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Related papers: Quasometry, Its Use and Purpose

200 papers

The idea of using stellar photometry for atmospheric monitoring for optical experiments in high-energy astrophysics is seemingly straightforward, but reaching high precision of the order of 0.01 in the determination of the vertical aerosol…

In this whitepaper, we outline how recent technological advances and ongoing developments open qualitatively new science opportunities in cosmology, fundamental physics, and quantum astrophysics. First, intensity interferometry can…

Context: With no conclusive detection to date, the search for exomoons, satellites of planets orbiting other stars, remains a formidable challenge. Detecting these objects, compiling a population-level sample and constraining their…

Since the very beginning of astronomy the location of objects on the sky has been a fundamental observational quantity that has been taken for granted. While precise two dimensional positional information is easy to obtain for observations…

We consider the standard problem of observational astronomy, i.e. the observations of light emission from a distant region of spacetime in general relativity. The goal is to describe the changes between the measurements of the light…

General Relativity and Quantum Cosmology · Physics 2019-04-02 Michele Grasso , Mikołaj Korzyński , Julius Serbenta

We present a method for the photometric selection of candidate quasars in multiband surveys. The method makes use of a priori knowledge derived from a subsample of spectroscopic confirmed QSOs to map the parameter space. The disentanglement…

Astrophysics · Physics 2015-05-13 R. D'Abrusco , G. Longo , N. A. Walton

MASER (Measurements, Analysis, and Simulation of Emission in the Radio range) is a comprehensive infrastructure dedicated to time-dependent low frequency radio astronomy (up to about 50 MHz). The main radio sources observed in this spectral…

Photometric observations of 235 extragalactic objects that are potential targets for the Space Interferometry Mission (SIM) are presented. Mean B, V, R, I magnitudes at the 5% level are obtained at 1 - 4 epochs between 2005 and 2007 using…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Roopesh Ojha , Norbert Zacharias , Gregory S. Hennessey , Ralph A. Gaume , Kenneth J. Johnston

We propose a proper method to measure the size of the narrow line region (NLR) in distant quasars. The apparent angular size of the NLR is, in general, too small to resolve technically. However, it is possible to map the NLR if with…

Astrophysics · Physics 2009-11-11 Atsunori Yonehara

The answers to fundamental science questions in astrophysics, ranging from the history of the expansion of the universe to the sizes of nearby stars, hinge on our ability to make precise measurements of diverse astronomical objects. As our…

Quantum state tomography is a technique in quantum information science used to reconstruct the density matrix of an unknown quantum state, providing complete information about the quantum state. It is of significant importance in fields…

Quantum Physics · Physics 2025-07-23 Wenlong Zhao , Da Zhang , Huili Zhang , Haifeng Yu , Zhang-qi Yin

We present our search program for substellar companions using high-precision relative astronomy. Due to its orbital motion around the star, an unseen substellar companion would produce a periodic "wobble" of the host star, which is the…

Astrophysics · Physics 2012-04-24 T. Roell , A. Seifahrt , R. Neuhäuser

Context. Quasars are spatially stationary, and they are essential objects in astrometry when defining reference frames. However, the census of quasars is far from complete. Mid-infared colors can be used to find quasar candidates because…

Observations of quasar pairs represent a powerful tool in the study of the intergalactic medium, providing in particular information on the quasar radiative feedback not only along the line of sight, but also in the transverse direction. In…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Guido Cupani , Valentina D'Odorico , Stefano Cristiani , Matteo Viel , Eros Vanzella

Detecting any evolution of dimensionless in the ratios of physical quantities, such as the fine structure constant, would prove that the Weak Equivalence Principle is violated and lead to a paradigm shift in physics. High resolution…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-03 Dinko Milaković

Astrometry plays a crucial role in understanding the structure, dynamics, and evolution of celestial objects by providing precise measurements of their positions and motions. We propose a new approach to wide-field, relative astrometry,…

Instrumentation and Methods for Astrophysics · Physics 2025-04-25 Ryou Ohsawa , Daisuke Kawata , Takafumi Kamizuka , Yoshiyuki Yamada , Wolfgang Löffler , Michael Biermann

We use 118 H$\beta$ quasar (QSO) observations in the redshift range $0.0023 \leq z \leq 0.89$ to simultaneously constrain cosmological model parameters and QSO 2-parameter radius-luminosity ($R-L$) relation parameters in six different…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-16 Narayan Khadka , Mary Loli Martínez-Aldama , Michal Zajaček , Bożena Czerny , Bharat Ratra

High-precision astrometry at the sub-microarcsecond level opens up a window to study Earth-like planets in the habitable zones of Sun-like stars, and to determine their masses. It thus promises to play an important role in exoplanet science…

Earth and Planetary Astrophysics · Physics 2018-12-05 Markus Janson , Alexis Brandeker , Celine Boehm , Alberto Krone Martins

Selection of extragalactic point sources, e.g. QSOs, is often hampered by significant selection effects causing existing samples to have rather complex selection functions. We explore whether a purely astrometric selection of extragalactic…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Kasper E. Heintz , Johan P. U. Fynbo , Erik Høg