, Oguri, Masamune, Takahashi, Keitaro
We re-formulate cosmological perturbations in the decaying cold dark matter model, and calculate cosmological microwave background (CMB) anisotropies. By comparing our theoretical predictions with...
Microlensing of the Broad Emission Line Region in the Quadruple Lens SDSS J1004+4112 (2004)
Richards, Gordon T., Keeton, Charles R., Pindor, Bartosz, Hennawi, Joseph F., Hall, Patrick B., Turner, Edwin L., ...
We present seven epochs of spectroscopy on the quadruply imaged quasar SDSS J1004+4112, spanning observed-frame time delays from 1 to 322 days. The spectra reveal differences in the emission lines...
Oguri, Masamune, Lee, Jounghun
We construct a realistic model for the dark halo substructures, and derive analytically their spatial, mass, and velocity distributions. Basically, our model is a modification of the Press-Schechter...
Oguri, Masamune, Inada, Naohisa, Keeton, Charles R., Pindor, Bartosz, Hennawi, Joseph F., Gregg, Michael D., ...
We study the recently discovered gravitational lens SDSS J1004+4112, the first quasar lensed by a cluster of galaxies. It consists of four images with a maximum separation of 14.62". The system was...
Sunyaev-Zel'dovich power spectrum with decaying cold dark matter (2003)
Takahashi, Keitaro, Oguri, Masamune, Ichiki, Kiyotomo
Recent studies of structures of galaxies and clusters imply that dark matter might be unstable and decay with lifetime $\Gamma^{-1}$ about the age of universe. We study the effects of the decay of...
SDSS J1335+0118: A New Two-Image Gravitational Lens (2003)
Oguri, Masamune, Inada, Naohisa, Castander, Francisco J., Gregg, Michael D., Becker, Robert H., Ichikawa, Shin-Ichi, ...
We report the discovery of the two-image gravitationally lensed quasar SDSS J1335+0118. The object was selected as a lens candidate from the Sloan Digital Sky Survey. The imaging and spectroscopic...
Oguri, Masamune, Lee, Jounghun, Suto, Yasushi
Statistics of lensed arcs in clusters of galaxies serve as a powerful probe of both the non-sphericity and the inner slope of dark matter halos. We develop a semi-analytic method to compute the...
Decaying Cold Dark Matter and the Evolution of the Cluster Abundance (2003)
Oguri, Masamune, Takahashi, Keitaro, Ohno, Hiroshi, Kotake, Kei
The cluster abundance and its redshift evolution are known to be a powerful tool to constrain the amplitude of mass fluctuations \sigma_8 and the mass density parameter \Omega_m0. We study the impact...
A gravitationally lensed quasar with quadruple images separated by 14.62arcseconds (2003)
Inada, Naohisa, Oguri, Masamune, Pindor, Bartosz, Hennawi, Joseph F., Chiu, Kuenley, Zheng, Wei, ...
Gravitational lensing is a powerful tool for the study of the distribution of dark matter in the Universe. The cold-dark-matter model of the formation of large-scale structures (that is, clusters of...
An attempt to measure the Hubble constant with gravitational lens time delays is often limited by the strong degeneracy between radial mass profiles of lens galaxies and the Hubble constant. We show...
How many arcminute-separation lenses are expected in the 2dF QSO survey? (2002)
Wide separation lensing statistics offer information about the density profile and abundance of dark halos. Recently a possible discovery of six quasar pairs, which may be lensed multiple images, was...
Gravitational Lensing Magnification and Time Delay Statistics for Distant Supernovae (2002)
Oguri, Masamune, Suto, Yasushi, Turner, Edwin L.
Strong gravitational lensing of distant supernovae (SNe), particularly Type Ia's, has some exploitable properties not available when other sorts of cosmologically distant sources are lensed. One such...
Constraints on the Baryonic Compression and Implications for the Fraction of Dark Halo Lenses (2002)
We predict the fraction of dark halo lenses, that is, the fraction of lens systems produced by the gravitational potential of dark halos, on the basis of a simple parametric model of baryonic...
It has been recognized that the arc statistics of gravitational lensing is a useful probe of the density profile of clusters of galaxies. We examine several systematic effects which are important in...
Strong Gravitational Lensing Time Delay Statistics and the Density Profile of Dark Halos (2001)
Oguri, Masamune, Taruya, Atsushi, Suto, Yasushi, Turner, Edwin L.
The distribution of differential time delays \Delta t between images produced by strong gravitational lensing contains information on the mass distributions in the lensing objects as well as on...
Probing the Core Structure of Dark Halos with Tangential and Radial Arc Statistics (2001)
Oguri, Masamune, Taruya, Atsushi, Suto, Yasushi
We study the arc statistics of gravitational lensing generated by dark matter halos in order to probe their density profile. We characterize the halo profile by two parameters, the inner slope of the...