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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
The Discovery Of A Gravitationally Lensed Supernova Ia At Redshift 2.22, David Rubin, Brian Hayden, Xiaosheng Huang, Greg Aldering, R Amanullah, K Barbary, K Boone, M Brodwin, S E. Deustua, S Dixon, P Eisenhardt, A S. Fruchter, A H. Gonzalez, A Goobar, R R. Gupta, I Hook, M. James Jee, A G. Kim, M Kowalski, C Lidman, E V. Linder, K Luther, J Nordin, R Pain, Saul Perlmutter, Z Raha, M Rigault, P Ruiz-Lapuente, C Saunders, C Sofiatti, A L. Spadafora, S A. Stanford, D Stern, N Suzuki, S C. Williams
The Discovery Of A Gravitationally Lensed Supernova Ia At Redshift 2.22, David Rubin, Brian Hayden, Xiaosheng Huang, Greg Aldering, R Amanullah, K Barbary, K Boone, M Brodwin, S E. Deustua, S Dixon, P Eisenhardt, A S. Fruchter, A H. Gonzalez, A Goobar, R R. Gupta, I Hook, M. James Jee, A G. Kim, M Kowalski, C Lidman, E V. Linder, K Luther, J Nordin, R Pain, Saul Perlmutter, Z Raha, M Rigault, P Ruiz-Lapuente, C Saunders, C Sofiatti, A L. Spadafora, S A. Stanford, D Stern, N Suzuki, S C. Williams
Physics and Astronomy
We present the discovery and measurements of a gravitationally lensed supernova (SN) behind the galaxy cluster MOO J1014+0038. Based on multi-band Hubble Space Telescope and Very Large Telescope (VLT) photometry of the supernova, and VLT spectroscopy of the host galaxy, we find a 97.5% probability that this SN is a SN Ia, and a 2.5% chance of a CC SN. Our typing algorithm combines the shape and color of the light curve with the expected rates of each SN type in the host galaxy. With a redshift of 2.2216, this is the highest redshift SN Ia discovered with a spectroscopic …
Direct Collapse To Supermassive Black Hole Seeds With Radiation Transfer: Cosmological Haloes, Kazem Ardaneh, Yang Luo, Isaac Shlosman, Kentaro Nagamine, John H. Wise, Michael C. Begelman
Direct Collapse To Supermassive Black Hole Seeds With Radiation Transfer: Cosmological Haloes, Kazem Ardaneh, Yang Luo, Isaac Shlosman, Kentaro Nagamine, John H. Wise, Michael C. Begelman
Physics and Astronomy Faculty Publications
We have modelled direct collapse of a primordial gas within dark matter haloes in the presence of radiative transfer, in high-resolution zoom-in simulations in a cosmological framework, down to the formation of the photosphere and the central object. Radiative transfer has been implemented in the flux-limited diffusion (FLD) approximation. Adiabatic models were run for comparison. We find that (a) the FLD flow forms an irregular central structure and does not exhibit fragmentation, contrary to adiabatic flow which forms a thick disc, driving a pair of spiral shocks, subject to Kelvin–Helmholtz shear instability forming fragments; (b) the …
Cosmological Consequences Of Classical Flavor-Space Locked Gauge Field Radiation, Jannis Bielefeld, Robert R. Caldwell
Cosmological Consequences Of Classical Flavor-Space Locked Gauge Field Radiation, Jannis Bielefeld, Robert R. Caldwell
Dartmouth Scholarship
We propose a classical SU(2) gauge field in a flavor-space locked configuration as a species of radiation in the early Universe, and show that it would have a significant imprint on a primordial stochastic gravitational wave spectrum. In the flavor-space locked configuration, the electric and magnetic fields of each flavor are parallel and mutually orthogonal to other flavors, with isotropic and homogeneous stress energy. Due to the non-Abelian coupling, the gauge field breaks the symmetry between left- and right-circularly polarized gravitational waves. This broken chiral symmetry results in a unique signal: nonzero cross-correlation of the cosmic microwave background temperature and …
Direct Collapse To Supermassive Black Hole Seeds With Radiative Transfer: Isolated Halos, Yang Luo, Kazem Ardaneh, Isaac Shlosman, Kentaro Nagamine, John H. Wise, Mitchell C. Begelman
Direct Collapse To Supermassive Black Hole Seeds With Radiative Transfer: Isolated Halos, Yang Luo, Kazem Ardaneh, Isaac Shlosman, Kentaro Nagamine, John H. Wise, Mitchell C. Begelman
Physics and Astronomy Faculty Publications
Direct collapse within dark matter haloes is a promising path to form supermassive black hole seeds at high redshifts. The outer part of this collapse remains optically thin. However, the innermost region of the collapse is expected to become optically thick and requires to follow the radiation field in order to understand its evolution. So far, the adiabatic approximation has been used exclusively for this purpose. We apply radiative transfer in the flux-limited diffusion (FLD) approximation to solve the evolution of coupled gas and radiation for isolated haloes. We find that (1) the photosphere forms at 10−6 pc and …
Grb 130427a Afterglow: A Test For Grb Models, Massimiliano De Pasquale, M. J. Page, D. A. Kann, S. R. Oates, S. Schulze, Bing Zhang, Z. Cano, B. Gendre, D. Malesani, A. Rossi, N. Gehrels, E. Troja, L. Piro, M. Boër, G. Stratta
Grb 130427a Afterglow: A Test For Grb Models, Massimiliano De Pasquale, M. J. Page, D. A. Kann, S. R. Oates, S. Schulze, Bing Zhang, Z. Cano, B. Gendre, D. Malesani, A. Rossi, N. Gehrels, E. Troja, L. Piro, M. Boër, G. Stratta
Physics & Astronomy Faculty Research
Gamma-ray Burst 130427A had the largest fluence for almost 30 years. With an isotropic energy output of 8.5×1053 erg and redshift of 0.34, it combined a very high energy release with a relative proximity to Earth in an unprecedented fashion. Sensitive X-ray facilities such as {\it XMM-Newton} and {\it Chandra} detected the afterglow of this event for a record-breaking baseline of 90 Ms. We show the X-ray light curve of GRB 130427A of this event over such an interval. The light curve shows an unbroken power law decay with a slope of α=1.31 over more than three decades in time. …