... Since the fast mode window is necessarily small, the source PSF fills much of the window (clearly evident for bright sources). ... As such, the source and background extraction apertures may be truncated by the window. ... While often there will be only one object in the image, one should check for spurious detections which could affect the analysis of the target source and also for missed sources or prominent objects in the window, which may contaminate the target. ...

Next: Code II: Unknown Up: Image Restorations of High Previous: Construction of Algorithms . ... The positions of the designated point sources ( ) must be given as well as initial amplitudes for and . ... The integrated flux of the point sources ( ) plus that of the distributed emission ( ) is constrained to equal that of the observed image ( ). ... This is investigated in Fig. 1 where all emission derives from point sources but only one - the brightest - is designated as such. ...

... Archives . ... keV vs keV [Eqn] . ... As mentioned before, background subtraction plays a big role in astrophysical analyses. For a variety of reasons, it is not a good idea to subtract out background counts from source counts, especially in the low-counts Poisson regime. What Bayesians recommend instead is to set up a model for the intensity of the source and the background and to infer these intensities given the data. ... C = Poisson(? ... Chandra Blog . ... SAMSI AstroStat Prog. ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

. This is a new popup window - close it when you are done . Submitted by Michael Brown on 11/01/2014 15:21:30 . M-15 - globular cluster in Pegasus . 10/27/14 . I made this image from 11 - 30-second individual exposures. It's surprising how overexposed the center is, even with such short exposures. I remember Al Takeda warning me about that with bright globulars! . Logon to post a follow-up comment or review comments from others . Copyright (c) Amateur Telescope Makers of Boston, Inc. About Us Contact Us

... This paper describes the main algorithms used by the Einstein Level One processing to create the exposure masks and the background maps for Einstein IPC images, and how these algorithms were recreated in the IRAF environment. Our goal was to recreate the algorithms used by the Level One Processing to create exposure masks and background maps for Einstein Image Proportional Counter (IPC) data (cf. sections 2.5 and 2.7 of Harnden et al. ...

... 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. ...

... 1Haynes+ A catalogue at 5 GHz of 915 sources in the Galactic plane is presented. Sources with a peak beam brightness temperature of at least 0.2 K above the surrounding background are included, except in confused regions; a point source of 0.2 K corresconds to 0.26 Jy. ... It was assumed that Hydra A was a point source with a peak flux density of 13 Jy at 5 GHz; this is equivalent to a mean beam brightness temperature of 10.0 K for a beamwidth of 4.1x4.4'. ...

. Comment on J1130-1449 . There are two dominant components in our image. Comparison with the 15 GHz image of Kellermann et al. (1998) reveals that the western component is brighter at the higher frequency, indicating that the brighter (eastern) component in our image may have a steep spectrum. VLBApls home page . Last modified: 16 Oct 2000

... Copyrightї1997 Bob Yen (byen@ix.netcom.com) (http://www.comet-track.com/hb/hb.html) . ... Information on Comet Hale-Bopp for the Non-Astronomer Hale-Bopp rotates about twice a day (3/14/97) . ... The Comet Observation Home Page was been selected to receive the Griffith Observatory Star Award for the week of February 2 - 8, 1997 for excellence in promoting astronomy to the public through the World Wide Web. ... Typically, about 1,000 individual users/computers access this page every day. ...

mom0 mom1 mom2 w50 w20 -------------------------------------------------------------------------------- ADD 216 07:31:39 -69:02:28 new -tidal_clo 0.114 11.7 1489.5 40.8 69.3 261.8 HIP 522 12:27:37 +01:34:14 HGcloud 0.491 29.7 1286.6 16.7 60.4 87.2 ZSS 102 16:18:46 -55:37:33 new -J1616-55e 0.124 3.7 399.5 7.0 30.5 43.3 HIP 827 17:11:57 -64:41:19 new -(VK- cloud 0.187 5.3 454.8 7.0 30.8 52.2 EXA 39 17:22:00 -59:45:00 new -(BK- ...

