FUSE Observations of the Loop I∕Local Bubble Interaction Region

2009 ◽  
Author(s):  
S. M. Sallmen ◽  
E. J. Korpela ◽  
H. Yamashita ◽  
Randall K. Smith ◽  
Steven L. Snowden ◽  
...  
Keyword(s):  
Interaction Region ◽  
Local Bubble ◽  
Bubble Interaction

scholarly journals FUSEObservations of the Loop I/Local Bubble Interaction Region

2008 ◽  
Vol 681 (2) ◽  
pp. 1310-1317 ◽  
Author(s):  
Shauna M. Sallmen ◽  
Eric J. Korpela ◽  
Hiroki Yamashita
Keyword(s):  
Interaction Region ◽  
Local Bubble ◽  
Bubble Interaction

scholarly journals Can the Local Bubble explain the radio background?

2021 ◽  
Vol 502 (2) ◽  
pp. 2807-2814
Author(s):  
Martin G H Krause ◽  
Martin J Hardcastle
Keyword(s):  
Magnetic Field ◽  
Energy Density ◽  
Radio Emission ◽  
Magnetic Energy ◽  
Cosmic Ray ◽  
Observational Constraints ◽  
Local Bubble ◽  
Magnetic Energy Density ◽  
Magnetic Field Model ◽  
Radio Background

ABSTRACT The ARCADE 2 balloon bolometer along with a number of other instruments have detected what appears to be a radio synchrotron background at frequencies below about 3 GHz. Neither extragalactic radio sources nor diffuse Galactic emission can currently account for this finding. We use the locally measured cosmic ray electron population, demodulated for effects of the Solar wind, and other observational constraints combined with a turbulent magnetic field model to predict the radio synchrotron emission for the Local Bubble. We find that the spectral index of the modelled radio emission is roughly consistent with the radio background. Our model can approximately reproduce the observed antenna temperatures for a mean magnetic field strength B between 3 and 5 nT. We argue that this would not violate observational constraints from pulsar measurements. However, the curvature in the predicted spectrum would mean that other, so far unknown sources would have to contribute below 100 MHz. Also, the magnetic energy density would then dominate over thermal and cosmic ray electron energy density, likely causing an inverse magnetic cascade with large variations of the radio emission in different sky directions as well as high polarization. We argue that this disagrees with several observations and thus that the magnetic field is probably much lower, quite possibly limited by equipartition with the energy density in relativistic or thermal particles (B = 0.2−0.6 nT). In the latter case, we predict a contribution of the Local Bubble to the unexplained radio background at most at the per cent level.

scholarly journals β–radioactive cosmic rays in a diffusion model: Test for a local bubble?

2002 ◽  
Vol 381 (2) ◽  
pp. 539-559 ◽  
Author(s):  
F. Donato ◽  
D. Maurin ◽  
R. Taillet
Keyword(s):  
Cosmic Rays ◽  
Diffusion Model ◽  
Model Test ◽  
Local Bubble

scholarly journals Fingerprint of Galactic Loop I on polarized microwave foregrounds

2018 ◽  
Vol 617 ◽  
pp. A90 ◽  
Author(s):  
Hao Liu
Keyword(s):  
Supernova Explosion ◽  
Large Area ◽  
Microwave Background ◽  
Local Bubble ◽  
Galactic Emission ◽  
Primordial Gravitational Waves ◽  
Polarized Emission ◽  
Supernova Explosions ◽  
Foreground Analysis ◽  
The Magnetic Field

Context. Currently, detection of the primordial gravitational waves using the B-mode of cosmic microwave background (CMB) is primarily limited by our knowledge of the polarized microwave foreground emissions. Improvements of the foreground analysis are therefore necessary. As we revealed in an earlier paper, the E-mode and B-mode of the polarized foreground have noticeably different properties, both in morphology and frequency spectrum, suggesting that they arise from different physicalprocesses, and need to be studied separately. Aims. I study the polarized emission from Galactic loops, especially Loop I, and mainly focus on the following questions: Does the polarized loop emission contribute predominantly to the E-mode or B-mode? In which frequency bands and in which sky regions can the polarized loop emission be identified? Methods. Based on a well known result concerning the magnetic field alignment in supernova explosions, a theoretical expectation is established that the loop polarizations should be predominantly E-mode. In particular, the expected polarization angles of Loop I are compared with those from the real microwave band data of WMAP and Planck. Results and conclusions. The comparison between model and data shows remarkable consistency between the data and our expectations at all bands and for a large area of the sky. This result suggests that the polarized emission of Galactic Loop I is a major polarized component in all microwave bands from 23 to 353 GHz, and a considerable part of the polarized foreground likely originates from a local bubble associated with Loop I, instead of the far more distant Galactic emission. This result also provides a possible way to explain the E-to-B excess problem by contribution of the loops. Finally, this work may also provide the first geometrical evidence that the Earth was hit by a supernova explosion.

scholarly journals Plasma Lens Backgrounds at a Future Linear Collider

2003 ◽  
Vol 18 (16) ◽  
pp. 2857-2869
Author(s):  
Achim W. Weidemann ◽  
P. Chen ◽  
C.-K. Ng
Keyword(s):  
Linear Collider ◽  
Interaction Region ◽  
Interaction Processes ◽  
Linear Colliders ◽  
Beam Parameters ◽  
Event Rates ◽  
Different Sources ◽  
Detector Technology ◽  
Future Linear Collider

A 'plasma lens' might be used to enhance the luminosity of future linear colliders. However, its utility for this purpose depends largely on the potential backgrounds that may be induced by the insertion of such a device in the interaction region of the detector. In this note we identify different sources of such backgrounds, calculate their event rates from the elementary interaction processes, and evaluate their effects on the major parts of a hypothetical Next Linear Collider (NLC) detector. For plasma lens parameters which give a factor of seven enhancement of the luminosity, and using the NLC design for beam parameters as a reference, we find that the background yields are fairly high, and require further study and improvements in detector technology to avoid their impact.

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