... 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. ...

... Note: Click here a longer, much more comprehensive overview of the polar aurora . ... Magnetic Field . ... Aurora . ... 3b. Fritz Aurora . ... Electrons . ... Typical aurora (Dick Hutchinson ї) . In Alaska, Canada, Norway, Finland or northern Russia, on a clear night, a greenish glow is often seen in the sky, known as the "Northern Lights." ... Auroral light is produced at a height of about 100 km (60 miles) when fast electrons, arriving from space, slam into atoms and molecules of the atmosphere. ...

... Note: Click here a longer, much more comprehensive overview of the polar aurora . ... Magnetic Field . ... Aurora . ... 3b. Fritz Aurora . ... Electrons . ... Typical aurora (Dick Hutchinson ї) . In Alaska, Canada, Norway, Finland or northern Russia, on a clear night, a greenish glow is often seen in the sky, known as the "Northern Lights." ... Auroral light is produced at a height of about 100 km (60 miles) when fast electrons, arriving from space, slam into atoms and molecules of the atmosphere. ...

... HST . ... Data . ... HST Overview . ... Instrument Handbook . ... Use of ACQ/IMAGE mode automatically records and downlinks an image taken after the centroid is determined and HST is moved to that position. ... However, only point sources within about 0.5 arcsec of the aperture center have essentially all their light imaged, and so the photometric interpretation of a COS image can be inherently complex. ... For information on imaging strategies with COS see chapter 6 of the COS Instrument Handbook. ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Facilities . ATNF facilities . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... ATCA . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

Next: Radial velocity of the Up: Optical spectrum of IRAS04296 Previous: Observations and spectra reduction . ... However, molecular emission features are only very rarely observed in the optical spectra of PPNe. ... On the other hand, it is well known that cometary nuclei spectra show prominent Swan band emission. In both spectra of IRAS04296 we have discovered strong emission in the (0;0) and (0;1) bands of the Swan system of the molecule. ... Now consider the case of IRAS04296. ...

... NICS will be the only infrared instrument for the first light of the TNG; as a consequence, we decided to incorporate a sufficient degree of operation flexibility by providing the instrument with six different observing modes, three aimed at imaging and three at spectroscopy: . ... It will be possible to use the narrow band filters as order sorters; this will allow to perform high resolution long-slit spectroscopy in the wavelength ranges covered by the available narrow band filters. ...

... Galaxies 99 Cosmic background with model of cloudy interstellar medium Yu. ... Figure 1: Averaged spectrum of the cosmic background I f in frequency range 0.25 200 MHz for the Galactic poles. ... First interpretation of the cosmic noise background spectrum at broad band frequency range 0.25 200 MHz with a model of the cloudy interstellar medium ISM is presented here. ... Synthesized background spectra I f for regions of the Galactic poles at the frequency range 0.25 200 MHz is presented in Fig. ...

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...

... Observing . ... Solar Observing . ... April 3 (SUN) - Solar Observing, Central Park , Manhattan . ... APRIL'S SKY . .