Next: Sky Subtraction Up: Construction of Flat Previous: Standard construction . For a number of projects where very deep integrations and accurate flat fields are required, and the targets are point sources or much smaller than the frame size, the sky background itself can be used to calculate the flat field. ... Use STATISTICS/IMAGE to calculate the image median, and COMPUTE/IMAGE to divide by this to get the normalised flat field. ...

... The amount of energy encircled by an aperture used for stellar photometry will depend on both the aperture size, and also on any variations in the PSF with field position, time, etc. ... The differences in photometric magnitude between apertures with various radii (i.e. aperture corrections), and their mean and standard deviations for the F555W filter, are presented in Table 5.5 . ... Variations in the PSF with field position will, of course, cause a position dependence in the aperture corrections. ...

Magnetic field measurements onboard the Interball Tail spacecraft are carried out by the FM-3I instrument which consists of two flux-gate magnetometers covering two different ranges: [-200, +200] nT and [-1000, +1000] nT. Besides scientific goals, the FM-3I experiment data is used to perform the attitude control of the Interball Tail spacecraft. ... August 22, 1995 . ... October 18, 1995 . Top of the page . ... Back to the Interball Home Page . ...

... The improvement will be more pronounced in our crowded Wide Field Camera (WFC) images, and may be increased further through use of a more sophisticated method of combining the individual dithered images. Our analysis allows us to check for point spread function shape variations in the HST Planetary Camera (PC) field. ... In crowded field images, we are deriving information about the faint end of the luminosity function (LF) from the texture of the image background. ...

Program: GETVAL Purpose: Get image values at given positions in a set Category: UTILITY File: getval.c Author: M.G.R. Vogelaar Keywords: INSET= Give set (,subset): Maximum number of subsets is 1. ... The image values are formatted according the string entered in FORMAT= APPEND= Ok to append? ... The flag characters and their meanings are: - The result of the conversion is left- justified within the field. ... If the result of a conversion is longer than the field width, an asterisk is returned. ...

IBIS Data Analysis . ... IBIS . ... Flat Fielding - Introduction . The images obtained by IBIS will have intensity variations across the field of view that are not due to the solar image, but rather caused by instrumental effects that alter the observed intensity in each point of the field of view. ... IBIS Flat Fielding Techniques . ... Therefore, it is desirable to obtain the flat field measurements center on a point along the equator near the heliographic center of the solar disk. ...

... 09.11.2007 (VNY) Fixed a bug that could result in a crash of the task when processing crowded fields (SSC-SPR-3700); Restoring the omgsource flag when extracting the target spectrum: in the case when omgrism is called from the interactive tool omgsource the target spectrum shouldn't be extracted (fixing the SSC-SPR-3702); Added a parameter enabling the output of an additional region file that contains newly detected point-like sources (zero-order features); . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The low-resolution, Cassegrain mounted, FORS spectropolarimeter of the ESO Very Large Telescope is being extensively used for magnetic field surveys. Some of the new discoveries suggest that relatively strong magnetic fields may play an important role in numerous physical phenomena observed in the atmospheres as well as in the circumstellar environments of certain kinds of stars. ...

RFI Test - IVULOTO Softek TxPort Luis Quintero Arecib o Observatory 15 Oct 2012 1 Intro duction ETS Model 7405[1] probe No.904: · · · · · Electric field. ... Performance: Fig. 3. + 15ft coax cable This document shows RFI test (electric field only) description and results for the two (2) IVULOTO Softek TxPort units for the Visitor Center. ... Figure 4 shows the results for the test points 1 (top, power supply) and 2 (bottom, Softek TxPort) for the Unit 1 with the top cover of the enclosure removed. ...

The beam pattern and the polarization characteristics . of the radio telescope RATAN-600 . The Mueller matrix elements was computed via formulas [1]: . ... The BP were computed by the aperture method, proceeding from the fild distribution in the aperture of the primary mirror. The components of the main and cross-polarization components of the electric field in the vertical aperture of the primary mirror was computed in Frenel diffraction approximation. ...

Next: X--ray Quiet PMS Up: Contents Previous: Fits to Evolutionary . The X--ray selected PMS candidates may not constitute a complete list. The primary factor is the sensitivity limit, complicated by the vignetting in the field of the PSPC which was used to make the source list. ... In order to better understand the completeness of the X--ray data, photometry of every star in both regions was undertaken. ... The X--ray quiet sources are distributed evenly across the field (see Figure 8 ). ...

