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781. GTEE 0035 MHz Radio survey
ID:
ivo://nasa.heasarc/skyview/gtee
Title:
GTEE 0035 MHz Radio survey
Short Name:
GTEE
Date:
25 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
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.
782. Guide Star Catalog 2.3 Cone Search
ID:
ivo://archive.stsci.edu/gsc/gsc2.3
Title:
Guide Star Catalog 2.3 Cone Search
Short Name:
GSC23
Date:
13 Feb 2020 17:10:38
Publisher:
Space Telescope Science Institute Archive
Description:
The Guide Star Catalog II (GSC-II) is an all-sky optical catalog based on 1" resolution scans of the photographic Sky Survey plates, at two epochs and three bandpasses, from the Palomar and UK Schmidt telescopes. This all-sky catalog will ultimately contains positions, proper motions, classifications, and magnitudes in multiple bandpasses for almost a billion objects down to approximately Jpg=21, Fpg=20. The GSC-II is currently used for HST Bright Object Protection and HST pointing. Looking ahead, the GSC-II will form the basis of the Guide Star Catalog for JWST. This was constructed in collaboration with ground-based observatories for use with the GEMINI, VLT and GALILEO telescopes
783. Guide Star Catalog 1.1 Cone Search
ID:
ivo://archive.stsci.edu/gsc/gsc1.1
Title:
Guide Star Catalog 1.1 Cone Search
Short Name:
GSC11
Date:
13 Feb 2020 17:10:22
Publisher:
Space Telescope Science Institute Archive
Description:
The GSC-I catalog is an all-sky catalog of positions and magnitudes for approximately 19 million stars and other objects in the sixth to fifteenth magnitude range. The GSC is primarily based on an all-sky, single-epoch collection of Schmidt plates. For centers at +6 degrees and north, a 1982 epoch "Quick V" survey was obtained from the Palomar Observatory, while for southern fields, materials from the UK SERC J survey (epoch = 1975) and its equatorial extension (epoch = 1982) were used.
784. Guide Star Photometric ConeSearch
ID:
ivo://archive.stsci.edu/catalogs/GSPC2
Title:
Guide Star Photometric ConeSearch
Short Name:
GSP2 CS
Date:
13 Feb 2020 17:37:54
Publisher:
Space Telescope Science Institute Archive
Description:
The Guide Star Catalog (GSC) is a star catalog compiled to support the Hubble Space Telescope with targeting off-axis stars. GSC-II contains 945,592,683 stars out to magnitude 21. Photometric calibrations for GSC2 are available through this interface. All available catalogs are listed at http://archive.stsci.edu/vo/mast_services.html.
785. HADES RV Programme with HARPS-N at TNG. II.
ID:
ivo://CDS.VizieR/J/A+A/598/A26
Title:
HADES RV Programme with HARPS-N at TNG. II.
Short Name:
J/A+A/598/A26
Date:
21 Oct 2021
Publisher:
CDS
Description:
The distribution of exoplanets around low-mass stars is still not well understood. Such stars, however, present an excellent opportunity for reaching down to the rocky and habitable planet domains. The number of current detections used for statistical purposes remains relatively modest and different surveys, using both photometry and precise radial velocities, are searching for planets around M dwarfs. Our HARPS-N red dwarf exoplanet survey is aimed at the detection of new planets around a sample of 78 selected stars, together with the subsequent characterization of their activity properties. Here we investigate the survey performance and strategy. From 2700 observed spectra, we compare the radial velocity determinations of the HARPS-N DRS pipeline and the HARPS-TERRA code, calculate the mean activity jitter level, evaluate the planet detection expectations, and address the general question of how to define the strategy of spectroscopic surveys in order to be most efficient in the detection of planets. We find that the HARPS-TERRA radial velocities show less scatter and we calculate a mean activity jitter of 2.3m/s for our sample. For a general radial velocity survey with limited observing time, the number of observations per star is key for the detection efficiency. In the case of an early M-type target sample, we conclude that approximately 50 observations per star with exposure times of 900s and precisions of approximately 1m/s maximizes the number of planet detections.
786. HaloSat survey of southern Galactic halo
ID:
ivo://CDS.VizieR/J/other/NatAs/4.1072
Title:
HaloSat survey of southern Galactic halo
Short Name:
J/other/NatAs/4.
