Bahram Mobasher

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  • Bahram Mobasher, Shardha Jogee, Tomas Dahlen, Duilia De Mello, Ray A Lucas, Christopher J Conselice +2 others
  • 2008
A comparative study of the rest-frame morphology and structural properties of optically selected starburst galaxies at redshift z 1 is carried out using multi-waveband (BV iz) high resolution images taken by the Advanced Camera for Surveys (ACS) as part of the Great Observatories Origins Deep Survey (GOODS). We classify galaxies into starburst, early and(More)
We have discovered 16 Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to provide the first conclusive evidence for cosmic deceleration that preceded the current epoch of cosmic acceleration. These objects, discovered during the course of the GOODS ACS Treasury program, include 6 of the 7 highest-redshift SNe Ia known,(More)
Ordinary baryonic particles (such as protons and neutrons) account for only one-sixth of the total matter in the Universe. The remainder is a mysterious 'dark matter' component, which does not interact via electromagnetism and thus neither emits nor reflects light. As dark matter cannot be seen directly using traditional observations, very little is(More)
We present a three-dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey, the largest ever optical imaging program performed in space. We have measured the shapes of galaxies for the telltale distortions caused by weak gravitational lensing and traced the growth of that signal as a function of redshift. Using both 2D and 3D analyses,(More)
We have discovered 21 new Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to trace the history of cosmic expansion over the last 10 billion years. These objects, which include 13 spectroscopically confirmed SNe Ia at z ≥ 1, were discovered during 14 epochs of reimaging of the GOODS fields North and South over two years(More)
  • Shardha Jogee, Fabio D Barazza, Hans-Walter Rix, James Davies, Inge Heyer, Steven V W Beckwith +14 others
  • 2004
One-third of present-day spirals host optically visible strong bars that drive their dynamical evolution. However, the fundamental question of how bars evolve over cosmological times has yet to be resolved, and even the frequency of bars at intermediate redshifts remains controversial. We investigate the frequency of bars out to z ∼ 1 drawing on a sample of(More)
We describe the angular power spectrum of resolved sources at 3.6 µm (L-band) in Spitzer imaging data of the GOODS HDF-N, the GOODS CDF-S, and the NDWFS Boötes field in several source magnitude bins. We also measure angular power spectra of resolved sources in the Boötes field at K S and J-bands using ground-based IR imaging data. In the three bands, J, K S(More)
The redshift distribution of near-IR selected galaxies is often used to attempt to discriminate between the classical view of galaxy formation, in which present-day luminous galaxies were assembled at early times and evolve due to the passive aging of their stellar populations, and that of hierarchical structure formation, in which galaxies were assembled(More)
We present a three dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey ⋆ , the largest ever optical imaging program performed in space. We have measured the shapes of galaxies for the telltale distortions caused by weak gravitational lensing, and traced the growth of that signal as a function of redshift. Using both 2D and 3D(More)
  • Leonidas A Moustakas, Stefano Casertano, Chris Conselice, Mark E Dickinson, Peter Eisenhardt, Henry C Ferguson +9 others
  • 2003
Using U ′-through K s-band imaging data in the GOODS-South field, we construct a large, complete sample of 275 " extremely red objects " (EROs; K s < 22.0, R−K s > 3.35; AB), all with deep HST /ACS imaging in B 435 , V 606 , i 775 , and z 850 , and well-calibrated photometric redshifts. Quantitative concentration and asymmetry measurements fail to separate(More)