The Soviet orbital observatory GRANAT was launched in December 1989 and
was operational till November 1998. One of the main instruments
of the observatory was the French-Soviet hard X-ray coded mask telescope SIGMA
(Paul et al.1 1991, Adv.Space Res., 11, 279). It was the first
space telescope that used coded aperture technique for reconstruction of
sky images in hard X-rays (35-1300 keV). The angular
resolution of the telescope was approximately 12' and the accuracy of a source
localization is approximately 2-3'.<p>
SIGMA discovered numerous interesting hard X-ray sources including
GRS 1758-258, which is located
only 40' from bright soft X-ray source GX 5-1. It
detected hard X-ray flux from X-ray burster A1742-294, which is very
near to bright black hole binary 1E1740.7-2942. SIGMA set an upper
limit on the hard X-ray flux of from the central supermassive black hole in
our Galaxy.<p>
During the period 1990-1998 SIGMA observed more that one quarter of the sky
with sensitivity better than 100 mCrab. The Galactic Center region
had the deepest exposure ( approximately 9 million sec), with the
sensitivity to a source discovery (S/N > ~ 5) or approximately
10 mCrab.<p>
A list of all detected sources with references to publications
on them is presented in the paper of Revnivtsev et al. 2004, Astr. Lett. v.6.
In these survey images (40-100 keV) all performed observations are
averaged together. Transient sources that were discovered by
SIGMA may not visible in the averaged image.
<p>
This survey has some features that users should
keep in mind. The SIGMA telescope is a complicated instrument and
is strongly dominated by the accuracy of the background subtraction.
The presence of a very bright source in the field of view of the telescope
sometimes cannot be fully accounted for and as a result of it some 'ghost'
sources can appear. Such features can be seen in the regions near
very bright sources like Crab Nebula, Cyg X-1, Nova Per 1992,
Nova Mus 1991, Nova Oph 1993, and in the Galactic Center region.
In addition to its nominal field of view (~17x17 deg)
located around the optical axis of the telescope, SIGMA had another
window of relatively high transparency of its shield,
approximately 20-30&#176;; apart from the optical axis.
Becuase of this a very bright sources like Cyg X-1 can
cause non zero illumination of the SIGMA
detector if they are located approximately 20-30&#176;; from the optical axis.
The ring-like features caused by this effect, can be seen around Cyg X-1,
and Nova Per 1992.
<p>
The count rate of detected sources (or upper limits)
can be roughly translated into mCrab using the fact that
that Crab nebula gives the count rate approximately 2.8e<sup>-3</sup> cnts/s in the units, provided in 'flux' maps Provenance: High Energy Astrophysics Department,
Space Research Institute, Moscow, Russia; CEA, Centre d'Etudes de
Saclay Orme des Merisiers, France; Centre d'Etude Spatiale
des Rayonnements, Toulouse, France; F&eacute;d&eacute;ration de
Recherche Astroparticule et Cosmologie Universit&eacute; de Paris, France. This is a service of NASA HEASARC.
The GOALS sample consists of a total of 179 LIRGs (log (L_IR/L_sun) = 11.0-11.99) and 22 ultra-luminous infrared galaxies (ULIRGs: log (L_IR/L_sun) > 12.0) selected from the IRAS Revised Bright Galaxy Sample; these 201 objects comprise a statistically complete flux-limited sample of infrared-luminous galaxies in the local universe. The GOALS objects have been the subject of an intense multi-wavelength observing campaign, including space-based imaging and spectroscopy from Spitzer and Herschel.
The Great Observatories Origins Deep Survey (GOODS) aims to unite extremely deep observations from NASA's Great Observatories (Spitzer, Hubble and Chandra), ESA's Herschel and XMM-Newton, and the most powerful ground-based facilities. The aim is to survey the distant universe to the faintest flux limits across the broadest range of wavelengths.
GOODS aims to unite extremely deep observations from NASA's Great Observatories, the Spitzer Space Telescope, Hubble, and Chandra, ESA's XMM-Newton, and from the most powerful ground-based facilities, to survey the distant universe to the faintest flux limits across the broadest range of wavelengths. GOODS will survey a total of roughly 320 square arcminutes in two fields centered on the Hubble Deep Field North and the Chandra Deep Field South.
