[tel-00726959, v1] Caractériser le milieu interstellaire ... - HAL - INRIA

J. Pety and N. Rodríguez-Fernández: Revisiting the theory of interferometric wide-field synthesistel-00726959, version 1 - 31 Aug 2012θ fwhm /δα s ) for different uv distances (in units of d prim ). We seethat we derive a 1% accuracy at all u when we sample the imageplane at a rate of 5 dumps per primary beam. However getting a0.1% accuracy needs quite high sampling rates (about 15). Thismust be compared with the accuracy of knowledge of B.We note that if a better accuracy is needed than the oneachievable with the highest sampling rate, it is in theory possibleto replace in the correlator software the rectangle apodizingfunction by another function which falls more smoothly. Toavoid the loss of sensitivity inherent to the use of such an apodizingfunction (by throwing away data at the edges of the time intervalof integration), would require, for instance, to half-overlapthe integration intervals. This would imply more book-keepingin the correlator software and some noise correlation betweenthe measured visibilities.ReferencesBevington, P. R., & Robinson, D. K. 2003, Data Reduction and Error AnalysisFor the Physical Sciences, 3rd edn. (McGraw-Hill)Bhatnagar, S., & Cornwell, T. J. 2004, A&A, 426, 747Bhatnagar, S., Cornwell, T. J., Golap, K., & Uson, J. M. 2008, A&A, 487, 419Bracewell, R. N. 2000, The Fourier Transform and its Applications, 3rd edn.(McGraw-Hill)Clark, B. G. 1980, A&A, 89, 377Cornwell, T. J. 1988, A&A, 202, 316Cornwell, T. J., Holdaway, M. A., & Uson, J. M. 1993, A&A, 271, 697Cornwell, T. J., Golap, K., & Bhatnagar, S. 2008, IEEE Journal of SelectedTopics in Signal Processing, 2, 647Cotton, W. D., & Uson, J. M. 2008, A&A, 490, 455D’Addario, L. R., & Emerson, D. T. 2000, On-The-Fly Fringe Tracking, ALMAmemo, 331Ekers, R. D., & Rots, A. H. 1979, in Image Formation from Coherence Fucntionsin Astronomy, ed. C. van Schoonedveld (D. Reidel), IAU Proc., 49, 61Frater, R. H., & Docherty, I. S. 1980, A&A, 84, 75Goldsmith, P. F. 1998, Gaussian Beam, Quasioptical Propagation andApplications (IEEE Press)Gueth, F., Guilloteau, S., & Viallefond, F. 1995, in The XXVIIth YoungEuropean Radio Astronomers Conference, ed. D. A. Green, & W. Steffen,8Hamaker, J. P., Bregman, J. D., & Sault, R. J. 1996, A&AS, 117, 137Högbom, J. A. 1974, A&AS, 15, 417Holdaway, M. A., & Foster, S. M. 1994, On-The-Fly Mosaicing, ALMA memo,122Mangum, J. G., Emerson, D. T., & Greisen, E. W. 2007, A&A, 474, 679Narayan, R., & Nityananda, R. 1986, ARA&A, 24, 127Pety, J., Gueth, F., & Guilloteau, S. 2001, Impact of ACA on the Wide-FieldImaging Capabilities of ALMA, ALMA memo, 398Press, W. H., Teukolsky, S. A., Vetterling, W. T., & Flannery, B. P. 1992,Numerical Recipes in C, 2nd edn. (Cambridge University Press)Rodríguez-Fernández, N. J., Pety, J., & Gueth, F. 2008, Single-dish observationand processing to produce the short-spacing information for a millimeterinterferometer, IRAM memo, 2008-2Rodríguez-Fernández, N. J., Pety, J., & Gueth, F. 2009, Imaging ofinterferometric On-The-Fly observations: Context and discussion of possiblemethods, IRAM memo, 2009-2Sault, R. J., Hamaker, J. P., & Bregman, J. D. 1996a, A&AS, 117, 149Sault, R. J., Staveley-Smith, L., & Brouw, W. N. 1996b, A&AS, 120, 375Sault, R. J., Bock, D. C.-J., & Duncan, A. R. 1999, A&AS, 139, 387Schwab, F. R. 1984, AJ, 89, 1076Sramek, R. A., & Schwab, F. R. 1989, Synthesis Imaging in Radio Astronomy,Conf. Ser. (ASP), 117Thompson, A. R., Moran, J. M., & Swenson, G. W. J. 1986, Interferometry andSynthesis in Radio Astronomy (John Wiley & Sons)Page 21 of 21