This services provides 1D spectra from DR5 of LAMOST (Large Sky Area
Multi-Object Fiber Spectroscopic Telescope) through SSAP;
data is served both in VO-standard SDM and, via datalink, the original
SDSS-inspired FITS described in
http://dr5.lamost.org/doc/data-production-description .
A collection of images of lensed quasars from various sources.
Included are images from Maidanak Observatory
(ivo://org.gavo.dc/maidanak/res/rawframes/siap), Apache Point
Observatory, from the MiNDSTEp project
(ivo://org.gavo.dc/danish/red/q), and from the Liverpool Robotic
Telescope (ivo://org.gavo.dc/liverpool/res/rawframes/q).
The LIFE Target Star Database contains information useful
for the planned `LIFE mission`_ (mid-ir, nulling
interferometer in space). It characterizes possible
target systems including information about stellar,
planetary and disk properties. The data itself is mainly
a collection from different other catalogs.
Note that LIFE's target database is living
data. The content – and to some extent even structure – of these
tables may change at any time without prior warning.
.. _LIFE mission: https://life-space-mission.com/
This collection includes optical monitorings of gravitationally lensed
quasars. The frames can be used to make light curves of quasar images
and field objects. From quasar light curves, one may measure time
delays and flux ratios, analyse variability and chromaticity, etc.
These direct analyses/measurements are basic tools for different
astrophysical studies, e.g., expansion rate of the Universe, mechanism
of intrinsic variability in quasars, accretion disk structure,
supermassive black holes, dark halos of galaxies (dust, collapsed dark
matter, smoothly distributed dark matter,...)
This service queries the catalog of radio sources from the LOFAR
Two-metre Sky Survey First Data Release (LoTSS-DR1) that have been
cross-matched with an optical or infrared counterpart. This data
release contains images and catalogs that characterise the
low-frequency radio emission in the region of the HETDEX Spring Field
(right ascension 10h45m00s to15h30m00s and declination 45◦00′00′′ to
57◦00′00′′). A total of 325,694 radio sources are detected in a region
covering 424 square degrees. The maps have a median sensitivity of 71
uJy/beam and a resolution of 6 arcsec. Optical counterparts for 71% of
the radio sources have been identified and where possible photometric
redshifts for these sources have been derived.
In this data release from the ongoing LOw-Frequency ARray (LOFAR)
Two-metre Sky Survey (LoTSS) we present 120-168 MHz images covering
27% of the northern sky. Our coverage is split into two regions
centred at approximately 12h45m +44°30′ and 1h00m +28°00′ and spanning
4178 and 1457 square degrees respectively. The images were derived
from 3,451 hrs (7.6 PB) of LOFAR High Band Antenna data which were
corrected for the direction-independent instrumental properties as
well as direction-dependent ionospheric distortions during extensive,
but fully automated, data processing. A catalogue of 4,395,448 radio
sources is derived from our total intensity (Stokes I) maps, where the
majority of these have never been detected at radio wavelengths
before. At 6′′ resolution, our full bandwidth Stokes I continuum maps
with a central frequency of 144 MHz have: a median rms sensitivity of
83 μ Jy/beam; a flux density scale accuracy of approximately 10%; an
astrometric accuracy of 0.2′′; and we estimate the point-source
completeness to be 90% at a peak brightness of 0.8 mJy/beam. By
creating three 16 MHz bandwidth images across the band we are able to
measure the in-band spectral index of many sources, albeit the error
on the derived spectral index is > ±0.2 which is a consequence of our
flux-density scale accuracy and small fractional bandwidth. Our
circular polarisation (Stokes V) 20′′ resolution 120-168 MHz continuum
images have a median rms sensitivity of 95 μ Jy/beam, and we estimate
a Stokes I to Stokes V leakage of 0.056%. Our linear polarisation
(Stokes Q and Stokes U) image cubes consist of 480 97.6 kHz wide
planes and have a median rms sensitivity per plane of 10.8mJy/beam at
4′ and 2.2mJy/beam at 20′′; we estimate the Stokes I to Stokes Q/U
leakage to be approximately 0.2%. Here we characterise and publicly
release our Stokes I, Q, U and V images in addition to the calibrated
uv-data to facilitate the thorough scientific exploitation of this
unique dataset. This service queries the Stokes I continuum mosaic
gaussian component catalogue.
