Data for these sources were obtained from the Vela 5B all-sky XC detector. The Vela 5B nuclear test detection satellite was part of a program run jointly by the Advanced Research Projects of the U.S. Department of Defense and the U.S.Atomic Energy Commission, managed by the U.S. Air Force. It was placed in a nearly circular orbit at a geocentric distance of ~118,000 km on 23 May 1969; the orbital period was ~112 hours. The satellite rotated about its spin axis with a ~64-sec period. The X-ray detector was located ~90 degrees from the spin axis, and so covered the celestial sphere twice per satellite orbit. Data were telemetered in 1-sec count accumulations. Vela 5B operated until 19 June 1979, although telemetry tracking was poor after mid-1976. The scintillation X-ray detector (XC) aboard Vela 5B consisted of two 1-mm-thick NaI(Tl) crystals mounted on photomultiplier tubes and covered by a 5-mil-thick beryllium window. Electronic thresholds provided two energy channels, 3-12 keV and 6-12 keV. In front of each crystal was a slat collimator providing a FWHM aperture of ~6.1x6.1 degrees. The effective detector area was ~26 sq-cm. Sensitivity to celestial sources was severely limited by the intrinsic detector background of ~36 cts/sec. The Vela 5B X-ray detector yielded ~40 cts/sec for the Crab, so 1 Vela ct/sec ~25 UFU~4.5E-10 ergs/sq-cm/sec in the 3-12 keV response band. This is a service provided by NASA HEASARC .
The Very Nearby Galaxy Survey (VNGS) is a Herschel Key Program (KPGT_cwilso01_1) to measure the emission spectrum from dust as well as important cooling lines from the gaseous interstellar medium in a sample of 13 very nearby galaxies (M51, M81, NGC2403, NGC891, M83, M82, Arp220, NGC4038/39, NGC1068, NGC4151, CenA, NGC4125, and NGC205). These galaxies have been chosen to probe as wide a region in galaxy parameter space as possible while maximizing the achievable spatial resolution and are already well-studied from X-ray and optical through to radio wavelengths. The far-infrared and submillimeter wavelengths probed by Herschel are absolutely crucial for understanding the physical processes and properties of the interstellar medium, the interplay between star formation and the interstellar medium in galaxies, and how they may depend on the wider galaxian environment.
Viking 1 Gas Exchange, Labeled Release, and Pyrolytic Release Data on Microfilm. These data, supplied by the investigation team, are on 16- mm microfilm and consist of descriptions of the commands that were sent to operate the three instruments, and tabulations of raw and reduced data returned. The command data include Mars time for each experiment sequence, the commands sent, predicted data points for each command file that were used to time tag the data when it came back from the instrument, and a summary of the major events of each command sequence.
Viking 2 Gas Exchange, Labeled Release, and Pyrolytic Release Data on Microfilm. These data, supplied by the investigation team, are on 16- mm microfilm and consist of descriptions of the commands that were sent to operate the three instruments, and tabulations of raw and reduced data returned. The command data include: Mars time for each experiment sequence, the commands sent, predicted data points for each command file that were used to time tag the data when it came back from the instrument, and a summary of the major events of each command sequence.
The VLA-A Texas Survey consists of a sample of objects extracted from the earlier Texas Interferometer 365 MHz Survey of radio sources covering a strip of sky from approximately -35.5 degrees declination to +71.5 degrees declination, and complete to flux densities of 0.25 Jy, with positional accuracies of ~1 arcsecond in RA and DEC. The sample is a subset of 71 sources drawn from the area of one optical Schmidt sky survey plate (covering ~6.5x6.5 degrees), Region S861, centered at approximately RA=190.640822109, DEC=-0.273834224277 (J2000), from the UK Schmidt SRC-J Survey. The Region S861 was initially chosen because it represented the combination of the deepest UK Schmidt plate material (the best optical survey material available at the time of the sample definition in 1989) and the highest galactic latitude, thereby emphasizing the extragalactic nature of the survey and also maximizing the likelihood of having more optical detections. Much more recently, the area of this plate has been covered by a number of important sky surveys including 2MASS, NRAO VLA FIRST, and the Sloan Digital Sky Survey (SDSS) which is now public. In particular, the availability of the Sloan Survey data provides 5-band ugriz color information at optical wavelengths, to depth of g,r=22.2.
VLA Faint Images of the Radio Sky at Twenty Centimeters (FIRST)
Short Name:
VLA-FIRST
Date:
23 Jul 2020 19:41:49
Publisher:
Space Telescope Science Institute Archive
Description:
Faint Images of the Radio Sky at Twenty-cm (FIRST) is a systematic survey of the North and South Galactic caps begun in 1993, using the NRAO Very Large Array (VLA) . Typical images are comprised of 1150x1550 1.8" pixels with 5" resolution. Source catalogs are also available including peak and integrated flux densities generated from the high resolution coadded images. The survey yields very accurate (<1 arcsec rms) radio positions of faint (>1 mJy/beam) compact sources. The areas observed were chosen to coincide with the Sloan Digital Sky Survey.
The VLA Low-Frequency Sky Survey (VLSS) is a 74 MHz continuum survey
covering the entire sky north of -30 degrees declination. Using the
VLA in BnA and B-configurations, it will map the entire survey region
at a resolution of 80" and with an average rms noise of 0.1 Jy/beam.
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This version include the data from the VLSS redux which increased the coverage
region slightly and substantially improved the data reduction. Details are in the
Lane et al. (2012) reference. Provenance: <b>VLSS Team: </b>R.A. Perley, J.J. Condon, W.D. Cotton (NRAO);
A.S. Cohen, W.M. Lane (NRC/NRL),
N.E. Kassim, T.J.W. Lazio (NRL),
W.C. Erickson (UMd). This is a service of NASA HEASARC.