Related papers: Gravitational Lensing and the Hubble Deep Field
Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structure, formation, and evolution). Using the gravitational lensing theory and cluster mass distribution model, we try to…
We present constraints on the cosmological constant lambda_0 and the density parameter Omega_0 from joint constraints from the analyses of gravitational lensing statistics of the Jodrell Bank-VLA Astrometric Survey (JVAS), optical…
Damped Lyman-alpha absorbers are believed to be associated with galactic disks. We show that gravitational lensing can therefore affect the statistics of these systems. First, the magnification bias due to lensing raises faint QSOs above a…
The 0th, 1st and 2nd derivatives of a ``Fermat potential'' give the three D's of gravitational lensing: delay, deflection and distortion. Observations of these delays, deflections and distortions for doubly and quadruply imaged quasars give…
The ages of two old galaxies (53W091, 53W069) at high redshifts are used to constrain the value of the cosmological constant in a flat universe ($\Lambda$CDM) and the density parameter $\Omega_M$ in Friedmann-Robertson-Walker (FRW) models…
(Abridged) We present a detailed analysis of the number count and photometric redshift distribution of faint galaxies in the Hubble Deep Field (HDF), paying a special attention to the selection effects including the cosmological dimming of…
Measured time delays between the images of a gravitationally lensed source can lead to a determination of the Hubble constant ($H_o$), but only if the lensing mass distribution is well understood. The inability to sufficiently constrain…
The quadruple system PG 1115+080 is the second gravitational lens with a reported measurement of the Hubble constant. In addition to the primary lens, three nearby galaxies are believed to contribute significantly to the lensing potential.…
We measure the size-luminosity relation of photometrically-selected galaxies within the redshift range $z\sim6-9$, using galaxies lensed by six foreground Hubble Frontier Fields (HFF) clusters. The power afforded by strong gravitational…
With the increase in the number of observed gravitational wave (GW) signals, detecting strongly lensed GWs by galaxies has become a real possibility. Lens galaxies also contain microlenses (e.g., stars and black holes), introducing further…
Gravitational lensing causes the distribution of observed brightnesses of standard candles at a given redshift to be highly non-gaussian. The distribution is strongly, and asymmetrically, peaked at a value less than the expected value in a…
We investigate the effects of gravitational lensing due to intervening galaxies on the recently discovered Type Ia supernova at z=1.7, SN1997ff, in the Hubble Deep Field North. We find that it is possible to obtain a wide range of…
We measure the z=0 B-band optical luminosity function (LF) for galaxies selected in a blind HI survey. The total LF of the HI selected sample is flat, with Schechter parameters M*=-19.38_{-0.62}^{+1.02} + 5 log h mag and…
We have developed a technique to systematically discover and study high-redshift supernovae that can be used to measure the cosmological parameters. We report here results based on the initial seven of >28 supernovae discovered to date in…
In a flat, k=0 cosmology with galaxies that approximate singular isothermal spheres, gravitational lens image separations should be uncorrelated with source redshift. But in an open k=-1 cosmology such gravitational lens image separations…
Standard $\Omega_0=1$ cold dark matter (CDM) needs $0.27 < \sigma_8 < 0.63$ ($2\sigma$) to fit the observed number of large separation lenses, and the constraint is nearly independent of $H_0=100h^{-1}\kms$ Mpc$^{-1}$. This range is…
By using the comoving distance, we derive an analytic expression for the optical depth of gravitational lensing, which depends on the redshift to the source and the cosmological model characterized by the cosmic mass density parameter…
We re-investigated the use of the Hubble diagram to measure the cosmological constant ($\Lambda$) and the mass density of the Universe ($\Omega_M$). We find an important focusing effect in $\Lambda$ for redshifts about 3. This effect…
Extending over three Hubble Space Telescope (HST) cycles, the Hubble Frontier Fields (HFF) initiative constitutes the largest commitment ever of HST time to the exploration of the distant Universe via gravitational lensing by massive galaxy…
The case for a flat Cold Dark Matter model with a positive cosmological constant $\Lambda$ has been recently strongly advocated by some theoreticians. In this paper we give the observers point of view to the light of the most recent…