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Related papers: 1/f Noise Analysis for FAST HI Intensity Mapping D…

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Radio-frequency interference (RFI) is a major systematic limitation in radio astronomy, particularly for science cases requiring high sensitivity, such as 21 cm cosmology. Traditionally, RFI is dealt with by identifying its signature in the…

Upcoming 21-cm intensity surveys will use the hyperfine transition in emission to map out neutral hydrogen in large volumes of the universe. Unfortunately, large spatial scales are completely contaminated with spectrally smooth…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-27 Chirag Modi , Martin White , Anze Slosar , Emanuele Castorina

We develop a new method for spatially mapping a lower limit on the mass fraction of the cold neutral medium by analyzing the amplitude structure of $\hat T_b(k_v)$, the Fourier transform of $T_b(v)$, the spectrum of the brightness…

In this paper, we investigate the relationship between 150MHz luminosity and star formation rate (the SFR-L150 relation) using 150MHz measurements for a near-infrared selected sample of 118,517 $z<1$ galaxies. New radio survey data offer…

We propose a mechanism for 1/f-type noise in hopping insulators based on the multi-electron charge redistribution within the specific aggregates of the localized states located in the vicinity of the critical resistors. We predict that the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 V. I. Kozub , Y. M. Galperin , V. Vinokur

As is common with the collection of astronomical data, signals are frequently dominated by noise. However, when performing FTs of light curves, re-binning data can improve the signal-to-noise ratio (SNR) at lower frequencies. Using data…

Solar and Stellar Astrophysics · Physics 2022-01-04 Thomas Huckans , Peter Stine

We model a 21 cm intensity mapping survey in the redshift range 0.01<z<1.5 designed to simulate the skies as seen by future radio telescopes such as the Square Kilometre Array (SKA), including instrumental noise and Galactic foregrounds. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-27 L. Wolz , F. B. Abdalla , C. Blake , J. R. Shaw , E. Chapman , S. Rawlings

Power system frequency could be captured by digital recordings and extracted to compare with a reference database for forensic time-stamp verification. It is known as the electric network frequency (ENF) criterion, enabled by the properties…

Cryptography and Security · Computer Science 2020-11-03 Guang Hua , Qingyi Wang , Dengpan Ye , Haijian Zhang

This paper presents an ultra-low noise L-band radio astronomical cryogenic receiver for FAST telescope. The development of key low noise microwave parts of Coupling-LNA and conical quad-ridge OMT and reasonable system integration achieve…

Instrumentation and Methods for Astrophysics · Physics 2021-09-08 Hong-Fei Liu , Chuan He , Jin Wang , Peng Jiang , Sheng-Wang Wang , Yang Wu , Hang Zhang , Jin-You Song , Xiang-Wei Shi , Ming-Lei Guo

We develop a system for measurements of power spectra of transmitted light intensity fluctuations, in which the extraneous noise, including shot noise, is reduced. In essence, we just apply light, measure the power of the transmitted light…

Atomic Physics · Physics 2023-07-19 Takahisa Mitsui , Kenichiro Aoki

Radio Frequency Interference (RFI) poses a significant challenge in radio astronomy, arising from terrestrial and celestial sources, disrupting observations conducted by radio telescopes. Addressing RFI involves intricate heuristic…

Neural and Evolutionary Computing · Computer Science 2024-12-09 Nicholas J. Pritchard , Andreas Wicenec , Mohammed Bennamoun , Richard Dodson

Modern resonant sensing tools can achieve increasingly high quality factors, which correspond to extremely narrow linewidths. In such systems, time-variation of the resonator's natural frequency can potentially impact its ability to…

Instrumentation and Detectors · Physics 2026-03-24 Hao-Ran Cui , Saarik Kalia , Zhen Liu

The presence and nature of low-frequency (0.1-10~mHz) Alfv\'enic waves in the corona has been established over the last decade, with many of these results coming from coronagraphic observations of the infrared Fe XIII line. The Cryo-NIRSP…

Solar and Stellar Astrophysics · Physics 2025-02-21 Richard J. Morton , Momchil Molnar , Steven R. Cranmer , Thomas A. Schad

We present an extragalactic HI 21-cm absorption lines catalog from a blind search at z $\leqslant$ 0.35, using drift-scan data collected in 1325.6 hours by the ongoing Commensal Radio Astronomy FasT Survey (CRAFTS) and FAST All Sky HI…

We report new experimental hyperfine structure (HFS) constants of neutral and singly ionized scandium (Sc I and Sc II). We observed spectra of Sc-Ar and Sc-Ne hollow cathode discharges in the region 200-2500 nm (50,000-4000 cm$^{-1}$) using…

Atomic Physics · Physics 2022-09-26 Hala , G. Nave

We numerically investigate the noise scaling in high-Tc commensurate 1D and 2D SQUID arrays. We show that the voltage noise spectral density in 1D arrays violates the scaling rule of ~1/Np for the number Np of Josephson junctions in…

Superconductivity · Physics 2024-10-01 Oscar A. Nieves , Karl-H Müller

Observations of redshifted 21cm radiation from HI at high redshifts is an important future probe of reionization. We consider the Multi-frequency Angular Power Spectrum (MAPS) to quantify the statistics of the HI signal as a joint function…

Astrophysics · Physics 2008-11-26 Kanan K. Datta , T. Roy Choudhury , Somnath Bharadwaj

Aims: We have analyzed low frequency radio data of tidal disruption event (TDE) Swift J1644+57 to search for a counterpart. We consider how brief transient signals (on the order of seconds or minutes) originating from this location would…

We investigate the generation of quantum operations for one-qubit systems under classical noise with 1/f^\alpha power spectrum, where 2>\alpha > 0. We present an efficient way to approximate the noise with a discrete multi-state Markovian…

We report that low frequency (up to 200 kHz) noise spectra of magnetic tunnel junctions with areas ~10^{-10}cm^2$ at 10 Kelvin deviate significantly from the typical 1/f behavior found in large area junctions at room temperature. In most…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 B. Zhong , Y. Chen , S. Garzon , T. M. Crawford , R. A. Webb