Summary Talk: Multi-Wavelength Sky Surveys

1997 ◽  
pp. 493-499
Author(s):  
O. Lahav
Keyword(s):  
Sky Surveys ◽  
Multi Wavelength ◽  
Summary Talk

scholarly journals Summary Talk : Multi-Wavelength Sky Surveys

1998 ◽  
Vol 179 ◽  
pp. 493-499
Author(s):  
O. Lahav
Keyword(s):  
Gamma Rays ◽  
Dimensional Space ◽  
Instrument Design ◽  
List Type ◽  
Type Number ◽  
Sky Surveys ◽  
3 Dimensional ◽  
Multi Wavelength ◽  
The Universe ◽  
Summary Talk

An astronomer's career can be viewed in a 3-dimensional space where the (nearly orthogonal) axes are : – the objects of interest (from planets to the Universe),– techniques (from instrument design to analytic calculations),– the wavelength (from the radio to gamma rays).

scholarly journals An Updated Multi-Wavelength Radio and Optical Catalog of Quasars and Radio Galaxies

2013 ◽  
Vol 9 (S304) ◽  
pp. 238-239 ◽  
Author(s):  
Amy E. Kimball ◽  
Željko Ivezić
Keyword(s):  
Spectral Index ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Large Area ◽  
Sky Surveys ◽  
The North ◽  
Multi Wavelength ◽  
Optical Surveys ◽  
Quasars And Radio Galaxies ◽  
North Galactic

AbstractWe present a catalog of millions of radio sources, created by consolidating large-area radio and optical surveys GB6 (6cm), FIRST (20cm), NVSS (20cm), WENSS (92cm), VLSS (4m), and SDSS DR9 (optical). The region where all surveys overlap covers 3269 deg2 in the North Galactic Cap, and contains >160,000 20-cm sources, with about 12,000 detected in all five radio surveys and over one-third detected optically. Combining parameters from the sky surveys allows easy and efficient classification by radio and optical morphology and radio spectral index. The catalog is available at http://www.atnf.csiro.au/people/Amy.Kimball/radiocat.shtml.

scholarly journals Exposing New Components of the X-Ray Background with Multi-Wavelength Sky Surveys

1998 ◽  
Vol 179 ◽  
pp. 358-359
Author(s):  
E.C. Moran
Keyword(s):  
Selection Criterion ◽  
Infrared Detection ◽  
Large Area ◽  
Sky Surveys ◽  
X Ray ◽  
Multi Wavelength ◽  
X Ray Background ◽  
Area X ◽  
Einstein Observatory

The evolving class of objects responsible for the majority of the cosmic X-ray background (XRB) remains at large nearly three and a half decades after the discovery of the XRB. Surveys of sources selected on the basis of their X-ray properties alone provide an unbiased picture of the X-ray sky, but to date they have not been ideal for the discovery of rare types of X-ray sources at faint fluxes: large-area X-ray surveys have been restricted to bright sources, while deep X-ray surveys have been limited to very small patches of sky. X-ray selection coupled with another selection criterion, e.g., a radio or infrared detection, complements “pure” X-ray surveys by (1) permitting the exploration of large areas of sky to faint flux limits for types of extragalactic X-ray sources not well represented in other surveys, and (2) assisting the location of the optical counterparts of these X-ray sources. Using this approach, I have searched for new components of the XRB among the faintest X-ray sources detected by the Einstein Observatory.

scholarly journals Evolution of the NASA/IPAC Extragalactic Database (NED) into a Data Mining Discovery Engine. II. Current Contents and Future Plans

2018 ◽  
Vol 186 ◽  
pp. 03001 ◽  
Author(s):  
Marion Schmitz
Keyword(s):  
Data Mining ◽  
User Interface ◽  
Data Integration ◽  
Journal Articles ◽  
Sky Surveys ◽  
Multi Wavelength ◽  
Integration Techniques ◽  
Physical Quantities ◽  
Made In ◽  
Future Plans

Recent advances have been made in evolving the NASA/IPAC Extragalactic Database (NED) into a data mining discovery engine. Infrastructure changes and data integration techniques are enabling more than a 10-fold expansion. NED will soon contain over a billion objects with their fundamental attributes (such as names, positions, redshifts, fluxes, and diameters) determined via cross-identifications among the largest sky surveys and over 100,000 smaller but scientifically important catalogs and journal articles. In addition, enhancements to the user interface, including new APIs, VO protocols, and queries involving derived physical quantities, will provide new pathways for multi-wavelength studies of large extragalactic samples.