On 19/20 October 1995 we used GRIM II to attempt spectroscopy of the 2.3 micron CO absorption band in stellar clusters. ... Read Noise Our typical backgrounds in 60s were about 100 DN (about 500 e), and so for faint objects our noise is utterly dominated by the read noise of about 110 e. We can think of three ways to improve this situation: integrate longer; reduce the read noise; or implement multiple reads. ... Flats The quartz lamps were too dim for flats. ...

... Imagine that for every pixel in the color image, you take its luminance value (that's how bright it appears). ... In the end, you will have a histogram which counts how many times each luminance value appears in the image (that histogram can be used to analyze the distribution of the luminance values in the image). ... For the watermark effect, we want to use the same value that we used in the Stretch Contrast step, so that the lightest color will be in fact white (255), and nothing will get clamped...

... Science . ... Science Users Information > Data Handling and Products > Data Reduction FAQ > How can I run the pipeline when there are no bright objects in the individual image? ... Observing with ESO Telescopes . ... The default use of the visir_img_combine recipe of the VISIR pipeline is with the "ref" option set to false. ... The VISIR pipeline will create the combination of the nodded images using the ESO SEQ CUMOFFSETX and ESO SEQ CUMOFFSETY offset information in the fits file headers. ...

... In this activity, students will observe that the faintest stars which they can see in the sky are affected by many things: the adaptation of their eyes to the dark, the presence of clouds or haze, the time of year, and the presence of light pollution. General Information . ... After completing this activity, students should have a better understanding of the practical processes for dealing with the light pollution problem and with other environmental and societal issues. << previous page | ...

The Cosmic Microwave Background Radiation Temperature Work in groups of 2-4. ... Due 1999 April 15 In this laboratory exercise, you will use the radio telescope on the roof of Science B to measure the intensity of the Cosmic Microwave Background Radiation (CMBR). ... The output of the telescope when pointing at the sky will then be 2 Tsys = Trec + Tsky : The temperature of the sky can in principle arise from two sources, radiation from the atmosphere and radiation from outer space (the CMBR). ...

Astronotes Armagh Planetarium's Stellar Blog! ... Comets and Asteroids . ... Space Flight . ... November . ... By admin September 26, 2012 Posted in: Comets and Asteroids . Comet ISON is revealed.( ... Comet ISON.'s orbit and position on 25 September 2012.( ... The comet€а will reach its closest point to the Sun, perihelion in late November 2013.Then it is expected to whizz around the Sun a mere 1.1 million km above its surface making Comet ISON one of that class of comets called€а Sungrazers. ...

... Version: $Id: html-design.html,v 1.15 1994/11/26 19:53:43 connolly Exp $ . ... The HTML 2.0 Specification Review materials includes complete information on the HTML Working group of the IETF, the discussion of the HTML 2.0 specification, mailing list archive, and other supporting materials. ... JHU/APL's WWW HTML Developer's JumpStation - Page 1 . ... Gentle Introduction to SGML from the TEI guidelines. www-talk . ... There is also a hypertext archive. ... IETF Working group for HTML. www-html . ...

... Exposure Time Calculator (ETC) . ... Microstep (pattern) - a pattern of exposures at positions each shifted by a very small movement (<3 arcsec) from the reference position. ... A microstep pattern can be contained within each position of a jitter pattern. Jitter (pattern) - a pattern of exposures at positions each shifted by a small movement (<30 arcsec) from the reference position. ... Making a tile: Ysteps ; . ... Resulting Exposure time map for a filled tile of 6 pawprints (no jittering). ...

. Please standby and you will be automatically connected to the new location of the unframed Supernova page. Or, click on the link above. If you have questions or problems, please email me at David Bishop dbishop@vhdl.org . Last modified: Mon Aug 27 12:40:15 EDT 2001