A multi-frequency study of the spectral index distribution in the SNR CTB 80
We have conducted a study at radio wavelengths of the spectral behaviour of the supernova remnant (SNR) CTB 80. Based on an homogenised data set of integrated flux densities, we calculated for the whole SNR a radio index α = -0.36 ± 0.02. The shape of the global spectrum suggests absorption by ioniz...
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todo:paper_00046361_v440_n1_p171_Castelletti2023-10-03T14:00:13Z A multi-frequency study of the spectral index distribution in the SNR CTB 80 Castelletti, G. Dubner, G. ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Infrared radiation Light absorption Light emission Optical resolving power Radio ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Astrophysics We have conducted a study at radio wavelengths of the spectral behaviour of the supernova remnant (SNR) CTB 80. Based on an homogenised data set of integrated flux densities, we calculated for the whole SNR a radio index α = -0.36 ± 0.02. The shape of the global spectrum suggests absorption by ionized gas in the interstellar medium (ISM) along the line of sight. Spatial spectral variations across the SNR are investigated based on high-angular resolution data at 240, 324, 610, and 1380 MHz using different techniques. The three extended arms associated with this SNR show a clear indication of spectral steepening when moving outwards from the central nebula, with variations of up to Δα ∼ -0.9. However, while the spectral steepening is smooth along the eastern arm, the northern and soutwestern arms include locally flatter structures, which in all cases coincide with radio, IR and optical emission enhancements. We interpret this spectral property as the result of the combination of two different particle populations: aging relativistic electrons injected by PSR B1951+32 and particles accelerated at the sites where the SNR shock front encounters interstellar gas inhomogeneities. Concerning the central nebula, the angular resolution of the available database does not permit a detailed spectral study of the core region, i.e. the 45″ region around PSR B1951+32, where we can only confirm an average spectral index α = 0.0. The surrounding 8′ plateau nebula has an 〈α〉 ∼ -0.25, with a peak of α ∼ -0.29 coincident with a secondary maximun located at the termination of a twisted filament that trails to the east, behind the pulsar. © ESO 2005. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00046361_v440_n1_p171_Castelletti |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Infrared radiation Light absorption Light emission Optical resolving power Radio ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Astrophysics |
| spellingShingle |
ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Infrared radiation Light absorption Light emission Optical resolving power Radio ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Astrophysics Castelletti, G. Dubner, G. A multi-frequency study of the spectral index distribution in the SNR CTB 80 |
| topic_facet |
ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Infrared radiation Light absorption Light emission Optical resolving power Radio ISM: individual objects: CTB 80 ISM: supernova remnants Pulsar: individual: PSR B1951+32 Radio continuum: ISM Astrophysics |
| description |
We have conducted a study at radio wavelengths of the spectral behaviour of the supernova remnant (SNR) CTB 80. Based on an homogenised data set of integrated flux densities, we calculated for the whole SNR a radio index α = -0.36 ± 0.02. The shape of the global spectrum suggests absorption by ionized gas in the interstellar medium (ISM) along the line of sight. Spatial spectral variations across the SNR are investigated based on high-angular resolution data at 240, 324, 610, and 1380 MHz using different techniques. The three extended arms associated with this SNR show a clear indication of spectral steepening when moving outwards from the central nebula, with variations of up to Δα ∼ -0.9. However, while the spectral steepening is smooth along the eastern arm, the northern and soutwestern arms include locally flatter structures, which in all cases coincide with radio, IR and optical emission enhancements. We interpret this spectral property as the result of the combination of two different particle populations: aging relativistic electrons injected by PSR B1951+32 and particles accelerated at the sites where the SNR shock front encounters interstellar gas inhomogeneities. Concerning the central nebula, the angular resolution of the available database does not permit a detailed spectral study of the core region, i.e. the 45″ region around PSR B1951+32, where we can only confirm an average spectral index α = 0.0. The surrounding 8′ plateau nebula has an 〈α〉 ∼ -0.25, with a peak of α ∼ -0.29 coincident with a secondary maximun located at the termination of a twisted filament that trails to the east, behind the pulsar. © ESO 2005. |
| format |
JOUR |
| author |
Castelletti, G. Dubner, G. |
| author_facet |
Castelletti, G. Dubner, G. |
| author_sort |
Castelletti, G. |
| title |
A multi-frequency study of the spectral index distribution in the SNR CTB 80 |
| title_short |
A multi-frequency study of the spectral index distribution in the SNR CTB 80 |
| title_full |
A multi-frequency study of the spectral index distribution in the SNR CTB 80 |
| title_fullStr |
A multi-frequency study of the spectral index distribution in the SNR CTB 80 |
| title_full_unstemmed |
A multi-frequency study of the spectral index distribution in the SNR CTB 80 |
| title_sort |
multi-frequency study of the spectral index distribution in the snr ctb 80 |
| url |
http://hdl.handle.net/20.500.12110/paper_00046361_v440_n1_p171_Castelletti |
| work_keys_str_mv |
AT castellettig amultifrequencystudyofthespectralindexdistributioninthesnrctb80 AT dubnerg amultifrequencystudyofthespectralindexdistributioninthesnrctb80 AT castellettig multifrequencystudyofthespectralindexdistributioninthesnrctb80 AT dubnerg multifrequencystudyofthespectralindexdistributioninthesnrctb80 |
| _version_ |
1807316890518814720 |