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We describe the data processing pipeline developed to reduce the pointing observation data of Lunar-based Ultraviolet Telescope (LUT), which belongs to the Chang'e-3 mission of the Chinese Lunar Exploration Program. The pointing observation…

Instrumentation and Methods for Astrophysics · Physics 2015-08-19 Xian-Min Meng , Li Cao , Yu-Lei Qiu , Chao Wu , Jing Wang , Xu-Hui Han , Jin-Song Deng , Li-Ping Xin , Hong-Bo Cai , Jian-Yan Wei

We report a frequency measurement of the 1S0-3P0 transition of 87Sr atoms in an optical lattice clock. The frequency is determined to be 429 228 004 229 879 (5) Hz with a fractional uncertainty that is comparable to state-of-the-art optical…

Ultra-precise optical clocks in space will allow new studies in fundamental physics and astronomy. Within an European Space Agency (ESA) program, the Space Optical Clocks (SOC) project aims to install and to operate an optical lattice clock…

Precise beam based measurement and correction of magnetic optics is essential for the successful operation of accelerators. The LOCO algorithm is a proven and reliable tool, which in some situations can be improved by using a broader class…

The Kepler space telescope leaves a legacy of tens of thousands of stellar rotation period measurements. While many of these stars show strong periodicity, there exists an even bigger fraction of stars with irregular variability for which…

Solar and Stellar Astrophysics · Physics 2023-10-04 Timo Reinhold , Alexander I. Shapiro , Sami K. Solanki , Gibor Basri

Optical lattice clocks (OLCs) are at the forefront of precision metrology, operating near a standard quantum limit (SQL) set by quantum noise. Harnessing quantum entanglement offers a promising route to surpass this limit, yet there remain…

We present new constraints on ultralight axion-like particles (ALPs) through multi-epoch measurements of differential birefringence induced due to a coupling ($g_{a\gamma}$) between the ALP and electromagnetic fields. Broadband polarimetric…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 Shivani Deshmukh , Aritra Basu , Dominik J. Schwarz , Yuko Urakawa , Sui Ann Mao

Pulsar timing is a process of iteratively fitting pulse arrival times to constrain the spindown, astrometric, and possibly binary parameters of a pulsar, by enforcing integer numbers of pulsar rotations between the arrival times. Phase…

Instrumentation and Methods for Astrophysics · Physics 2021-12-13 Camryn Phillips , Scott Ransom

Global Positioning System (GPS) dissemination of frequency standards is ubiquitous at present, providing the most widespread time and frequency reference for the majority of industrial and research applications worldwide. On the other hand,…

The spin-down law of pulsars is generally perturbed by two types of timing irregularities: glitches and timing noise. Glitches are sudden changes in the rotational frequency of pulsars, while timing noise is a discernible stochastic…

The timing (cross-)calibration of astronomical instruments is often done by comparing pulsar times-of-arrival (TOAs) to a reference timing model. In high-energy astronomy, the choice of solar system ephemerides and source positions used to…

Comparisons of high-accuracy optical atomic clocks \cite{Ludlow2015} are essential for precision tests of fundamental physics \cite{Safronova2018}, relativistic geodesy \cite{McGrew2018, Grotti2018, Delva2019}, and the anticipated…

Timing observations from the Nanshan 26-m radio telescope for nine pulsars between 2000 and 2014 have been used to search for glitches. The data span for nine pulsars ranges from 11.6 to 14.2 years. From the total of 114 yr of pulsar…

High Energy Physics - Phenomenology · Physics 2022-08-17 Zu-Rong Zhou , Jing-Bo Wang , Na Wang , Jian-Ping Yuan , Fei-Fei Kou , Shi-Jun Dang

We experimentally demonstrate the collective emission behavior and suppressed cavity-pulling effect of four-level active optical clock with Cesium atoms. Thermal Cesium atoms in a glass cell velocity selective pumped with a 455.5 nm laser…

Atomic Physics · Physics 2014-04-25 Zhichao Xu , Wei Zhuang , Jingbiao Chen

Radio telescope arrays are interferometers and thus require coherent capture and processing of the signal from the astronomical source being observed. In ALMA this is accomplished by using a clock at each antenna for down-conversion and…

Instrumentation and Methods for Astrophysics · Physics 2021-07-12 Brent Carlson

To better understand the influence of the activity cycle on the solar atmosphere, we report the time variation of the radius observed at 37 GHz ($\lambda$=8.1 mm) obtained by the Mets\"ahovi Radio Observatory (MRO) through Solar Cycles 22…

Solar and Stellar Astrophysics · Physics 2019-12-17 Caius L. Selhorst , Juha Kallunki , C. G. Giménez de Castro , Adriana Valio , Joaquim E. R. Costa

We characterize the problem of artificial polarization for the Submillimeter High Angular Resolution Polarimeter (SHARP) through the use of simulated data and observations made at the Caltech Submillimeter Observatory (CSO). These…

Astrophysics · Physics 2009-11-13 Michael Attard , Martin Houde , Giles Novak , John E. Vaillancourt

Optical atomic clocks have demonstrated revolutionary advances in precision timekeeping, but their applicability to the real world is critically dependent on whether such clocks can operate outside a laboratory setting. The challenge to…

Lunar laser ranging (LLR) currently delivers mm-class tests of relativistic gravity and the lunar interior, but further gains are limited by photon-starved pulsed systems, array-induced pulse broadening, and atmospheric variability. This…

Instrumentation and Methods for Astrophysics · Physics 2026-05-20 Slava G. Turyshev

Questioning the presumably most basic assumptions about the structure of space and time has revolutionized our understanding of Nature. State-of-the-art atomic clocks make it possible to precisely test fundamental symmetry properties of…

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