VizieR Online Data Catalog: Rotational velocities of M33 (Kam+, 2017)

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Résumé

The primary observations for this study were made with the Synthesis Telescope (ST) at the Dominion Radio Astrophysical Observatory (DRAO). This telescope is an east-west interferometer consisting of seven dishes (~9m diameter) spaced variously across a baseline range of 13-617m. At 1420MHz, the longest baseline achieves a synthesized half-power beam width of 49''(EW) by 49''/sinδ(NS) with uniform weighting, although in the HI line we use a Gaussian taper in the u,v plane to increase the sensitivity of each velocity channel at the slight expense of resolution (58"*58"/sinδ).

Observations of M33 consist of Stokes I, Q, U, and V made in a 30MHz continuum band centered at 1420MHz (λ21cm), Stokes I in a 2MHz band at 408MHz (λ74cm), and 256 channels within a 2MHz band centered on the HI line. For this study we use only the HI data products; future studies will present the total power and polarized radio emission from M33. The datacube velocity resolution is 2.64km/s at 21cm, and each channel is ∆V=1.65km/s wide. The band was centered on a heliocentric velocity of VHEL=-180km/s. The measured noise per channel is ~12-13mJy/beam or ∆TB~1.1K in the elliptical synthesized beam (58"*114"). To increase sensitivity to the faint outermost HI disk of M33, a total of six full-synthesis pointings on and around the galaxy were observed and mosaiced together (on 09/29/08, 11/05/08, and 12/04/08).

Mots-clés

Physics, Rotational dynamics, Computer science, Astronomy, Geodesy, Geography