Next: Bivariate polynomial interpolation Up: Echelle Spectra Previous: Removal of particle . The estimation of the background is one of the critical points in the reduction of echelle spectra for two reasons. ... diffuse light in the interorder space coming from adjacent orders. sky background spectrum . ... These locations are defined when performing the order definition (command DEFINE/ECHELLE or DEFINE/HOUGH ) and can be displayed by command LOAD/ECHELLE . ... Sky background definition . ...

ChangeLog for lcplot =============================== Version 1.18 - 2004-19-14 (NW) ------------------------------- Small changes introduced to allow lcplot to read the source RA and DEC from the headers correctly and thus plot the correct information on the the output plot (SPR-3282). ... Documentation also updated. ... Version 1.13.6 - 22-10-01 ----------------------- The test has been radically changed so that it doesn't test the .ps file, as these are never standard. ...

... Effects on signal to noise ratio! ... The Advanced Camera for Surveys (ACS) team at STScI has (Anderson & Bedin, 2010) that corrects for losses in charge how this algorithm changes the characteristics of the signal to eliminate unknown variables we use simulated images where explore a parameter space that includes background, object brightness, and position on the chip. ... Left shows an image with no CTE losses. ... Right is an image which has been corrected for CTE losses (FLC). ... PHOTOMETRY! ...

... When creating a mosaic from a set of individual frames, the correct background offset for each frame must be determined for proper matching. In this paper we describe a method for constructing a mosaic from a set of individual frames by applying a minimization technique. ... Typically these are frames with some known defect (see ? ... Determining which frames to exclude from the final mosaic is critical, since one bad frame can create background offset errors that propagate throughout the mosaic. ...

Next: *imcalc* - Obtain a Up: Calibration Previous: Exposure Map . Background maps are provided by the standard processing for all ROSAT and Einstein instruments. For the PSPC and IPC these are in three standard bands: soft, hard, and broad (Table 6.2). ... N.B.: ROSAT PSPC background maps in SASS 5-6 or higher are generated by smoothing a source-subtracted, exposure corrected image (see the ROSAT Data Products Guide). ... imcalc* - Obtain a background subtracted image for ROSAT PSPC Data . ...

T he Siding Spring Survey (SSS) is a Near-Earth Object search program that utilises the 0.5-m Uppsala Schmidt Telescope at Siding Spring Observatory, N.S.W., Australia. ... The mission of the Siding Spring Survey is to contribute to the inventory of near-earth objects (NEOs), or more specifically, the potentially hazardous asteroids (PHAs) and comets (PHOs) that may pose a threat of impact and thus harm to civilization. ... Based on the CSS Mission page . ... Siding Spring Survey Main Page . ...

... The J, H and K bands are characterized by a bright background, such a background is mainly due to the emission of atmospheric lines and of thermal radiation. ... If the source cover a large fraction of the slit, spectra off-source must be observed to adequately sample the sky background. ... The on chip integration time (time spent in each position of the slit) must not exceed 40 seconds in J and H bands and 60 seconds in K band. ... We suggest a sequence of 10 for each elementary integration time. ...

... Step 1: The magnetic field line tracing from the satellite position up to magnetic equatorial plane using IGRF magnetic field model. Step 2: Tracing back from the point (produced on the Step 1) to the Ionosphere (by using only dipole magnetic field) . ... The magnetic field line tracing from the satellite position up to the Ionosphere (the stop trace altitude 110 km) using Main (dipole) + Extraterrestrial magnetic field model (for example, Tsyganenko [1987], or [1989], or [1990] ) . ...

... PmWiki uses WikiStyles for styling text with color and other attributes. PmWiki 2.0 introduced the ability to control the styling further and to even place styles on blocks. ... This text is %color=red% red, %color=blue% blue, %% and normal (black). ... In addition, an author can define a style "shortcut" by using the define= property. For example, to define a style of %red% , one can use: . color=red define=mystyle% Here is some %mystyle% red text created using a style shortcut. ...

... Step 1: The Footprint position calculation by the magnetic field line tracing from the satellite position up to the Ionosphere by using IGRF + Tsyganenko [1987] magnetic field model (the stop trace altitude 110 km). Step 2: Tracing back from the Footprint (produced on the Step 1) to the dipole equatorial plane (by using only IGRF magnetic field model up to the geocentric distance 8 RE and dipole field model after this distance). ... Back to the description . ...

