TY - JOUR

T1 - Interferometer predictions with triangulated images

T2 - Solving the multiscale problem

AU - Brinch, Christian

AU - Dullemond, C. P.

PY - 2014

Y1 - 2014

N2 - Interferometers play an increasingly important role for spatially resolved observations. If employed at full potential, interferometry can probe an enormous dynamic range in spatial scale. Interpretation of the observed visibilities requires the numerical computation of Fourier integrals over the synthetic model images. To get the correct values of these integrals, the model images must have the right size and resolution. Insufficient care in these choices can lead to wrong results. We present a new general-purpose scheme for the computation of visibilities of radiative transfer images. Our method requires a model image that is a list of intensities at arbitrarily placed positions on the image-plane. It creates a triangulated grid from these vertices, and assumes that the intensity inside each triangle of the grid is a linear function. The Fourier integral over each triangle is then evaluated with an analytic expression and the complex visibility of the entire image is then the sum of all triangles. The result is a robust Fourier transform that does not suffer from aliasing effects due to grid regularities. The method automatically ensures that all structure contained in the model gets reflected in the Fourier transform.

AB - Interferometers play an increasingly important role for spatially resolved observations. If employed at full potential, interferometry can probe an enormous dynamic range in spatial scale. Interpretation of the observed visibilities requires the numerical computation of Fourier integrals over the synthetic model images. To get the correct values of these integrals, the model images must have the right size and resolution. Insufficient care in these choices can lead to wrong results. We present a new general-purpose scheme for the computation of visibilities of radiative transfer images. Our method requires a model image that is a list of intensities at arbitrarily placed positions on the image-plane. It creates a triangulated grid from these vertices, and assumes that the intensity inside each triangle of the grid is a linear function. The Fourier integral over each triangle is then evaluated with an analytic expression and the complex visibility of the entire image is then the sum of all triangles. The result is a robust Fourier transform that does not suffer from aliasing effects due to grid regularities. The method automatically ensures that all structure contained in the model gets reflected in the Fourier transform.

KW - Techniques: image processing

KW - Techniques: interferometric

U2 - 10.1093/mnras/stu524

DO - 10.1093/mnras/stu524

M3 - Journal article

AN - SCOPUS:84899821126

VL - 440

SP - 3285

EP - 3291

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

SN - 0035-8711

IS - 4

M1 - stu524

ER -