Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
Articles 1 - 3 of 3
Full-Text Articles in Physical Sciences and Mathematics
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 …
Characterization Of The Supersonic Flowing Microwave Discharge Using Two Dimensional Plasma Tomography, Milka Nikolic, A. Samolov, F. Čučkov, S. Popović, L. Vušković, A. Godunov
Characterization Of The Supersonic Flowing Microwave Discharge Using Two Dimensional Plasma Tomography, Milka Nikolic, A. Samolov, F. Čučkov, S. Popović, L. Vušković, A. Godunov
Physics and Astronomy
A tomographic numerical method based on the two-dimensional Radon formula for a cylindrical cavity has been employed for obtaining spatial distributions of the argon excited levels. The spectroscopy measurements were taken at different positions and directions to observe populations of excited species in the plasmoid region and the corresponding excitation temperatures. Excited argon states are concentrated near the tube walls, thus, confirming the assumption that the post discharge plasma is dominantly sustained by travelling surface wave. An automated optical measurement system has been developed for reconstruction of local plasma parameters of the plasmoid structure formed in an argon supersonic flowing …