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UV-irradiated hydrogenated amorphous carbons (HACs) as carriersof the interstellar UV bump

Published online by Cambridge University Press:  13 February 2013

K.A.K. Gadallah ,
H. Mutschke  and
C. Jäger
K.A.K. Gadallah
Affiliation:
Astronomy Dpt., Faculty of Science, Al-Azhar University, Nasr City, PO Box, 11884 Cairo, Egypt;. e-mail: kamel.gadallah71@gmail.com Astrophysical Institute and University Observatory, FSU, Schillergässchen 2/3, 07743 Jena, Germany
H. Mutschke
Affiliation:
Astrophysical Institute and University Observatory, FSU, Schillergässchen 2/3, 07743 Jena, Germany
C. Jäger
Affiliation:
Institute of Solid State Physics, Friedrich Schiller University, Helmholtzweg 3, 07743 Jena, Germany

Abstract

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Hydrogenated amorphous carbons (HACs) are considered as laboratory analogues to cosmiccarbonaceous nanoparticles in the interstellar medium (ISM). The optical properties ofnano-sized HACs may be influenced by the UV processing. The variation of the internalstructure leads to dramatic changes in the spectral properties in the FUV-VIS range. Thisscenario can explain some astronomical features such as the interstellar UV bump at 4.6μm-1. The spectrum of HACs, irradiated by a dose of UVirradiation that corresponds to 21–33% of the average dose of the UV radiation in diffuseISM, exhibits a new band centered at 4.6 μm-1. This resultconfirms, for the first time, the suggestion by Mennella et al. (1996)that irradiated HACs might be considered as the carriers of the interstellar UV bump at4.6 μm-1. However, the amount of carbon needed to reproducethis band is higher than that available for interstellar carbon dust grains. So the idealstructure of irradiated HACs that would produce a band of sufficient strength has still tobe searched for.

References

Références

Allamandola, L.J., Tielens, A.G.G.M., & Barker, J.R., 1989, ApJS, 71 , 733 CrossRef
Cardelli, J.A., Clayton, G.C., & Mathis, J.S., 1989, ApJ, 345 , 245 CrossRef
Chhowalla, M., Wang, H., Sano, N., Teo, K.B., Lee, S.B., & Amaratunga, G.A., 2003, Phys. Rev. Lett., 90 , 155504 CrossRef
Draine, B.T., & Lee, H.M., 1984, ApJ, 285 , 89 CrossRef
Duley, W.W., & Seahra, S., 1998, ApJ, 507 , 874 CrossRef
Fitzpatrick, E.L., 1999, PASP, 111 , 63 CrossRef
Fitzpatrick, E.L., & Massa, D., 1990, ApJS, 72 , 163 CrossRef
Fitzpatrick, E.L., & Massa, D., 2007, ApJ, 663 , 320 CrossRef
Iida, Y., & Yeung, E.S., 1994, Appl. Spectrosc., 48 , 945 CrossRef
Jäger, C., Mutschke, H., Henning, T., & Huisken, F., 2008, ApJ, 689 , 249 CrossRef
Jenniskens, P., 1993, A&A, 274 , 653
Llamas-Jansa, I., Jger, C., Mutschke, H., & Henning, T., 2007, Carbon, 45 , 1542 CrossRef
Mennella, V., Brucato, J.R., Colangeli, L., & Palumbo, P., 1999, ApJ, 524 , L71 CrossRef
Mennella, V., Brucato, J.R., Colangeli, L., & Palumbo, P., 2002, ApJ, 569 , 531 CrossRef
Mennella, V., Colangeli, L., Bussoletti, E., Palumbo, P., & Rotundi, A., 1998, ApJ, 507 , L177 CrossRef
Mennella, V., Colangeli, L., Palumbo, P., Rotundi, A., Schutte, W., & Bussoletti, E., 1996, ApJ, 464 , L191 CrossRef
Ogmen, M., & Duley, W.W., 1988, ApJ, 334 , L117 CrossRef
Schnaiter, M., Mutschke, H., Dorschner, J., Henning, T., & Salama, F., 1998, ApJ, 498 , 486 CrossRef
Stecher, T.P., 1965, ApJ, 142 , 1683 CrossRef
Wada, S., Kaito, C., Kimura, S., & Tokunaga, A.T., 1999, Adv. Space Res., 24 , 523 CrossRef