scholarly journals Euclid Space Mission: building the sky survey

2014 ◽  
Vol 10 (S306) ◽  
pp. 379-381 ◽  
Author(s):  
I. Tereno ◽  
C.S. Carvalho ◽  
J. Dinis ◽  
R. Scaramella ◽  
J. Amiaux ◽  
...  
Keyword(s):  
Physical Properties ◽  
Space Mission ◽  
Current Reference ◽  
Sky Survey ◽  
Reference Implementation

AbstractThe Euclid space mission proposes to survey 15000 square degrees of the extragalactic sky during 6 years, with a step-and-stare technique. The scheduling of observation sequences is driven by the primary scientific objectives, spacecraft constraints, calibration requirements and physical properties of the sky. We present the current reference implementation of the Euclid survey and on-going work on survey optimization.

Astrophysical Space Mission Astron-2 for an All-Sky Survey in the Ultraviolet Spectral Domain

2019 ◽  
Vol 53 (7) ◽  
pp. 560-566
Author(s):  
M. E. Sachkov ◽  
I. S. Savanov ◽  
B. M. Shustov ◽  
A. S. Shugarov ◽  
S. G. Sichevskij
Keyword(s):  
Space Mission ◽  
Spectral Domain ◽  
Sky Survey

scholarly journals A Galactic Population Census in Support of Astrometric Measurements

1995 ◽  
Vol 166 ◽  
pp. 211-215 ◽  
Author(s):  
M.A.C. Perryman
Keyword(s):  
Space Mission ◽  
Radial Velocities ◽  
Sloan Digital Sky Survey ◽  
Population Census ◽  
Sky Survey ◽  
Galactic Population ◽  
Recent Developments ◽  
Analysis System

A galactic counterpart of the Sloan Digital Sky Survey, consisting of two dedicated 2–3-m class telescopes (one in each hemisphere), could provide precisely those stellar data necessary to complement the information furnished by a future astrometric space mission: in particular, an automated acquisition and analysis system could provide spectral types, metallicities, and radial velocities of several tens of millions of stars down to about 15–16 mag. Such a dedicated spectroscopic stellar survey would provide considerably more information about the details of the stellar distribution within our Galaxy than is known at present. It is suggested that a galactic version of the Sloan Digital Sky Survey, utilising the GSC-II as an observing list, and capitalising on recent developments in multi-fibre spectroscopic survey capabilities, would be a timely initiative.

scholarly journals Radio-continuum observations of a giant radio source QSO J0443.8-6141

2013 ◽  
pp. 1-10 ◽  
Author(s):  
M.D. Filipovic ◽  
K.O. Cajko ◽  
J.D. Collier ◽  
N.F.H. Tothill
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Radio Source ◽  
Radio Galaxy ◽  
Radio Continuum ◽  
Linear Size ◽  
Sky Survey ◽  
Continuum Structure ◽  
Optical Surveys

We report the discovery of a giant double-lobed (lobe-core-lobe) radio-continuum structure associated with QSO J0443.8-6141 at z=0.72. This QSO was originally identified during the follow-up of a sample of ROSAT All Sky Survey sources at radio and optical frequencies. With a linear size of ~0.77 Mpc, QSO J0443.8-6141 is classified as a giant radio source (GRS); based on its physical properties, we classify QSO J0443.8-6141 as a FR II radio galaxy. High-resolution observations are required to reliably identify GRSs; the next generation of southern sky radio and optical surveys will be crucial to increasing our sample of these objects.

scholarly journals Nature of blackbody stars

2019 ◽  
Vol 623 ◽  
pp. A177 ◽  
Author(s):  
Aldo Serenelli ◽  
René D. Rohrmann ◽  
Masataka Fukugita
Keyword(s):  
Physical Properties ◽  
Trace Amount ◽  
Blackbody Radiation ◽  
Sloan Digital Sky Survey ◽  
Helium Atmosphere ◽  
Sky Survey ◽  
Pure Helium ◽  
Effective Temperatures ◽  
Selection Of ◽  
The Continuum

