Video Experimental Relacionado

Updated: Oct 22, 2025

Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator

Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator

Published on: December 15, 2021

Actividad cromática periódica hasta 120 megahertz en una ráfaga de radio rápida

Inés Pastor-Marazuela^1,2, Liam Connor^1,2,3, Joeri van Leeuwen^4,5

¹Anton Pannekoek Institute, University of Amsterdam, Amsterdam, The Netherlands.

|August 26, 2021

Resumen

Las ráfagas rápidas de radio (FRB) emiten a frecuencias más bajas que las detectadas anteriormente, con ventanas de actividad dependientes de la frecuencia. Este hallazgo desafía los modelos existentes y sugiere que las FRB pueden ocurrir en entornos sin absorción de baja frecuencia.

Área de la Ciencia:

La astrofísica
La radioastronomía

Sus antecedentes:

Las ráfagas rápidas de radio (FRB) son transitorios astrofísicos energéticos de corta duración.
Las detecciones anteriores de FRB se limitaron a frecuencias superiores a 300 MHz, dejando inexploradas las emisiones de frecuencia más baja.

Objetivo del estudio:

Para investigar la emisión de baja frecuencia de FRB 20180916B.
Para determinar si las ventanas de actividad FRB son dependientes de la frecuencia (cromáticas).

Principales métodos:

Observaciones simultáneas por radio de FRB 20180916B a través de una amplia gama de longitudes de onda (de 120 MHz a > 1,4 GHz).
Análisis de la ventana de periodicidad y actividad de FRB 20180916B durante un ciclo completo de 16,35 días.

Principales resultados:

FRB 20180916B emite hasta los 120 MHz.
La ventana de actividad de FRB 20180916B es cromática, siendo más estrecha y más temprana en frecuencias más altas.
FRB 20180916B es más activo por debajo de 200 MHz que a 1,4 GHz para fluencias de ráfaga similares.

Conclusiones:

La cromaticidad observada contradice los modelos binarios de interacción del viento.
La emisión de FRB de baja frecuencia puede propagarse a través de entornos locales, lo que indica que algunos FRB residen en entornos "limpios".
Los resultados proporcionan nuevas restricciones a los mecanismos y entornos de emisión de FRB.

Más Videos Relacionados

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

Published on: August 6, 2018

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Published on: February 10, 2020

Videos de Conceptos Relacionados

IR Frequency Region: X–H Stretching

IR Frequency Region: X–H Stretching

In IR spectroscopy, signals produced by the X−H bonds (such as C−H, O−H, or N−H) can be observed in the frequency range of 2700–4000 cm–1. The C−H stretching vibration forms sharp bands in the region 2850–3000 cm–1. The presence of the O−H stretching vibration leads to the forming of an absorption band in the frequency range 3650–3200 cm−1. At the same time, N−H stretching can be confirmed by absorption bands in...

Atomic Nuclei: Larmor Precession Frequency

Atomic Nuclei: Larmor Precession Frequency

The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...

IR Frequency Region: Fingerprint Region

IR Frequency Region: Fingerprint Region

IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the...

The Electromagnetic Spectrum

The Electromagnetic Spectrum

Electromagnetic waves are categorized according to their wavelengths and frequencies, giving the electromagnetic spectrum. These waves are classified as radio, infrared, ultraviolet, etc. Radio waves refer to electromagnetic radiation with wavelengths ranging from millimeters to kilometers. Radio waves are commonly used for audio communications (i.e., radios) and typically result from an alternating current in the wires of a broadcast antenna. They cover a broad wavelength range and are used...

Intensity Of Electromagnetic Waves

Intensity Of Electromagnetic Waves

The energy transport per unit area per unit time, or the Poynting vector, gives the energy flux of an electromagnetic wave at any specific time. For a plane electromagnetic wave with E0 and B0 as the peak electric and magnetic fields and traveling along the x-axis, the time-varying energy flux can be given by the following equation:

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.