The European Space Agency's satellite COS-B was dedicated to gamma-ray astronomy in the energy range 50 MeV to 5 Gev and carried a single spark chamber telescope with approximately a 20 degree field of view. COS-B operated in a highly eccentric polar orbit with apogee around 90000 km between 17 August 1975 and 25 April 1982. During this operational lifetime, COS-B made 65 observations, 15 of which were devoted to high (>20 deg) galactic latitudes. The COSBRAW database table is a log of the 65 COS-B observation intervals and contains target names, sky coordinates start times and other information taken from the final COS-B database produced by ESA in 1985. This final database consisted of three basic datasets: `OBSLI`, a dataset describing each observation period, typically a month; `OURLI`, a dataset describing each uninterrupted observation interval, lasting between 10 minutes and 10 hours; and `GAMLI`, a dataset containing records for each accepted gamma-ray photon. These three data sets were combined into FITS format images at NASA/GSFC. The images were formed by making the center pixel of a 1024 x 1024 pixel image correspond to the RA and DEC given in the `OBSLI` file. Each photon's RA and DEC was converted to a relative pixel in the image. This was done by using Aitoff projections. All the raw data from these three COS-B files are now stored in 65 FITS files accessible with BROWSE software in the database COSBRAW. The images can be accessed and plotted using XIMAGE and other columns of the FITS file extensions can be plotted with the FTOOL FPLOT. This is a service provided by NASA HEASARC .
Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS)
Short Name:
CANDELS
Date:
12 Feb 2020 21:03:03
Publisher:
Space Telescope Science Institute Archive
Description:
CANDELS is designed to document the first third of galactic evolution from z = 8 to 1.5 via deep imaging of more than 250,000 galaxies with WFC3/IR and ACS. It will also find the first Type Ia SNe beyond z greater than 1.5 and establish their accuracy as standard candles for cosmology. Five premier multi-wavelength sky regions are selected; each has multi-wavelength data from Spitzer and other facilities, and has extensive spectroscopy of the brighter galaxies. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to 109 solar masses out to z ~ 8.
Cosmic Background Explorer DIRBE Annual\ Average\ Map
Short Name:
COBE
Date:
10 May 2024
Publisher:
NASA/GSFC HEASARC
Description:
The DIRBE Project Data Sets cover the whole sky and provide photometric data
in 10 bands ranging in wavelength from 1.25 to 240 microns. SkyView has supported
three maps: an early averaged map including including zodiacal and
Galactic components (COBE DIRBE (OLD)), a more recent cleaner version of
that data (COBE DIRBE/AAM) and a map with the zodaical light subtracted out
(COBE DIRBE/ZSMA). The early data is no longer supported. Please contact us if you
want access to these data.
<P>
Detailed descriptions of the DIRBE, the data processing, and the data products
are given in an Explanatory Supplement. A Small Source Spectral Energy Distribution
Browser can be used to assess the visibility of an unresolved or small extended source
in the DIRBE data and see its spectral energy distribution. As noted in section
5.6.6 of the Explanatory Supplement, the DIRBE Time-ordered Data are required to
derive definitive point source fluxes.
<p>
These maps provide an estimate of the infrared intensity at each pixel and
wavelength band based on an interpolation of the observations made at
various times at solar elongations close to 90&#176;;.
<P>
These COBE DIRBE maps are a combination original ten band passes with the following wavelengths:
<UL>
<LI>Band 1 - 1.25 &#181;;m
<LI>Band 2 - 2.2 &#181;;m
<LI>Band 3 - 3.5 &#181;;m
<LI>Band 4 - 4.9 &#181;;m
<LI>Band 5 - 12 &#181;;m
<LI>Band 6 - 25 &#181;;m
<li>Band 7 - 60 &#181;;m
<li>Band 8 - 100 &#181;;m
<li>Band 9 - 140 &#181;;m
<li>Band 10 - 240 &#181;;m
</ul>
<p>
The default two dimensional array uses Band 8 (100 &#181;;m).
<P>
The COBE DIRBE/Annual Average Maps (AAM) is the cumulative weighted
average of the photometry. This average is calculated using the
weighted number of observations from each Weekly Averaged Map
( WtNumObs from the Weekly Averaged Map) as the weight, such that
annual_average =sum( weekly_average * weekly_weight )/ sum( weekly_weight )
<p>
COBE DIRBE/Zodi-Subtracted Mission Average (ZSMA) Skymap represents
the extra-Solar system sky brightness. It is the average
residual map that results after the modelled interplanetary dust (IPD) signal
is subtracted from each of the DIRBE Weekly Skymaps from the cryogenic mission.
Individual weekly residual maps can be reconstructed from the data supplied in
the DIRBE Sky and Zodi Atlas (DSZA). Provenance: COBE Team. This is a service of NASA HEASARC.
The COSMOS Archive serves data taken for the Cosmic Evolution Survey with HST (COSMOS) project, using IRSA's general search service, Atlas. COSMOS is an HST Treasury Project to survey a 2 square degree equatorial field with the ACS camera.
The CRABTIME database contains the Crab Pulsar Monthly Ephemeris covering the period from Feb 15 1982 (MJD=45015) to (close to) the present that was created Dr. Andrew Lyne and collaborators at Jodrell Bank Observatory. This database is periodically updated to include recent data as these become available. To assist astronomers, the HEASARC has created two new parameters which were not present in the original Jodrell Bank tables, the pulsar period and its first derivative, using the standard relations between period (P) and frequency 'Nu' (P=1./Nu) and their first derivatives (P_dot = -Nu_dot/Nu<sup>2</sup>). The assumed pulsar position used in the reductions is <pre> RA (1950.0) 05 31 31.406 DEC (1950.0) +21 58 54.391 RA (2000.0) 05 34 31.973 DEC (2000.0) +22 00 52.061 </pre> This HEASARC version of the "Jodrell Bank Crab Pulsar Timing Results, Monthly Ephemeris" is updated within one week of any changes to the tables available on the Web at <a href="http://www.jb.man.ac.uk/pulsar/crab.html">http://www.jb.man.ac.uk/pulsar/crab.html</a>. This is a service provided by NASA HEASARC .