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Milky Way galaxy is surrounded by a circumgalactic medium (CGM) that may play a key role in galaxy evolution as the source of gas for star formation and a repository of metals and energy produced by star formation and nuclear activity. The CGM may also be a repository for baryons seen in the early universe, but undetected locally. The CGM has an ionized component at temperatures near 2x10^6^K studied primarily in the soft X-ray band. Here we report a survey of the southern Galactic sky with a soft X-ray spectrometer optimized to study diffuse soft X-ray emission. The X-ray emission is best fit with a disc-like model based on the radial profile of the surface density of molecular hydrogen, a tracer of star formation, suggesting that the X-ray emission is predominantly from hot plasma produced via stellar feedback. Strong variations in the X-ray emission on angular scales of ~10 degrees indicate that the CGM is clumpy. Addition of an extended, and possibly massive, halo component is needed to match the halo density inferred from other observations.
787. H{alpha} and [NII] survey in local 11 Mpc
ID:
ivo://CDS.VizieR/J/ApJS/178/247
Title:
H{alpha} and [NII] survey in local 11 Mpc
Short Name:
J/ApJS/178/247
Date:
21 Oct 2021
Publisher:
CDS
Description:
As part of a broader effort to characterize the population of star-forming galaxies in the local universe, we have carried out an H{alpha}+[NII] imaging survey for an essentially volume-limited sample of galaxies within 11Mpc of the Milky Way. This first paper describes the design of the survey, the observation, data processing, and calibration procedures, and the characteristics of the galaxy sample. The main product of the paper is a catalog of integrated H{alpha} fluxes, luminosities, and equivalent widths for the galaxies in the sample. We briefly discuss the completeness properties of the survey and compare the distribution of the sample and its star formation properties to other large H{alpha} imaging surveys. These data form the foundation for a series of follow-up studies of the star formation properties of the local volume, and the properties and duty cycles of star formation bursts in dwarf galaxies.
788. H{alpha} and UV SFR in the local volume
ID:
ivo://CDS.VizieR/J/ApJ/706/599
Title:
H{alpha} and UV SFR in the local volume
Short Name:
J/ApJ/706/599
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using a complete sample of ~300 star-forming galaxies within 11Mpc of the Milky Way, we evaluate the consistency between star formation rates (SFRs) inferred from the far ultraviolet (FUV) non-ionizing continuum and H{alpha} nebular emission, assuming standard conversion recipes in which the SFR scales linearly with luminosity at a given wavelength. Our analysis probes SFRs over 5 orders of magnitude, down to ultra-low activities on the order of ~10^-4^M_{sun}_/yr. The data are drawn from the 11Mpc H{alpha} and Ultraviolet Galaxy Survey (11HUGS), which has obtained H{alpha} fluxes from ground-based narrowband imaging, and UV fluxes from imaging with GALEX.
789. H{alpha} emitters at z=2.23
ID:
ivo://CDS.VizieR/J/MNRAS/416/2041
Title:
H{alpha} emitters at z=2.23
Short Name:
J/MNRAS/416/2041
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a narrow-band (H_2_S1, {lambda}_c_=2.121um, {delta}{lambda}=0.021um) imaging search with Wide Field Camera/United Kingdom Infrared Telescope for H{alpha} emitters (HAEs) around several potential signposts of rare (~10^-7^-10^-8^ comoving Mpc^-3^) overdense regions at z=2.23: an overdensity of quasi-stellar objects [QSOs; 2dF QSO Redshift Survey (2QZ) cluster], a powerful, high-redshift radio galaxy (HzRG) and a concentration of submillimetre galaxies (SMGs) and optically faint radio galaxies (OFRGs). In total, we detect 137 narrow-band emitter candidates down to emission-line fluxes of 0.5-1x10^-16^erg/s/cm^2^, across a total area of 0.56deg^2^ (2.1x10^5^ comoving Mpc^3^ at z=2.23) in these fields.
790. H-alpha Full Sky Map
ID:
ivo://nasa.heasarc/skyview/halpha
Title:
H-alpha Full Sky Map
Short Name:
HAlpha
Date:
25 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
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.

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