A selection of 17 stars in the Sloan Digital Sky Survey, previously identified as DC-class white dwarfs (WDs), has been reported to show spectra very close to blackbody radiation in the wavelength range from ultraviolet to infrared. Because of the absence of lines and other details in their spectra, the surface gravity of these objects has previously been poorly constrained, and their effective temperatures have been determined by fits to the continuum spectrum using pure helium atmosphere models. We computed model atmospheres with pure helium and H/He mixtures and used Gaia DR2 parallaxes that are available for 16 of the 17 selected stars to analyze their physical properties. We find that the atmospheres of the selected stars are very probably contaminated with a trace amount of hydrogen of −6 ≤ log(NH/NHe) ≤ −5.4. For the 16 stars with Gaia parallaxes, we calculate a mean stellar mass 0.606 ± 0.076 M⊙, which represents typical mass values and surface gravities (7.8 <  logg <  8.3) for WDs.

HCL1 and HCL2 - low mass star formation in violent and quiet environments

2018 ◽  
Vol 14 (S345) ◽  
pp. 333-334
Author(s):  
L. Viktor Tóth ◽  
Orsolya Fehér ◽  
Mika Juvela ◽  
Julien Montillaud ◽  
Sándor Pintér
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Physical Properties ◽  
Mass Star ◽  
External Effects ◽  
Star Forming ◽  
Radio Line ◽  
Sky Survey ◽  
Low Mass

AbstractRecently a large number of Galactic cold clumps were located with the Planck all-sky survey. Our radio line observations have revealed the distribution and physical properties of the interstellar medium in dozens of PGCC sources. Clumps can be affected by many external effects. HCL1 (a.k.a. L1251) and HCL2 (which contains also TMC-1) are examples of low mass star forming clouds in violent and quiet environments.

scholarly journals X-ray Morphology of Clusters of Galaxies

1992 ◽  
Vol 9 ◽  
pp. 205-209
Author(s):  
H. Böhringer ◽  
R.A. Schwarz ◽  
U.G. Briel ◽  
H. Ebeling ◽  
W. Voges
Keyword(s):  
Physical Properties ◽  
Galaxy Clusters ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Morphological Structure ◽  
Clusters Of Galaxies ◽  
X Ray ◽  
Sky Survey ◽  
First Results

AbstractThe ROSAT observatory with its high spatial resolution X-ray telescope is an ideal instrument for the study of clusters of galaxies. In the first part of the mission an All Sky X-ray Survey was conducted with ROSAT. Here we present first results of observations of Virgo, Perseus and some other clusters of galaxies from the All Sky Survey. These data illustrate the capabilities of the ROSAT observatory for studies of the morphological structure and physical properties of galaxy clusters.

scholarly journals Density and temperature of cosmic-web filaments on scales of tens of megaparsecs

2020 ◽  
Vol 637 ◽  
pp. A41 ◽  
Author(s):  
H. Tanimura ◽  
N. Aghanim ◽  
V. Bonjean ◽  
N. Malavasi ◽  
M. Douspis
Keyword(s):  
Physical Properties ◽  
Large Scale ◽  
Sloan Digital Sky Survey ◽  
Gas Temperature ◽  
Matter Distribution ◽  
Microwave Background ◽  
Galaxy Groups ◽  
Sky Survey ◽  
Dark Matter Distribution ◽  
First Time

We studied physical properties of matter in 24 544 filaments ranging from 30 to 100 Mpc in length, identified in the Sloan Digital Sky Survey. We stacked the Comptonization y map produced by the Planck Collaboration around the filaments, excluding the resolved galaxy groups and clusters above a mass of ∼3 × 1013 M⊙. We detected the thermal Sunyaev-Zel’dovich signal for the first time at a significance of 4.4σ in filamentary structures on such a large scale. We also stacked the Planck cosmic microwave background lensing convergence map in the same manner and detected the lensing signal at a significance of 8.1σ. To estimate physical properties of the matter, we considered an isothermal cylindrical filament model with a density distribution following a β-model (β = 2/3). Assuming that the gas distribution follows the dark matter distribution, we estimate that the central gas and matter overdensity δ and gas temperature Te are δ = 19.0−12.1+27.3 and Te = 1.4−0.4+0.4 × 106 K, which results in a measured baryon fraction of 0.080−0.051+0.116 × Ωb.

