Related Experiment Video
Updated: Jul 21, 2025
07:42
Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator
Published on: December 15, 2021
3.1K
Subsecond periodic radio oscillations in a microquasar.
Pengfu Tian1,2, Ping Zhang1,2, Wei Wang3,4
1Department of Astronomy, School of Physics and Technology, Wuhan University, Wuhan, People's Republic of China.
Nature
|July 26, 2023
Summary
Astronomers detected new 5-Hz periodic oscillations in the microquasar GRS 1915+105, revealing transient features in its relativistic jet. These findings offer insights into the dynamics of accreting black hole systems.
Area of Science:
- Astrophysics
- High-energy astrophysics
- Black hole physics
Background:
- Accreting black holes, such as microquasars, commonly exhibit powerful relativistic jets.
- GRS 1915+105 is a known black-hole X-ray binary with a relativistic jet, displaying persistent X-ray activity and various quasiperiodic oscillations.
Purpose of the Study:
- To report the detection of transient periodic oscillation features in the radio emission of the microquasar GRS 1915+105.
- To investigate the nature and origin of these newly observed oscillations and their relationship to the relativistic jet.
Main Methods:
- Analysis of radio observations from January 2021 and June 2022 in the 1.05- to 1.45-GHz band.
- Detection and characterization of transient periodic oscillation features.
- Observation of circular polarization during the oscillation phases.
Main Results:
- Two instances of approximately 5-Hz transient periodic oscillation features were detected in the radio band.
- These oscillations occurred in January 2021 and June 2022.
- Circular polarization was observed concurrently with these oscillations.
Conclusions:
- The detected 5-Hz oscillations provide new observational constraints on the physical processes occurring near the black hole and within the relativistic jet.
- The presence of circular polarization may offer clues about the magnetic field geometry and particle acceleration mechanisms in the jet.
- Further studies are needed to fully understand the origin and implications of these transient phenomena in GRS 1915+105.
Related Concept Videos
01:11Atomic Nuclei: Larmor Precession Frequency
1.5K
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,...
1.5K
01:30Oscillations In An LC Circuit
2.3K
An idealized LC circuit of zero resistance can oscillate without any source of emf by shifting the energy stored in the circuit between the electric and magnetic fields. In such an LC circuit, if the capacitor contains a charge q before the switch is closed, then all the energy of the circuit is initially stored in the electric field of the capacitor. This energy is given by
2.3K
02:18The Bohr Model
55.7K
Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded by lighter and even tinier electrons continually moving about the nucleus was well established. This picture was called the planetary model since it pictured the atom as a miniature “solar system” with the electrons orbiting the nucleus like planets orbiting the sun. The simplest atom is hydrogen, consisting of a single proton as...
55.7K
01:10Generating Electromagnetic Radiations
3.1K
The German physicist Heinrich Hertz (1857–1894) was the first to generate and detect certain types of electromagnetic waves in the laboratory. Starting in 1887, he performed a series of experiments that confirmed the existence of electromagnetic waves and verified that they travel at the speed of light. Hertz used an alternating-current RLC (resistor-inductor-capacitor) circuit that resonated at a known frequency and connected it to a loop of wire. High voltages induced across the gap in...
3.1K
01:17NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
843
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.
843
01:29Plane Electromagnetic Waves II
3.1K
Consider a plane wavefront traveling in position x-direction with a constant speed. This wavefront can be utilized to obtain the relationship between electric and magnetic fields with the help of Faraday's law.
3.1K