Title | Obtaining High Precision HI Fluxes for Galaxies |
Authors | van Zee, Liese; Maddalena, Ronald J.; Haynes, Martha P.; Hogg, David E.; Roberts, Morton S. |
Bibcode | 1997AJ....113.1638v Search ADS ↗ |
Abstract | We present a method to obtain well-calibrated HI fluxes using standard continuum sources as absolute line flux calibrators. The method is applied to observations of 44 gas-rich dwarf galaxies with the Green Bank 43m telescope. The absolute flux calibration of the observations is accurate to 2%; our final error budget of 5% on the derived HI fluxes is conservative and predominately due to errors in baseline removal. The observations indicate that despite relatively small optical sizes ( ~ 2\arcmin), these systems have a large diffuse gas component. For 20 galaxies previously mapped at Arecibo, the median correction between a central Arecibo pointing and the observed flux density with the Green Bank 43m is 1.6. For 24 systems without known extended HI, the observed line fluxes reported here may be used in the future to search for the presence of a diffuse gas component through beam-matching experiments. |
Objects | 44 Objects Search NED ↙ |