ALMA | ... In this section, we explain why we need to correct phase fluctuations and ALMA's strategy to do this. Rapid fluctuations will be corrected with water vapour radiometers (WVRs). The Cavendish Astrophysics Group was also a leading contributor to the ALMA prototype WVRs, which were put through their paces in tests at the Submillimeter Array (SMA). ... The Cavendish Astrophysics Group in partnership with the Onsala Space Observatory built two prototype WVRs for the ALMA project. ...

The visibility amplitude bias (there is also a closure phase bias, but this one is nominally corrected by the raw data averaging pipeline) is related to non-Poisson detector statistics due to after-pulsing, and to fixed pattern noise due to non-linearities in the modulation stroke. We determine the bias using so-called incoherent scans, which record data even though the delay lines are deliberately set away from the white light fringe. ... Averaging triple products.. ... Background data loaded. ...

Next: BASIC PROPERTIES Up: R CORONAE BOREALIS STARS Previous: INTRODUCTION . RCB stars are named after a star just visible to the naked eye in the constellation of Corona Borealis. RCrB was discovered by Edward Pigott (1797), an English amateur astronomer, who had been observing a star in the `Northern Crown' for over a decade. ... Since 1795, other RCB stars have been discovered and their properties have been carefully observed. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2013 March 25 . Planck Maps the Microwave Background . ... Visible in all directions, this cosmic microwave background is a complex tapestry that could only show the hot and cold patterns observed were the universe to be composed of specific types of energy that evolved in specific ways. ... About APOD | ... A service of: ASD at NASA / GSFC . ...

... To help find out, ESA launched the Planck satellite to map, in unprecedented detail, slight temperature differences on the oldest surface known -- the background sky left billions of years ago when our universe first became transparent to light. Visible in all directions, this cosmic microwave background is a complex tapestry that could only show the hot and cold patterns observed were the universe to be composed of specific types of energy that evolved in specific ways. ... The Universe Nearby . ...

Arecibo Upgrade Notes INSTRUMENTAL POLARIZATION : POLARIZATION ISOLATION ERRORS IN STOKES PARAMETERS Jim Cordes Joe Lazio 22 May 1996 Summary The purpose of this memo is to: 1 demonstrate how polarization isolation is related to errors in Stokes parameters ; 2 estimate a tolerable level of errors in Stokes parameters due to amplitude and ... There we had a level of cross coupling that gave about 10 errors in Stokes parameters. ...

... 14.1 Foreground color: the 'color' property . ... 14.2.1 Background properties: 'background-color' , 'background-image' , 'background-repeat' , 'background-attachment' , 'background-position' , and 'background' . ... Background properties are not inherited, but the parent box's background will shine through by default because of the initial 'transparent' value on 'background-color' . ... BODY { background: white url("pendant.gif"); background-repeat: repeat-y; background-position: center; } . ...

A primitive guider for Agile that works from science images. The guider is primitive because the guide loop is in TUI instead of in the hub where it belongs. ... Specify a guide star (set Star Pos and Centroid Rad ) one of two ways: . ... Then for every Agile image the guider will try to centroid a star at Star Pos and offset the telescope (using boresight offsets) to center the star at that position. ... The guider never modifies any entry field (Star Pos and Centroid Rad) unless Find is checked. ...

... Corresponding authors will receive an e-mail with a PDF file of paged proof for checking and correction. The file can be read and edited using Adobe Acrobat Reader (version 9 and higher) which can be free downloaded via the Internet ( http://get.adobe.c om/reader/ ). ... You can use text correction tools to make corrections (after selecting the necessary text fragment). ... For users of Adobe Reader 9: . ... to insert text without replacing the existing text, use the "Insert text at cursor" tool. ...

... Dr. Rodrigues, M1 group, Spain, has pointed out the confusion in identification of SN 1998ar in NGC 2916. ... I have measured the locations of point-like sources around NGC 2916 with DSS-1 image and 5 GSC stars. ... The magnitude of this star is estimated as 15.5 mag or so on DSS1 image. ... Star C seems to be dimmer than Star B, and comparing GSC 14.8 mag star and fainter neighbouring stars, its magnitude is about 1.5 mag dimmer than GSC 14.8 mag star; which tells that SN was about 16.3 mag. ...