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Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Studying The Small Scale Ism Structure With Supernovae, F. Patat, N. L. J. Cox, J. Parrent, D. Branch
Studying The Small Scale Ism Structure With Supernovae, F. Patat, N. L. J. Cox, J. Parrent, D. Branch
Dartmouth Scholarship
In this work we explore the possibility of using the fast expansion of a Type Ia supernova photosphere to detect extra-galactic ISM column density variations on spatial scales of ∼100 AU on time scales of a few months. We constructed a simple model which describes the expansion of the photodisk and the effects of a patchy interstellar cloud on the observed equivalent width of Nai D lines. Using this model we derived the behavior of the equivalent width as a function of time, spatial scale and amplitude of the column density fluctuation
Comparing Various Multi-Component Global Heliosphere Models, H.-R. Müller, V. Florinski, J. Heerikhuisen, V. V. Izmodenov
Comparing Various Multi-Component Global Heliosphere Models, H.-R. Müller, V. Florinski, J. Heerikhuisen, V. V. Izmodenov
Dartmouth Scholarship
Modeling of the global heliosphere seeks to investigate the interaction of the solar wind with the partially ionized local interstellar medium. Models that treat neutr al hydrogen self-consistently and in great detail, together with the plasma, but that neglect magnetic fields, constitute a sub-category within global heliospheric models. There are several different modeling strategies used for this sub-category in the literature. Differences and commonalities in the modeling results from different strategies are pointed out.
Grb 021004: A Possible Shell Nebula Around A Wolf‐Rayet Star Gamma‐Ray Burst Progenitor, N. Mirabal, J. P. Halpern, Ryan Chornock, Alexei V. Filippenko, D. M. Terndrup, E. Armstrong, J. Kemp, J. R. Thorstensen, M. Tavarez, C. Espaillat
Grb 021004: A Possible Shell Nebula Around A Wolf‐Rayet Star Gamma‐Ray Burst Progenitor, N. Mirabal, J. P. Halpern, Ryan Chornock, Alexei V. Filippenko, D. M. Terndrup, E. Armstrong, J. Kemp, J. R. Thorstensen, M. Tavarez, C. Espaillat
Dartmouth Scholarship
The rapid localization of GRB 021004 by the HETE-2 satellite allowed nearly continuous monitoring of its early optical afterglow decay, as well as high-quality optical spectra that determined a redshift of z3 = 2.328 for its host galaxy, an active starburst galaxy with strong Ly emission and several absorption lines. Spectral observations show multiple absorbers at z3A = 2.323, z3B= 2.317, and z3C = 2.293 blueshifted by ~450, ~990, and ~3155 km s-1, respectively, relative to the host galaxy Lyα emission. We argue that these correspond to a fragmented shell nebula that has …
An Optical Survey Of Outlying Ejecta In Cassiopeia A: Evidence For A Turbulent, Asymmetric Explosion, Robert A. Fesen
An Optical Survey Of Outlying Ejecta In Cassiopeia A: Evidence For A Turbulent, Asymmetric Explosion, Robert A. Fesen
Dartmouth Scholarship
A deep optical survey of the Cassiopeia A supernova remnant has revealed dozens of new emissionline ejecta knots out beyond the remnantÏs bright nebular shell. Most of the newly detected knots exhibit a 4500È 7500 A. spectrum dominated by [N II ] jj 6548,6583 line emissions. After accounting for possible decelerations, the estimated space velocities for about four dozen of these [N II ] knots suggest a nearly isotropic ^ 10,000 km s~1 ejection velocity. However, a small group along the southwestern limb show signi‹cantly higher velocities of up to 12,000 km s~1 . Over 20 outlying O] S emission …