scholarly journals The Aladin Interactive Sky Atlas

1998 ◽  
Vol 179 ◽  
pp. 469-470
Author(s):  
F. Bonnarel ◽  
H. Ziaeepour ◽  
J.G. Bartlett ◽  
O. Bienaymé ◽  
M. Crézé ◽  
...  
Keyword(s):  
Software Package ◽  
Object Identification ◽  
Sky Surveys ◽  
Visual Comparison ◽  
Astronomical Object ◽  
Multi Wavelength ◽  
User Data ◽  
The Subject ◽  
Source Extraction

The subject of this symposium, Multi-Wavelength Sky Surveys naturally invokes a discussion of methods of astronomical object identification and classification: Given a set of objects detected at a certain waveband, how does one integrate the new sources with previous data? The ALADIN system (Paillou et al. 1994) of the CDS is a software package designed to tackle this problem: It provides simultaneous access to digitized sky photographs, catalogs and databases to facilitate direct, visual comparison of user data with previously classified data, as well as automatic source extraction and calibration tools.

scholarly journals Towards a Better Understanding of Active Galactic Nuclei

1998 ◽  
Vol 179 ◽  
pp. 257-265
Author(s):  
P. Padovani
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Class I ◽  
Sky Surveys ◽  
Basic Properties ◽  
Open Questions ◽  
Multi Wavelength ◽  
Γ Ray

Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the γ-ray band. After reviewing their basic properties, I will assess how well we know the multifrequency spectra of AGN as a class. I will then briefly illustrate how currently available and forthcoming sky surveys will help in addressing some of the open questions of AGN studies. Finally, an analysis of the problem of the missing Type 2 QSO will exemplify the dangers of monochromatic sky surveys for AGN.

Seti Figure of Merit

1997 ◽  
Vol 161 ◽  
pp. 711-717 ◽  
Author(s):  
John W. Dreher ◽  
D. Kent Cullers
Keyword(s):  
Figure Of Merit ◽  
Qualitative Difference ◽  
Current Generation ◽  
Detection Range ◽  
Sky Surveys ◽  
Independent Observations ◽  
Good For

AbstractWe develop a figure of merit for SETI observations which is anexplicitfunction of the EIRP of the transmitters, which allows us to treat sky surveys and targeted searches on the same footing. For each EIRP, we calculate the product of terms measuring the number of stars within detection range, the range of frequencies searched, and the number of independent observations for each star. For a given set of SETI observations, the result is a graph of merit versus transmitter EIRP. We apply this technique to several completed and ongoing SETI programs. The results provide a quantitative confirmation of the expected qualitative difference between sky surveys and targeted searches: the Project Phoenix targeted search is good for finding transmitters in the 109to 1014W range, while the sky surveys do their best at higher powers. Current generation optical SETI is not yet competitive with microwave SETI.

Observations for the Role of Flux rope Eruption in a Geoeffective Solar Flare

2014 ◽  
Vol 4 (2) ◽  
pp. 555-564
Author(s):  
A.M Aslam
Keyword(s):  
Solar Flare ◽  
Flux Rope ◽  
Magnetic Configuration ◽  
Solar Dynamics Observatory ◽  
Multi Wavelength ◽  
Solar Dynamics ◽  
Halo Coronal Mass Ejection ◽  
Mass Ejection ◽  
The Waves

On September 24, 2011 a solar flare of M 7.1 class was released from the Sun. The flare was observed by most of the space and ground based observatories in various wavebands. We have carried out a study of this flare to understand its causes on Sun and impact on earth. The flare was released from NOAA active region AR 11302 at 12:33 UT. Although the region had already produced many M class flares and one X- class flare before this flare, the magnetic configuration was not relaxed and still continued to evolve as seen from HMI observations. From the Solar Dynamics Observatory (SDO) multi-wavelength (131 Ã…, 171 Ã…, 304 Ã… and 1600Ã…) observations we identified that a rapidly rising flux rope triggered the flare although HMI observations revealed that magnetic configuration did not undergo a much pronounced change. The flare was associated with a halo Coronal Mass Ejection (CME) as recorded by LASCO/SOHO Observations. The flare associated CME was effective in causing an intense geomagnetic storm with minimum Dst index -103 nT. A radio burst of type II was also recorded by the WAVES/WIND. In the present study attempt is made to study the nature of coupling between solar transients and geospace.

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