GMOSAIC/GMAP - GALEX Target Field of View Simulator Karl Forster July 2007 ==================================================== The GMOSAIC plot shows a 5 x 5 degree region of the sky centered on the input coordinates. The field name and field center J2000 Equatorial and Galactic coordinates are shown above the plot. The GALEX field of view, circular with diameter 1.25 degrees, is centered on the input coordinates and is plotted in black. The background grayscale image shows the diffuse 100 micron emission (MJy/sr) taken from the COBE normalized IRAS cirrus maps of Schlegel, Finkbeiner, & Davis (1998). The maximum, minimum, and median 100 micron emission in the 5x5 region is given at the top of the page. The graysacle is on a linear scale from the minimum (white) to maximum (black) levels. I100 = 0.73 MJy/sr corresponds to: E(B-V) ~ 0.015 AV ~ 0.0465 nHI ~ 9 x 10^19 cm-2 I100 = 1.07 MJy/sr corresponds to: E(B-V) ~ 0.02 AV ~ 0.062 nHI ~ 1.2 x 10^20 cm-2 The positions of stars in the 5x5 degree target field are extracted from three catalogs: TD-1 (Thompson et al. 1978), Tycho2 (Hog et al. 2000), and SK2 (Myers et al. 2002). These positions are plotted using 2 symbols: Small green diamonds - stars with GALEX NUV fluxes estimated to be min_nuv cts/second (see below) and so pose no threat to GALEX detectors. Blue stars - Stars with GALEX NUV fluxes estimated to be >= min_nuv cts/s. The size of the stars indicates the estimated NUV count rate (on a logarithmic scale). The scale for the blue stars is given below the plot. Also shown are the regions around the blue stars (hashed blue circles) that must be avoided by the GALEX field of view to pass the star brightness limits: NUV Count Rate (counts/sec) / Distance from center of GALEX field of view (degrees) min_nuv / 0.75 50000 / 0.88 200000 / 1.00 500000 / 1.50 1000000 / 2.00 Stars that fail any of these brightness limits are plotted in red and the outer circle of the exclusion region is over-plotted with a red dashed line. min_nuv - this is a parameter that can be set when the plots are generated the limit is shown at the bottom of the plot as the first count rate where a violation can occur. The default value is 5000 cts/s but can be raised to 30000 cts/s. GMAP enhancements ----------------- When gmosaic is run using the gmap wrapper a number of additional features may appear on the plots: Positions that were observed to be so bright that they caused detector overcountrate shutdowns are indicated by red circles of 1.2 degree diameter with red/pink hatching. Red lines running NE-SW indicate NUV shutdowns, pink lines running NW-SE indicate FUV shutdowns. The Magellanic cloud exclusion regions will also appear as large red circles with vertical and horizontal lines on plots near the clouds. Planned targets in the field of view will be plotted as blue circles with 1.2 degree diameter and the target_id of the tiles will be printed centered on the blue circles. The positions of targets of interest (sometimes called science targets) can be plotted as red ellipses of varying sizes. REFERENCES Schlegel, D.J., Finkbeiner, D.P., & Davis, M. ApJ, 500, 525 (1998) "Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds" Thompson, G.I., Nandy, K., Jamar, C., Monfils, A., Houziaux, L., Carnochan, D.J., & Wilson, R. (1978) The Science Research Council, U.K. "A compilation of absolute stellar fluxes measured by the Sky Survey Telescope (S2/68) aboard the ESRO satellite TD-1", http://cdsweb.u-strasbg.fr/viz-bin/Cat?II/59B http://adsabs.harvard.edu/cgi-bin/bib_query?1982A&AS...49..427W Hog E., Fabricius C., Makarov V.V., Urban S., Corbin T., Wycoff G., Bastian U., Schwekendiek P., Wicenec A., Astron. Astrophys. 355, L27 (2000) The Tycho-2 Catalogue of the 2.5 Million Brightest Stars, http://www.astro.ku.dk/~erik/Tycho-2/ Myers et al. (2002) Goddard Space Flight Center, Flight Dynamics Division: SKY2000 Master Catalog, Version 4: http://mmfd.gsfc.nasa.gov/dist/generalProducts/attitude/ATT_SKY2KV1_aiaa_fnl.h