An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . THE HUBBLE DEEP FIELD . In December 1995, the Hubble Space Telescope, high above the Earth, focused on a tiny spot of dark sky for over 150 consecutive orbits. ... Here we see about a fourth of that "deep field" and it shows galaxies (and only galaxies) at many different distances. The farthest among these galaxies is estimated to be so far away, its light has taken over 10 billion years to reach us. ...

... First Results from the X-Ray and Optical Survey of the Chandra Deep Field South", 2001, ApJ, 551, 624 . ... New Results from the X-ray and Optical Survey of the Chandra Deep Field South: The 300ks Exposure", 2001, ApJ, 562, 42 . ... Chandra Deep Field South: the 1 Msec Catalog", 2002, ApJS, 139, 369 . ... HST Imaging in the Chandra Deep Field South: Multiple AGN Populations" , American Astronomical Society, 198th AAS Meeting, #74.10; Bulletin of the American Astronomical Society, Vol. 33, p.899 . ...

... OOF . ... OOF Index . ... OOF software . ... Fits up to fifth order . ... These are experimental data currently being analysed, not final documentation of research. ... Only fitting for Zernike orders up to and including 3rd to concentrate on finding possible off-axis aberrations. ... The results below show that when fitting for all Zernikes up to and including fifth order, the output maps vary greatly between pixels. As above, but fitting up to fifth order Zernike polynomial. ...

... This appartus will drop a mass from different heights. When the mass strikes the ground, some percentage of its original energy will be absorbed by the ground. ... The percentage of the energy which is absorbed by the surface on each "bounce" (EAS) . ... The impact velocity of the object will also be given at each bounce. ... Start= Drop the ball after Energy, Mass and EAS have been set; resume after step or pause has been selected . ... Reset = Reset experiment to intial values . ...

... We have compared visualized fields of GSC and USNO A1.0 catalog with unpublished photographic finding charts that were sent by L. Plaut to the compilers of the GCVS. ... 7-15 A9 --- GCVS GCVS or NSV name 17-25 F9.4 --- GSC GSC number 26 A1 --- NoteFlag *Nonstar (GSC) flag 28-29 I2 h RA2000GSC.h Hours RA (GSC), equinox 2000.0 31-32 I2 min RA2000GSC.m Minutes RA (GSC), equinox 2000.0 34-38 F5.2 s RA2000GSC.s Seconds RA (GSC), equinox 2000.0 40 A1 --- DE2000GSC.- ... Plaut, L., 1966, Bull. ...

... 368, 2007 Petr Heinzel, Ivan Dorotovi and Robert J. Rutten, eds. c Some Structural Prop erties of Solar Magnetic Fields B. Ioshpa, E. Mogilevskii and V. Obridko IZMIRAN, Troitsk, Moscow Region, Russia Abstract. We discuss some results of the study of spatial characteristics of solar magnetic fields. ... The global fractal numbers of space distribution of magnetic field on solar surface is closely connected with the mean absolute values of the longitudinal magnetic field for this surface. ...

... astro-ph . ... SAI VO . ... Whitespace-separated words are treated as AND ed. Show 10 50 100 articles per page in Full Compact mode . Normalized to: Fields, E. 4 article(s) in total . 61 co-authors, from 1 to 4 common article(s). ... Backus, Peter. Barott, Billy. Barott, William. ... Dreher, John. ... Fleming, Matt. Fleming, Scott W.. Forster, James R.. ... Law, Casey James. ... MacMahon, David. McMahon, Peter. ... Vitouchkine, Artyom. ... Williams, Peter K. G.. ...

Astronomy Picture of the Day . The Hubble Deep Field in Infrared . ... Credit: R. I. Thompson ( U. Arizona ), NICMOS , HST , NASA Explanation: Galaxies this faint have never been seen before. In 1996 the Hubble Space Telescope (HST) created one of the most famous pictures of modern astronomy, the Hubble Deep Field (HDF). ... Publications with keywords: Hubble space telescope - infrared - Hubble Deep Field . Publications with words: Hubble space telescope - infrared - Hubble Deep Field . ...

TUI supports the following offsets: . Object Arc offset by a given amount on the sky (i.e. along the arc of a great circle). ... Arc offsets are useful for moving a different portion of your object or a different nearby object onto the boresight . ... Object Arc XY this is identical to an Object offset except that it has been rotated to align along the instrument x-y axes. ... This is just like the Calibration XY offset, except that it is typically cleared when you slew to a new object. ...