Mapping the Universe: Surveys of the Sky as Discovery Engines in Astronomy

Daedalus ◽  
2014 ◽  
Vol 143 (4) ◽  
pp. 93-102 ◽  
Author(s):  
Michael A. Strauss
Keyword(s):  
Physical Properties ◽  
Sloan Digital Sky Survey ◽  
Electromagnetic Spectrum ◽  
Visible Part ◽  
Sky Survey ◽  
Celestial Sphere ◽  
The Universe

Astronomers can map the sky in many ways: observing in different regions of the electromagnetic spectrum, obtaining spectra of stars and galaxies to determine their physical properties and distances, and repeatedly observing to measure the variability, explosions, and motions of celestial objects. In this review I describe recent surveys of the sky astronomers have carried out, focusing on those in the visible part of the spectrum. I describe in detail the Sloan Digital Sky Survey, an ongoing imaging and spectroscopic survey of over one quarter of the celestial sphere. I also discuss some of the major surveys planned for the next decade, using telescopes both on the ground and in space.

scholarly journals TRIENNIAL REPORT

2015 ◽  
Vol 11 (T29A) ◽  
pp. 340-364
Author(s):  
Steve Chesley ◽  
Daniela Lazzaro ◽  
Andrea Milani ◽  
Yoshikawa Makoto ◽  
Shinsuke Abe ◽  
...  
Keyword(s):  
Solar System ◽  
Size Distribution ◽  
Space Mission ◽  
Minor Planet ◽  
Sky Survey ◽  
Solar System Bodies ◽  
Band Survey

This triennium has seen progress in a number of directions related to Commission 20 objectives. Foremost, the growth in the number of astrometric observations of small solar system bodies continues to accelerate and the total number of measurements recorded by the Minor Planet Center now exceeds 135 million. Currently the Pan-STARRS project and the Catalina Sky Survey (CSS) dominate detection and discovery efforts, while the NEO-WISE space mission contributes infrared detections valuable for understanding the size distribution of populations. Looking forward, the Large Synoptic Survey Telescope (LSST) is now funded and in construction on Cerro Pachon in Chile. LSST has the potential to revolutionize the field by conducting a multi-color, ten-year, all-sky survey with a limiting magnitude ~24.5 in the r-band. Survey operations are set to begin in 2022.

Southern Hemisphere Seti Survey: Five Years of Project Meta II

1997 ◽  
Vol 161 ◽  
pp. 611-621
Author(s):  
Guillermo A. Lemarchand ◽  
Fernando R. Colomb ◽  
E. Eduardo Hurrell ◽  
Juan Carlos Olalde
Keyword(s):  
Southern Hemisphere ◽  
Scattering Theory ◽  
Galactic Plane ◽  
Narrow Band ◽  
Neutral Hydrogen ◽  
Sky Survey ◽  
Inertial Frames ◽  
Interstellar Scattering ◽  
Extraterrestrial Origin ◽  
Spectral Channels

AbstractProject META II, a full sky survey for artificial narrow-band signals, has been conducted from one of the two 30-m radiotelescopes of the Instituto Argentino de Radioastronomía (IAR). The search was performed near the 1420 Mhz line of neutral hydrogen, using a 8.4 million channels Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earths rotation, which provides a characteristic changing signature for narrow-band signals of extraterrestrial origin. Among the 2 × 1013spectral channels analyzed, 29 extra-statistical narrow-band events were found, exceeding the average threshold of 1.7 × 10−23Wm−2. The strongest signals that survive culling for terrestrial interference lie in or near the galactic plane. A description of the project META II observing scheme and results is made as well as the possible interpretation of the results using the Cordes-Lazio-Sagan model based in interstellar scattering theory.

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