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Full-Text Articles in Physical Sciences and Mathematics
A Comparison Of X-Ray And Optical Emission In Cassiopeia A, Daniel J. Patnaude, Robert A. Fesen
A Comparison Of X-Ray And Optical Emission In Cassiopeia A, Daniel J. Patnaude, Robert A. Fesen
Dartmouth Scholarship
Broadband optical and narrowband Si XIII X-ray images of the young Galactic supernova remnant Cassiopeia A (Cas A) obtained over several decades are used to investigate spatial and temporal emission correlations on both large and small angular scales. The data examined consist of optical and near infrared ground-based and Hubble Space Telescope images taken between 1951 and 2011, and X-ray images from Einstein, ROSAT, and Chandra taken between 1979 and 2013. We find weak spatial correlations between the remnant’s X-ray and optical emission features on large scales, but several cases of good optical/X-ray correlations on small scales for features which …
Faint X‐Ray Structure In The Crab Pulsar Wind Nebula, F. D. Seward, W. H. Tucker, R. A. Fesen
Faint X‐Ray Structure In The Crab Pulsar Wind Nebula, F. D. Seward, W. H. Tucker, R. A. Fesen
Dartmouth Scholarship
We report on a Chandra observation of the Crab Nebula that gives the first clear view of the faint boundary of the Crab's X-ray-emitting pulsar wind nebula. There is structure in all directions. Fingers, loops, bays, and the south pulsar jet all indicate that either filamentary material or the magnetic field is controlling the relativistic electrons. In general, spectra soften as distance from the pulsar increases but do not change rapidly along linear features. This is particularly true for the pulsar jet. The termination of the jet is abrupt; the east side is close to an [O III] optical filament, …
Chandra Observations Of The Luminous, Oxygen‐Rich Supernova Remnants In The Irregular Galaxy Ngc 4449, Daniel J. Patnaude, Robert A. Fesen
Chandra Observations Of The Luminous, Oxygen‐Rich Supernova Remnants In The Irregular Galaxy Ngc 4449, Daniel J. Patnaude, Robert A. Fesen
Dartmouth Scholarship
An analysis of a 29 ks Chandra ACIS-S observation of the young, Cassiopeia A–like supernova remnant in the irregular galaxy NGC 4449 is presented. The observed 0.5–2.1 keV spectrum reveals the likely presence of several emission lines. A nonequilibrium ionization fit to the spectrum suggests an overabundance of oxygen around 20 times solar, consistent with the remnant’s UV and optical emission-line properties. We discuss the remnant’s approximate X-ray–derived elemental abundances and compare its X-ray spectrum and luminosity with other oxygen-rich remnants
An Isolated, Recently Shocked Ism Cloud In The Cygnus Loop Supernova Remnant, D. J. Patnaude, R. A. Fesen, J. C. Raymond, N. A. Levenson
An Isolated, Recently Shocked Ism Cloud In The Cygnus Loop Supernova Remnant, D. J. Patnaude, R. A. Fesen, J. C. Raymond, N. A. Levenson
Dartmouth Scholarship
Spatially resolved ROSAT X-ray and ground-based optical data for the southwestern region of the Cygnus Loop supernova remnant (SNR) reveal in unprecedented detail the very early stages of a blast-wave interaction with an isolated interstellar cloud. Numerous internal cloud shock fronts near the upstream flow and along the cloud edges are visible optically as sharp filaments of enhanced H emission. Faint X-ray emission is seen along a line of Balmer-dominated shock filaments north and south of the cloud with an estimated X-ray gas temperature of 1.2 106 K (0.11 keV), corresponding to a shock velocity of 290 km s1 . …