On the Magnetic Field Evolution in shell-like Supernova Remnants
In this paper we apply and discuss a method for the determination of the magnetic field (H) evolution in supernova remnants (SNRs) from radio luminosity at given frequency v to diameter (Lv - D) correlation. We assumed that H evolves as H ∞ D-δ, where D is the diameter of the remnant. A value δ <img border=0 width=20 height=15 src="../../../../../img/revistas/rmaa/v43n1/a2s1.jpg"> 1.2 is obtained under the equipartition assumption from the equations for revised equipartition calculation (REC) and by using the data sample from the nearby starburst galaxy M82. We try to investigate whether or not SNRs in M82 are in the equipartition state. This is done by comparison of our empirically obtained δwith the theoretical value expected for equipartition conditions. The inconsistency between the value obtained for equipartition conditions and adiabatic expansion (δ = 1.5) and the value empirically obtained herein can be explained mainly by the influence of sensitivity selection effects which tend to flatten the slope of the Lv - D relations for extragalactic samples.
| Main Authors: | , , |
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| Format: | Digital revista |
| Language: | English |
| Published: |
Universidad Nacional Autónoma de México, Instituto de Astronomía
2007
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| Online Access: | http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0185-11012007000100002 |
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| Summary: | In this paper we apply and discuss a method for the determination of the magnetic field (H) evolution in supernova remnants (SNRs) from radio luminosity at given frequency v to diameter (Lv - D) correlation. We assumed that H evolves as H ∞ D-δ, where D is the diameter of the remnant. A value δ <img border=0 width=20 height=15 src="../../../../../img/revistas/rmaa/v43n1/a2s1.jpg"> 1.2 is obtained under the equipartition assumption from the equations for revised equipartition calculation (REC) and by using the data sample from the nearby starburst galaxy M82. We try to investigate whether or not SNRs in M82 are in the equipartition state. This is done by comparison of our empirically obtained δwith the theoretical value expected for equipartition conditions. The inconsistency between the value obtained for equipartition conditions and adiabatic expansion (δ = 1.5) and the value empirically obtained herein can be explained mainly by the influence of sensitivity selection effects which tend to flatten the slope of the Lv - D relations for extragalactic samples. |
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