Abstract:
Using the VLA in different configurations we have observed the galactic supernova remnants G7.7-3.7, G15.9+0.2, G18.8+0.3, G33.2-0.6, G46.8-0.3, G340.4+0.4, G340.6+0.3, G341.9-0.3, and G342.0-0.2 in the radio continuum at different frequencies. The current high quality observations enabled us to detect small-scale structures and weak diffuse emission in the interior of several remnants. We have recalculated fluxes, diameters and spectra, confirming previous estimates and improving them in some cases. At large scale the images were analized looking for traces of the influence of a non-uniform environment. In five out of the nine observed remnants, the brightest features occur on the side closer to the galactic plane. At fine scale, morphological properties were inspected together with spectral inhomogeneities in order to investigate whether the mechanisms that regulate the electron spectra can differ from the processes responsible for brightness enhancements. Our study shows that in general spectral variations coincide with brightness features, but the tendency of the relation is not uniform. Namely, G340.4+0.4 and G340.6+0.3 brighter regions have flatter spectra, while in G7.7-3.7, G15.9+0.2, and G341.9-0.3 the highest emissivity features are the steepest, and in G18.8+0.3 no spectral variation was found, regardless of the brightness variations. Polarization observations were performed in G7.7-3.7, finding that polarization occurs preferentially on the half of the shell facing the galactic plane. © 1996 American Astronomical Society.
Registro:
Documento: |
Artículo
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Título: | VLA observations of nine galactic supernova remnants |
Autor: | Dubner, G.M.; Giacani, E.B.; Goss, W.M.; Moffett, D.A.; Holdaway, M. |
Filiación: | Inst. Astronomia y Fis. del Espacio, C.C. 67, Suc. 28, 1428 Buenos Aires, Argentina National Radio Astronomy Observatory, Very Large Array, P.O. Box 0, Socorro, NM 87801, United States Department of Physics, New Mex. Inst. Mining and Technol., Socorro, NM 87801, United States
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Año: | 1996
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Volumen: | 111
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Número: | 3
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Página de inicio: | 1304
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Página de fin: | 1312
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DOI: |
http://dx.doi.org/10.1086/117875 |
Título revista: | Astronomical Journal
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Título revista abreviado: | Astron. J.
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ISSN: | 00046256
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Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046256_v111_n3_p1304_Dubner |
Referencias:
- Altenhoff, W.J., Downes, D., Good, L., Maxwell, A., Rinehart, R., (1970) A&AS, 1, p. 319
- Anderson, M., Rudnick, L., (1993) ApJ, 408, p. 514
- Angerhofer, P.E., Becker, R.H., Kundu, M.R., (1977) A&A, 55, p. 11
- Arnal, E.M., Dubner, G., Goss, W.M., (1993) RMxA&A, 26, p. 93
- Baars, J.W.M., Genzel, R., Pauliny-Toth, I.I.K., Witzel, A., (1977) A&A, 61, p. 99
- Caswell, J.L., Clark, D.H., (1975) AJPAS, 37, p. 57
- Caswell, J.L., Clark, D.H., Crawford, D.F., (1975) AJPAS, 37, p. 39
- Caswell, J.L., Haynes, R.F., Milne, D.K., Wellington, K.J., (1982) MNRAS, 200, p. 1143
