This site will provide support to GALEX guest investigator programs, FUV & NUV obtained simultaneously using dichroic beam splitter also acting as a field. NUV: Flux [erg sec-1 cm-2 Å-1] = x x CPS. To convert from GALEX counts per second (CPS) to magnitudes in the AB system (Oke ): FUV: mAB . GALEX uses microchannel plate detectors to obtain direct images in the near-UV (NUV) and far-UV (FUV) and a grism to disperse light for low resolution.

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[astro-ph/] Panoramic GALEX FUV and NUV imaging of M31 and M33

These included a number of redelivered GR6 data additional visits and associated coadds from onwardsalong with new tiles within GR7, which span approximately from Jan. The two instrument modes used for astronomical observations are imaging aka direct and grism. A sample of the GR7 subdeliveries are: For each sub-visit the spiral dither pattern is restarted. This was in contrast to the traditional boresight dither, known as the “petal pattern”, and to AIS modes in which the spacecraft hovered over single sky pointings and was reduced to a low voltage non-observing state when orienting between pointings.

Its reflecting entrance side corrects the FUV channel, whereas the exit side cancels the entrance side effects and brings in the required amount of correction for the NUV channel.

For faint UV observations, the combination of low background zero read noise and high red rejection that these detectors possess represents a favorable trade-off against the superior QE and field flatness of more conventional CCD detectors. The instrument is a 50 cm Ritchey-Chretien telescope with selectable imaging window or objective grism feeding a pair of detectors simultaneously with a multilayer dichroic fkv.


Since aglex sources move on the detector throughout an exposure, the pipeline software corrects each time-tagged photon to common sky coordinates based on the satellite aspect solution. Increased coverage of the Kepler field. A cross section of the instrument is shown in Figure 2 below. There is a catalog based on visits and another catalog based on coadds.

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Ba seline survey sensitivities typically specified as 5 sigma for imaging and 10 sigma for spectroscopy are given in Table 1, above. GALEX data products include a series of all sky surveys and deep sky surveys in the imaging mode, and partial surveys in the near and far UV spectroscopic modes. The instrument integration, central processor, thermal control, test and project management were all provided by the Jet Fiv Laboratory Pasadena, CA.

This edge yields an additional factor of rejection of the NUV zodiacal light background above and beyond the natural CsTe galez photocathode cut-off. A high-level description of data retrieval modes is provided on the Getting Started page.

Users can familiarize themselves with GALEX data products by selecting, browsing, and downloading them from several search forms accessible from the Search and Retrieval tab on this page. Figure 3 above shows time-series telemetry plots for a set of observations described in Table 2. The top horizontal lines in red, green and orange, indicates eclipse, day and SAA periods respectively. Diamond symbols are spaced every seconds 1 revolution every two minutes.

For these observations the smooth variation in count rate vs. Dashed Spectra for galaxies with varying burst history young to old.

Individual photons incident at the cathode set off an isolated avalanche of current inside parallel micron diameter microchannel plate MCP pores as they accelerate through a few-keV field. This switching is performed by exchanging the grism with a low power plano-convex CaF2 imaging window.


The grism and the imaging window positional tolerances are loose because they are dioptric components with only a low power. This low power fhv optimized to correct for the axial chromatism of all the transmissive elements. Each target consists either of a single pointing single visit observation or multiple adjacent pointings sub-visit observations.

But scan mode was performed at a time when the mission was operating on both minimal staff and budget, so while nominal data products were produced, the calibration pipeline was not optimized to handle these data, and no additional scientific support was available.

By appropriately scaling the new flat fields measured in flight, we have maintained the original zero points with respect to the in-flight measurements of spectrophotometric standards. Its wedge angle is adjusted to correct for the coma induced in a converging beam, simultaneously for orders 2 and 1 gaoex of the FUV and NUV channels respectively.

Because GALEX records time-tagged photon positions with digitization that oversamples the instrumental PSF by a factor of 3—5the pipeline map accumulator can re-bin photon positions onto an idealized projection.

Chapter 1 – Instrument Overview

Volume [Gpc 3 ]. A summary of instrument optical specifications is presented in Table 1. Area [deg 2 ]. During any visit or sub-visit observation the spacecraft attitude is controlled in a tight, spiraled dither.