English
Related papers

Related papers: Human Contrast Threshold and Astronomical Visibili…

200 papers

We examined variations in the 160/250 and 250/350 micron surface brightness ratios within 24 nearby (<30 Mpc) face-on spiral galaxies observed with the Herschel Space Observatory to identify the heating mechanisms for dust emitting at these…

We have obtained OH spectra of four transitions in the $^2\Pi_{3/2}$ ground state, at 1612, 1665, 1667, and 1720 MHz, toward 51 sightlines that were observed in the Herschel project Galactic Observations of Terahertz C+. The observations…

It is well-known that no local model - in theory - can simulate the outcome statistics of a Bell-type experiment as long as the detection efficiency is higher than a threshold value. For the Clauser-Horne-Shimony-Holt (CHSH) Bell inequality…

Quantum Physics · Physics 2023-02-14 Shihan Sajeed , Nigar Sultana , Charles Ci Wen Lim , Vadim Makarov

According to astrophysical observations value of recession velocity in a certain point is proportional to a distance to this point. The proportionality coefficient is the Hubble constant measured with 5% accuracy. It is used in many…

General Physics · Physics 2017-06-16 Zeinulla Zhanabaev , Serik Khokhlov , Aldiyar Agishev

Standard luminosity ($L$) of 406 main-sequence stars with the most accurate astrophysical parameters are predicted from their absolute magnitudes and bolometric corrections at Johnson $B,V$, and Gaia EDR3 $G$, $G_{BP}$, $G_{RP}$ filters.…

Solar and Stellar Astrophysics · Physics 2022-12-21 Volkan Bakış , Zeki Eker

Gravitational-wave (GW) events can serve as standard sirens for cosmology, as the luminosity distance to source can be directly measured from the waveform amplitude. Specifically, the ``dark'' siren method involves inferring cosmological…

General Relativity and Quantum Cosmology · Physics 2024-08-21 Yijun Wang , Yanbei Chen

The brightness theorem---brightness is nonincreasing in passive systems---is a foundational conservation law, with applications ranging from photovoltaics to displays, yet it is restricted to the field of ray optics. For general linear wave…

Optics · Physics 2019-10-24 Hanwen Zhang , Chia Wei Hsu , Owen D. Miller

With more than 150 blank sky observations at high Galactic latitude, we make a systematic study to the background of the Low Energy Telescope (LE) of the Hard X-ray Modulation Telescope (dubbed as Insight-HXMT). Both the on-ground…

This paper is based on the opening lecture given at the 2017 edition of the Evry Schatzman school on high-angular resolution imaging of stars and their direct environment. Two relevant observing techniques: long baseline interferometry and…

Instrumentation and Methods for Astrophysics · Physics 2019-04-04 Frantz Martinache

We continue to build support for the proposal to use HII galaxies (HIIGx) and giant extragalactic HII regions (GEHR) as standard candles to construct the Hubble diagram at redshifts beyond the current reach of Type Ia supernovae. Using a…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Jun-Jie Wei , Xue-Feng Wu , Fulvio Melia

The recent theory of 't Hooft [ Nucl. Phys. Suppl. {\bf 68}, 174 (1998)] models the black hole as a system endowed with an envelope of matter that obeys an equation of state in the form $ p=(\gamma -1)\rho$, and acts as a source in…

General Relativity and Quantum Cosmology · Physics 2009-01-14 I. Brevik

Doing quantitative computed tomography (CT) using Bremsstrahlung sources requires an estimate of the spectrum emitted by the X-ray source. One method of beam hardening correction (BHC), as described by Lifton[1], first uses transmission…

Medical Physics · Physics 2025-08-13 Nikhil Deshmukh

We consider the relative configurational entropy per cell S_Delta as a measure of the degree of spatial disorder for systems of finite-sized objects. It is highly sensitive to deviations from the most spatially ordered reference…

Statistical Mechanics · Physics 2009-10-31 Ryszard Piasecki

Phase difference is central to classical coherence theory. With the advancement of various light-field modulation techniques, artificially generated pseudo-thermal light sources or random light beams can exhibit exotic wavefront correlation…

Optics · Physics 2026-05-25 Yi Cui , Wanting Hou , Jun Xiong , Zhiyuan Ye

We have analized a sample of 327 clusters of galaxies spanning the range 0.06-0.70 in redshift. Strong constraints on their mean intracluster emission by dust have been obtained using maps and catalogs from the HERSCHEL HerMES project;…

Astrophysics of Galaxies · Physics 2017-01-25 C. M. Gutierrez , M. Lopez-Corredoira

The diffuse, unresolved sky provides most of the photons that the Hubble Space Telescope (HST) receives, yet remains poorly understood. HST Archival Legacy program SKYSURF aims to measure the 0.2-1.6 $\mu$m sky surface brightness (sky-SB)…

For over a century physicists have sought a mathematical theory that unites the dual, wave and corpuscle, behaviors that light exhibits. In the early twentieth century H. Bateman was studying a solution that uses wave functions with…

General Physics · Physics 2008-06-09 H. C. Potter

In this paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-31 Wei Zheng , Hong Li , Jun-Qing Xia , You-Ping Wan , Si-Yu Li , Mingzhe Li

The next generation of telescopes will usher in an era of precision cosmology, capable of determining the cosmological model to beyond the percent level. For this to be effective, the theoretical model must be understood to at least the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Obinna Umeh , Chris Clarkson , Roy Maartens

A cross-correlation technique of lensing tomography is presented to measure the evolution of dark energy in the universe. The variation of the weak lensing shear with redshift around massive foreground objects like bright galaxies and…

Astrophysics · Physics 2008-11-26 Bhuvnesh Jain , Andy Taylor