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VLBA multi-epoch water maser observations towards Cepheus A

  • José M. Torrelles (a1), Nimesh A. Patel (a2), José F. Gómez (a3), Paul T. P. Ho (a2), Luiz F. Rodríguez (a4), Guillem Anglada (a2) (a5), Guido Garay (a6), Lincoln Greenhill (a2), Salvador Curiel (a7) and Jorge Cantó (a7)...

Abstract

We have carried out and recently reported VLBA multi-epoch water maser observations toward Cepheus A with an angular and velocity resolution of 0.5 mas and 0.2 km s−1, respectively. Some of the masers detected previously with the VLA (observations made with angular and velocity resolutions of 80 mas and 1.3 km s−1, respectively) are resolved now into linear/arcuate coherent “microstructures”. These structures, while smaller than the VLA beam, are 6-200 times the size of the VLBA synthesized beam. The morphology and the observed proper motions found in these structures imply three different centers of star formation activity in a region of ⋍ 0.3 radius (⋍ 200 AU). The most remarkable result from these observations is the discovery of an arc of water masers which is perfectly fitted by a circle to one part in a thousand. This arc is expanding and suggests a spherical “puff” of ejected material ejected 33 years ago from a protostar located 600 mas south of the radio jet HW2. This spherical ejection represents a very strong challenge for theoretical studies of star formation.

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References

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Cohen, R. J., Rowland, P. R., & Blair, M. M. 1984, MNRAS, 210, 425
Elitzur, M, Hollenbach, D. J., & McKee, C. F. 1992, ApJ, 394, 221
Furuya, R. S., Kitamura, Y., Wootten, H. A., Claussen, M. J., Saito, M., Marvel, K. B., & Kawabe, R. 2000, ApJ, 542, L135
Hughes, V. A., & Wouterloot, J. G. A. 1984, ApJ, 276, 204
Hughes, V. A., Cohen, R. J., & Garrington, S. 1995, MNRAS, 272, 469
Kaufmann, M. J., & Neufeld, D. A. 1996, ApJ, 456, 250
Lada, C. J., Blitz, L., Reid, M. J., & Moran, J. M. 1981, ApJ, 243, 769
Rodríguez, L. F., Garay, G., Curiel, S., Ramírez, S., Torrelles, J. M., Gómez, Y., & Velázquez, A. 1994, ApJ, 430, L65
Torrelles, J. M., Gómez, J. F., Rodríguez, L. F., Curiel, S., Ho, P. T. P., & Garay, G. 1996, ApJ, 457, L107
Torrelles, J. M., Gómez, J. F., Garay, G., Rodríguez, L. F., Curiel, S., Cohen, R. J., & Ho, P. T. P. 1998, ApJ, 509, 262
Torrelles, J. M., Patel, N. A., Gómez, J. F., Ho, P. T. P., Rodríguez, L. F., Anglada, G., Garay, G., Greenhill, L., Curiel, S., & Cantó, J. 2001a, ApJ, submitted [Paper I]
Torrelles, J. M., Patel, N. A., Gómez, J. F., Ho, P. T. P., Rodríguez, L. F., Anglada, G., Garay, G., Greenhill, L., Curiel, S., & Cantó, J. 2001b, Nature, 411 [Paper II]

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