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Related papers: Quasometry, Its Use and Purpose

200 papers

We use simple comparisons of the optical and radio properties of the wide separation (3'' to 10'') quasar pairs to demonstrate that they are binary quasars rather than gravitational lenses. The most likely model is that all the pairs are…

Astrophysics · Physics 2007-05-23 C. S. Kochanek , E. E. Falco , J. A. Munoz

Interferometry is a powerful technique for making sensitive, high-fidelity images of the sky, but is limited in its ability to measure extended or diffuse emission. Better images of extended astronomical objects can be obtained by…

Instrumentation and Methods for Astrophysics · Physics 2020-06-12 Brian S. Mason

In normal observation procedures, the position of the observer is specified by GPS and celestial positions of an object will be calculated. But in some situations, like small zenith angle FOVs, GPS doesn't work. Therefore in this study, the…

Instrumentation and Methods for Astrophysics · Physics 2018-06-05 Meysam Izadmehr , Mehdi Khakian Ghom

CubeSats are small satellites built in standard sizes and form factors, which have been growing in popularity but have thus far been largely ignored within the field of astronomy. When deployed as space-based telescopes, they enable science…

Instrumentation and Methods for Astrophysics · Physics 2018-09-05 Evgenya L. Shkolnik

Astrometry -- the precise measurement of positions and motions of celestial objects -- has emerged as a promising avenue for characterizing the dark matter population in our Galaxy. By leveraging recent advances in simulation-based…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-06 Siddharth Mishra-Sharma

Galaxy redshift surveys can be used to detect gravitationally-lensed quasars if the spectra obtained are searched for the quasars' emission lines. Previous investigations of this possibility have used simple models to show that the 2 degree…

Astrophysics · Physics 2008-11-26 Daniel J. Mortlock , Rachel L. Webster

A cosmic ray observatory with full-sky coverage can exploit standard anisotropy analysis methods that do not work if part of the celestial sphere is never seen. In particular, the distribution of arrival directions can be fully…

Astrophysics · Physics 2009-10-31 Paul Sommers

Quantum entanglement has the potential to revolutionize the entire field of interferometric sensing by providing many orders of magnitude improvement in interferometer sensitivity. The quantum-entangled particle interferometer approach is…

Quantum Physics · Physics 2007-05-23 Kishore T. Kapale , Leo D. Didomenico , Hwang Lee , Pieter Kok , Jonathan P. Dowling

We apply instance-based machine learning in the form of a k-nearest neighbor algorithm to the task of estimating photometric redshifts for 55,746 objects spectroscopically classified as quasars in the Fifth Data Release of the Sloan Digital…

Astrometry is a powerful technique to study the populations of extrasolar planets around nearby stars. It gives access to a unique parameter space and is therefore required for obtaining a comprehensive picture of the properties,…

Solar and Stellar Astrophysics · Physics 2015-06-17 J. Sahlmann , P. F. Lazorenko , A. Mérand , D. Queloz , D. Ségransan , J. Woillez

Astronomical polarimetry is a powerful technique that can provide physical information sometimes difficult or impossible to obtain by any other type of observation. Almost every class of binary star can benefit from polarimetric…

Astrophysics · Physics 2007-05-23 N. Manset

Quasars are the most luminous sources in the Universe. They are currently observed out to redshift z ~ 7 when the Universe was less than one tenth of its present age. Since their discovery 50 years ago astronomers have dreamed of using them…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Paola Marziani , Jack W. Sulentic

The extreme conditions found near black holes and neutron stars provide a unique opportunity for testing physical theories. Observations of both types of compact objects can be used to probe regions of strong gravity, allowing for tests of…

High Energy Astrophysical Phenomena · Physics 2009-02-25 John A. Tomsick , Andreas Quirrenbach , Shrinivas R. Kulkarni , Stuart B. Shaklan , Xiaopei Pan

Viewing high-redshift sources at near-opposite directions on the sky can assure, by light-travel-time arguments, acausality between their emitted photons. One utility would be true random-number generation, by sensing these via two…

Instrumentation and Methods for Astrophysics · Physics 2025-04-15 Eric Steinbring

The Breakthrough Starshot project aims to send centimeter-sized, gram-scale "StarChip" probes to Alpha Centauri at a speed of $\sim0.2c$. On the other hand, Zhang \& Li recently proposed that trans-relativistic cameras may be sent to any…

High Energy Astrophysical Phenomena · Physics 2019-05-28 Jin-Ping Zhu , Bing Zhang , Yuan-Pei Yang

Testing the distance-sum-rule in strong lensing systems provides an interesting method to determine the curvature parameter $\Omega_k$ using more local objects. In this paper, we apply this method to a quite recent data set of strong…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-06 Jing-Zhao Qi , Shuo Cao , Sixuan Zhang , Marek Biesiada , Yan Wu , Zong-Hong Zhu

The astrometry technique is an important tool for detecting and characterizing exoplanets of different type. In this review, the different projects which are either operating, in construction or in discussion are presented and their…

Earth and Planetary Astrophysics · Physics 2009-12-03 F. Malbet , A. Sozzetti , P. Lazorenko , R. Launhardt , D. Segransan , F. Delplancke , N. Elias , M. Muterspaugh , A. Quirrenbach , S. Reffert , G. van Belle

The history of astrometry, the branch of astronomy dealing with the positions of celestial objects, is a lengthy and complex chronicle, having its origins in the earliest records of astronomical observations more than two thousand years…

History and Philosophy of Physics · Physics 2015-06-11 Michael Perryman

The Closeby Habitable Exoplanet Survey (CHES) aims to achieve microarcsecond-level astrometry of about one hundred nearby FGK-type stars within 10 parsecs to detect Earth-like planets. Such precision exceeds the capability of absolute…

Earth and Planetary Astrophysics · Physics 2026-03-31 Dongjie Tan , Jianghui Ji , Chunhui Bao , Xiumin Huang , Guo Chen , Su Wang , Yao Dong , Jiacheng Liu , Zi Zhu , Haitao Li , Junbo Zhang , Liang Fang , Dong Li , Lei Deng

Astrometry, the measurement of positions and motions of the stars, is one of the oldest disciplines in Astronomy, extending back at least as far as Hipparchus' discovery of the precession of Earth's axes in 190 BCE by comparing his catalog…

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