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Full-Text Articles in Physics
Precision Measurement Of The Most Distant Spectroscopically Confirmed Supernova Ia With The Hubble Space Telescope, D Rubin, R A. Knop, E Rykoff, G Aldering, R Amanullah, K Barbary, M S. Burns, A Conley, N Connolly, S Deustua, V Fadeyev, H K. Fakhouri, A S. Fruchter, R A. Gibbons, G Goldhaber, A Goobar, E Y. Hsiao, Xiaosheng Huang, M Kowalski, C Lidman, J Meyers, J Nordin, S Perlmutter, C Saunders, A Spadafora, V Stanishev, N Suzuki, L Wang, Supernova Cosmology Project
Precision Measurement Of The Most Distant Spectroscopically Confirmed Supernova Ia With The Hubble Space Telescope, D Rubin, R A. Knop, E Rykoff, G Aldering, R Amanullah, K Barbary, M S. Burns, A Conley, N Connolly, S Deustua, V Fadeyev, H K. Fakhouri, A S. Fruchter, R A. Gibbons, G Goldhaber, A Goobar, E Y. Hsiao, Xiaosheng Huang, M Kowalski, C Lidman, J Meyers, J Nordin, S Perlmutter, C Saunders, A Spadafora, V Stanishev, N Suzuki, L Wang, Supernova Cosmology Project
Physics and Astronomy
We report the discovery of a redshift 1.71 supernova in the GOODS North field. The Hubble Space Telescope (HST) ACS spectrum has almost negligible contamination from the host or neighboring galaxies. Although the rest frame sampled range is too blue to include any Si ii line, a principal component analysis allows us to confirm it as a Type Ia supernova with 92% confidence. A recent serendipitous archival HST WFC3 grism spectrum contributed a key element of the confirmation by giving a host-galaxy redshift of 1.713 +/- 0.007. In addition to being the most distant SN Ia with spectroscopic confirmation, this …
The Escape Fraction Of Ionizing Radiation From Galaxies, A Benson, Aparna Venkatesan, J Shull
The Escape Fraction Of Ionizing Radiation From Galaxies, A Benson, Aparna Venkatesan, J Shull
Physics and Astronomy
The escape of ionizing radiation from galaxies plays a critical role in the evolution of gas in galaxies, and the heating and ionization history of the intergalactic medium. We present semi-analytic calculations of the escape fraction of ionizing radiation for both hydrogen and helium from galaxies ranging from primordial systems to disk-type galaxies that are not heavily dust-obscured. We consider variations in the galaxy density profile, source type, location, and spectrum, and gas overdensity/distribution factors. For sufficiently hard first-light sources, the helium ionization fronts closely track or advance beyond that of hydrogen. Key new results in this work include calculations …