Observation Strategies . Saturation is a common problem for narrow band filter images of galaxy nuclei. Often the surface brightness of the emission line is estimated from ground-based images with 1" resolution; sometimes line fluxes are quoted for apertures several arcseconds in radius. However, at HST resolution, much of this flux may occur in a single unresolved spot at the galaxy nucleus, thus leading to saturated images. ...

... Let us first find out which way -- rise in spectral resolution with some loss in the S/N ratio or increase in the S/N ratio with a fixed spectral resolution -- is better for the purpose of reduction of equivalent width determination errors. ... N -- number of counts for 1 ? ... line equivalent width, . ... Thus if the spectral resolution is managed to be increased (i.e. to decrease )without loss in the number of counts falling at 1 ?, the equivalent width measurement error is then proportional to . ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope 20GHz Survey . ... Images . ... An Imaging Survey of the Northern Galactic H Emission with Arcminute Resolution . ... We present preliminary results from a high-resolution, high-sensitivity imaging survey of the northern galactic H emission. ... Our observations place stringent limits upon the contribution to the apparent microwave fluctuations from free-free emission in the galactic foreground...

... Flux density at 1 GHz (/Jy): 2720 . ... Optical: Fast knots and quasi-stationary flocculli, with many filaments at large radii, and NE `jet'. ... ADS . ... 1991, ApJ, 373, 146. ... NH 3 absorption and CO observations. ... 1995, ApJ, 440, 706. ... 1995, ApJ, 444, 244. gamma-ray observations. ... Anderson & Rudnick 1996, ApJ, 456, 234. ... 1999, ApJ, 518, 284. ... NRAO 12-m at 86 GHz (72": S=101?3.3 Jy) and 140 GHz (44": S=69.6?6.3 Jy), plus CO observations. ... 2001, ApJ, 547, L41. ...

... We will consider the rms, (K), for observations with a receiver of system temperature, T , frequency resolution, per polarization, and total integration time per observing cycle, . ... For ``in-band'' frequency switching, the line under investigation is always in the observing band. ... Position Switching or ``Out-of-Band'' Frequency Switching: Here the line is only observed for one half of the time, with noise being present all of the time. ...

... We present 5GHz high resolution VLA observations of 2,127 radio-- and X-ray--emitting sources found in both the Green Bank (GB) 5GHz radio catalog and the ROSAT All-Sky Survey (RASS). We report core flux densities and positions accurate to =-0.5". ... This table has 1861 rows and 9 columns giving: Catalog source name, RA and DEC (J2000), observation code, S/N ratio, VLA core flux density at 5 GHz (mJy), Green Bank flux density at 5 GHz (mJy), error in Green Bank flux density (mJy), and Notes. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... This is the first in a series of papers in which we describe and report the analysis of a large survey of Herbig Ae/Be stars in circular spectropolarimetry. Using the ESPaDOnS and Narval high-resolution spectropolarimeters at the Canada-France-Hawaii and Bernard Lyot Telescopes, respectively, we have acquired 132 circularly-polarised spectra of 70 Herbig Ae/Be stars and Herbig candidates. ...