- Caswell, J.L., Haynes, R.F., Milne, D.K., Wellington, K.J., (1983) MNRAS, 203, p. 595
- Clark, D.H., Caswell, J.L., Grenn, A.J., (1975) AJPAS, 37, p. 1
- Clark, D.H., Caswell, J.L., (1976) MNRAS, 174, p. 267
- Clark, D.H., Green, A.J., Caswell, J.L., (1975) AJPAS, 37, p. 75
- Condon, J.J., Broderick, J.J., (1985) AJ, 90, p. 2540
- Condon, J.J., Broderick, J.J., (1986) AJ, 91, p. 1051
- Condon, J.J., Broderick, J.J., Seielstad, G.A., (1989) AJ, 97, p. 1084
- Dickel, J., De Noyer, L., (1975) AJ, 80, p. 437
- Dickel, J.R., Milne, D.K., (1976) Australian J. Phys., 29, p. 435
- Dubner, G.M., Braun, R., Winkler, P.F., Gross, W.M., (1991) AJ, 101, p. 1466
- Dubner, G.M., Moffett, D.A., Goss, W.M., Winkler, P.F., (1993) AJ, 105, p. 2251
- Dubner, G.M., Giacani, E.B., Goss, W.M., Winkler, P.F., (1994) AJ, 108, p. 207
- Frail, D.A., Kassim, N.E., Weiler, K.W., (1994) AJ, 107, p. 1120
- Green, D.A., (1989) MNRAS, 238, p. 737
- Green, A.J., (1972), Ph.D. thesis, University of Sydney, Sydney, Australia; Kassim, N.E., (1988) ApJS, 68, p. 715
- Kassim, N.E., (1989) ApJS, 71, p. 799
- Kassim, N.E., (1989) ApJ, 347, p. 915
- Kassim, N.E., (1992) AJ, 103, p. 943
- Kovalenko, A.V., Pynzar', A.V., Udal'tsov, V.A., (1994) Astron. Rep., 38, p. 95
- Kovalenko, A.V., Pynzar', A.V., Udal'tsov, V.A., (1994) Astron. Rep., 38, p. 78
- Milne, D.K., (1987) AJP, 40, p. 771
- Milne, D.K., Caswell, J.L., Kesteven, M.J., Haynes, R.F., (1989) PASA, 8, p. 187
- Milne, D.K., Dickel, J.R., (1974) AJP, 27, p. 549
- Milne, D.K., Dickel, J.R., (1975) AJP, 28, p. 209
- Milne, D.K., Hill, E.R., (1969) AJP, 22, p. 211
- Milne, D.K., Roger, R.S., Kesteven, M.J., Haynes, R.F., Wellington, K.J., Stewart, R.T., (1986) MNRAS, 223, p. 487
- Milne, D.K., Caswell, J.L., Kesteven, M.J., Haynes, F., Roger, R.S., (1989) PASA, 8, p. 187
- Milne, D.K., Dickel, J.R., (1974) AJP, 27, p. 549
- Moffett, D.A., Reynolds, S.P., (1994) ApJ, 437, p. 705
- Mufson, S.L., Mc Collough, M.L., Dickel, J.R., Petre, R., White, R., Chevalier, R., (1986) AJ, 92, p. 1349
- Odegard, N., (1986) AJ, 92, p. 1372
- Pineault, S., Landecker, T.L., Routledge, D., (1987) ApJ, 315, p. 580
- Reich, W., (1982) A&A, 106, p. 314
- Saken, J.M., Fesen, R.A., Shull, M., (1992) ApJS, 81, p. 715
- Sato, F., (1979) AL, 20, p. 43
- Taylor, A.R., Wallace, B.J., Goss, W.M., (1992) AJ, 103, p. 931
- Velusamy, T., Becker, R.H., Seward, F.D., (1991) A.J., 102, p. 676
- Whiteoak, J.B.Z., (1993), Ph.D. thesis, University of Sydney, Sydney, Australia; Willis, A.G., (1973) AA, 26, p. 237
- Zealey, W.J., Elliot, K.H., Malin, D.F., (1979) A&AS, 38, p. 39
Citas:
---------- APA ----------
Dubner, G.M., Giacani, E.B., Goss, W.M., Moffett, D.A. & Holdaway, M.
(1996)
. VLA observations of nine galactic supernova remnants. Astronomical Journal, 111(3), 1304-1312.
http://dx.doi.org/10.1086/117875---------- CHICAGO ----------
Dubner, G.M., Giacani, E.B., Goss, W.M., Moffett, D.A., Holdaway, M.
"VLA observations of nine galactic supernova remnants"
. Astronomical Journal 111, no. 3
(1996) : 1304-1312.
http://dx.doi.org/10.1086/117875---------- MLA ----------
Dubner, G.M., Giacani, E.B., Goss, W.M., Moffett, D.A., Holdaway, M.
"VLA observations of nine galactic supernova remnants"
. Astronomical Journal, vol. 111, no. 3, 1996, pp. 1304-1312.
http://dx.doi.org/10.1086/117875---------- VANCOUVER ----------
Dubner, G.M., Giacani, E.B., Goss, W.M., Moffett, D.A., Holdaway, M. VLA observations of nine galactic supernova remnants. Astron. J. 1996;111(3):1304-1312.
http://dx.doi.org/10.1086/117875