Great Observatories Origins Deep Survey (GOODS) Cutout Service
Short Name:
HST.GOODS.Cutout
Date:
05 Dec 2018 16:38:09
Publisher:
Space Telescope Science Institute Archive
Description:
GOODS aims to unite extremely deep observations from NASA's Great Observatories, the Spitzer Space Telescope, Hubble, and Chandra, ESA's XMM-Newton, and from the most powerful ground-based facilities, to survey the distant universe to the faintest flux limits across the broadest range of wavelengths. GOODS will survey a total of roughly 320 square arcminutes in two fields centered on the Hubble Deep Field North and the Chandra Deep Field South.
This survey is a mosaic of data taken at the low frequency T-array near Gauribidanur, India.
The data was distributed in the NRAO Images from the Radio Sky CD ROM.
<p>
The original 287x101 tiles had only 1 pixel overlap. To allow
higher order resampling, the data were retiled into two hemisphere
files of 1726x600 pixels with an overlap of 10 pixels.
<p>
The southernmost tiles were only 287x100 pixels. We assumed
that bottom row of these tiles (as compared with the others)
was truncated. Provenance: . This is a service of NASA HEASARC.
HERON used a dedicated 0.7-m telescope to image the haloes of 124 galaxies in the Local Volume to surface brightnesses of 28-30 mag/arcsec^2. The sample is primarily from the Two Micron All Sky Survey Large Galaxy Atlas and extended to include nearby dwarf galaxies and more distant giant ellipticals, and spans fully the galaxy color-magnitude diagram including the blue cloud and red sequence
The full-sky H-alpha map (6' FWHM resolution) is a composite of the
Virginia Tech Spectral line Survey (VTSS) in the north and the
Southern H-Alpha Sky Survey Atlas (SHASSA) in the south. Stellar
artifacts and bleed trails have been carefully removed from these maps.
The Wisconsin H-Alpha Mapper (WHAM) survey provides a stable zero-point
over 3/4 of the sky on a one degree scale. This composite map can be used
to provide limits on thermal bremsstrahlung (free-free emission) from
ionized gas known to contaminate microwave-background data. The map
(in Rayleighs; 1R=10<sup>6</sup>/4pi photons/cm<sup>2</sup>/s/sr), an error map, and a
bitmask are provided in 8640x4320 Cartesian projections as well as
HEALPIX (Nside 256, 512, and 1024) projections on the
<a href="https://faun.rc.fas.harvard.edu/dfink/skymaps/halpha/"> H-Alpha Full-Sky Map website</a>. Provenance: . This is a service of NASA HEASARC.
These data were generated at the HEASARC in 1994. Certain
gaps and streaks in the image have been fixed by interpolating
over the the gap. Typically these gaps are no more than a pixel
or two wide. A brief description of the satellite and the
data analysis follows. The map used in <i> SkyView </i>
is the map designated <tt> 322_15_tot_ecl_samp.img</tt> in the
<a href=ftp://legacy.gsfc.nasa.gov/heao1/data/a2/maps/heasarc_med_hed>
HEASARC FTP area</a>. Many other maps are available. These differ
in epoch, resolution, energy band,
coordinate system and projection, and sampling methods.
Details are given in the README file in the archive.
<p>
See Allen, Jahoda, and Whitlock (1994) for full details about the
available maps, their processing, and methods for converting the
map intensities into familiar physical units. Provenance: NASA, HEASARC. This is a service of NASA HEASARC.
HEAVENS images (ISDC - Data Centre for Astrophysics)
Short Name:
HEAVENS @ ISDC
Date:
09 Jul 2019 14:39:19
Publisher:
WFAU
Description:
SIAP Cutout service of the INTEGRAL ISGRI and JEM-X images.
HEAVENS provides analysis services for a number of recent and important
high-energy missions. These services will allow any user to perform
on-the-fly data analysis to produce straightforwardly scientific results
for any sky position, time and energy intervals without requiring
mission specific software or detailed instrumental
knowledge.