Results 81 to 90 of about 112,522 (249)

A CATALOG OF QUASAR PROPERTIES FROM SLOAN DIGITAL SKY SURVEY DATA RELEASE 7 [PDF]

, 2010
We present a compilation of properties of the 105,783 quasars in the Sloan Digital Sky Survey Data Release 7 (DR7) quasar catalog. In this product, we compile continuum and emission line measurements around the Hα, Hβ, Mg ii, and C iv regions, as well as
Yue Shen, G. Richards, M. Strauss, P. Hall, D. Schneider, S. Snedden, D. Bizyaev, H. Brewington, V. Malanushenko, E. Malanushenko, D. Oravetz, K. Pan, A. Simmons   +12 more
semanticscholar   +1 more source

Circular Economy Policies and Business Models in the EU Renewable Energy Sector: The Case of Solar Photovoltaic Industry

Business Strategy and the Environment, EarlyView.
ABSTRACT The circular economy is an approach to decouple economic growth from environmental impacts. In Europe, its development is driven by policies that guide market dynamics through regulations and by businesses innovating with new circular models.
Roger Nyffenegger, Brian Baldassarre, Nancy Bocken, Stefan N. Groesser   +3 more
wiley   +1 more source

MEASURING THE TIME DELAYS IN GRAVITATIONALLY LENSED QUASARS IN THE PRESENCE OF MICROLENSING

Radio Physics and Radio Astronomy, 2014
A method to measure the time delays in gravitationally lensed quasars is proposed, which provides a simple and transparent procedure to eliminate the effects of microlensing events.
V. S. Tsvetkova, V. M. Shulga, L. A. Berdina   +2 more
doaj   +1 more source

Think Outside the Color Box: Probabilistic Target Selection and the SDSS-XDQSO Quasar Targeting Catalog

, 2011
We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts (2.5
Abazajian, Abazajian, Abell, Adam D. Myers, Adelman-McCarthy, Adelman-McCarthy, Aihara, Benjamin A. Weaver, Bishop, Bovy, Butler, Chelouche, David J. Schlegel, David W. Hogg, Dempster, Donald P. Schneider, Eisenstein, Erin S. Sheldon, Fan, Gunn, Gunn, Hennawi, Hennawi, Hogg, Hopkins, Ian D. McGreer, Ivezić, Ivezić, Ivezić, Jessica A. Kirkpatrick, Jiang, Jimenez, Jo Bovy, Joseph F. Hennawi, Kozłowski, Lupton, MacLeod, Martin, McGreer, Myers, Myers, Myers, Myers, Ménard, Nicholas P. Ross, Padmanabhan, Palanque-Delabrouille, Pier, Rasmussen, Richards, Richards, Richards, Richards, Richards, Ross, Schlegel, Schlegel, Schmidt, Schneider, Schölkopf, Scranton, Scranton, Shen, Shen, Smith, Stoughton, Worseck, Xue, Yip, York   +69 more
core   +1 more source

Microlensing variability in the gravitationally lensed quasar Q2237+0305 = the Einstein Cross, I. Spectrophotometric monitoring with the VLT [PDF]

, 2008
We present the results of the first long-term (2.2 years) spectroscopic monitoring of a gravitationally lensed quasar, namely the Einstein Cross Q2237+0305.
A. Eigenbrod, Abajas, Agol, Agol, Burud, Burud, Burud, Cardelli, Chartas, Colley, Courbin, D. Sluse, Dietrich, E. Agol, Eigenbrod, Eigenbrod, Eigenbrod, F. Courbin, Falco, Filippenko, G. Meylan, Gómez-Álvarez, Gómez-Álvarez, Hjorth, Huchra, Irwin, Jakobsson, Kaspi, Keeton, Kent, Kochanek, Kochanek, Koptelova, Lewis, Lewis, Lewis, Magain, Metcalf, Mineshige, Murray, Nemiroff, Richards, Rix, Schechter, Schneider, Schneider, Sluse, Udalski, van Dokkum, Vestergaard, Vuissoz, Wambsganss, Wambsganss, Wandel, Wayth, Wills, Wisotzki, Wisotzki, Witt, Wozniak, Wozniak, Yee, Yonehara   +62 more
core   +2 more sources

First In Vivo 23Na Human Imaging at 10.5 T Using a Combined Sodium‐Proton Transceiver Body Array

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To demonstrate the first in vivo human 23Na MRI at 10.5 T using a novel dual‐tuned transceiver body array and to evaluate a self‐gating approach for respiratory motion compensation, focusing on renal imaging. Methods A custom‐built eight‐channel 23Na‐loop 1H‐dipole transceiver array was designed, constructed, and characterized.
Simon Schmidt, Arcan M. Ertürk, Gregory J. Metzger   +2 more
wiley   +1 more source

Modeling the Broad-Band Emission from the Gamma-Ray Emitting Narrow-Line Seyfert-1 Galaxies 1H 0323+342 and B2 0954+25A

Frontiers in Astronomy and Space Sciences, 2017
Prior to the Fermi-LAT era, only two classes of Active Galactic Nuclei (AGN) were thought to harbor relativistic jets that radiate up to gamma-ray energies: blazars and radio galaxies. The detection of variable gamma-ray emission from Narrow Line Seyfert
Maialen Arrieta-Lobo, Catherine Boisson, Andreas Zech   +2 more
doaj   +1 more source

Discovery of Two Spectroscopically Peculiar, Low-Luminosity Quasars at z~4 [PDF]

, 2007
We report the discovery of two low-luminosity quasars at z~4, both of which show prominent N IV] 1486A emission. This line is extremely rare in quasar spectra at any redshift; detecting it in two out of a sample of 23 objects (i.e., ~ 9% of the sample ...
Ashish Mahabal, Daniel Stern, Eilat Glikman, Fan X., Milan Bogosavljević, S. G. Djorgovski   +5 more
core   +2 more sources

The Discovery of a Luminous Broad Absorption Line Quasar at a Redshift of 7.02 [PDF]

Astrophysical Journal, 2018
Despite extensive efforts, to date only two quasars have been found at z > 7, due to a combination of low spatial density and high contamination from more ubiquitous Galactic cool dwarfs in quasar selection. This limits our current knowledge of the super-
Feige Wang, Jinyi Yang, Xiaohui Fan, M. Yue, Xue-bing Wu, J. Schindler, F. Bian, Jiangtao Li, E. Farina, E. Bañados, F. Davies, R. Decarli, R. Green, Linhua Jiang, J. Hennawi, Yun-Hsin Huang, C. Mazzucchelli, I. McGreer, B. Venemans, F. Walter, Y. Beletsky   +20 more
semanticscholar   +1 more source

Cherenkov Telescope Array Observatory: Die Zukunft der Gammaastronomie

Physik in unserer Zeit, EarlyView.
Im Jahr 1989 hat das Wipple‐Observatorium die erste Quelle hochenergetischer Gammastrahlung entdeckt. 2002 waren dann sechs Quellen bekannt, 2024 schon mehr als 300. Und das ist immer noch lediglich die Spitze des Eisbergs in der jungen Geschichte der Gammaastronomie.
Daniela Hadasch, Daniel Mazin
wiley   +1 more source