author={Fereshteh Rajabi and Martin Houde},
  journal={The Astrophysical Journal},
We have applied the concept of superradiance introduced by Dicke in 1954 to astrophysics by extending the corresponding analysis to the magnetic dipole interaction characterizing the atomic hydrogen 21 cm line. Although it is unlikely that superradiance could take place in thermally relaxed regions and that the lack of observational evidence of masers for this transition reduces the probability of detecting superradiance, in situations where the conditions necessary for superradiance are met… 

Dicke’s Superradiance in Astrophysics

It is generally assumed that in the interstellar medium much of the emission emanating from atomic and molecular transitions within a radiating gas happen independently for each atom or molecule, but

Dicke's Superradiance in Astrophysics. II -- The OH 1612 MHz Line

We apply the concept of superradiance that was introduced by Dicke in 1954 to the OH molecule 1612 MHz spectral line, which is often used for the detection of masers in the circumstellar envelopes of

New evidence for Dicke’s superradiance in the 6.7 GHz methanol spectral line in the interstellar medium

We present new evidence for superradiance in the methanol 6.7 GHz spectral line for three different star-forming regions: S255IR-NIRS3, G24.329+0.144, and Cepheus A. Our analysis shows that some of

Astronomical masers and Dicke’s superradiance

We consider the radiation properties and processes of a gas with a population inversion using the formalism based on the Maxwell-Bloch equations. We focus on the maser action and Dicke's

Explaining fast radio bursts through Dicke's superradiance

Fast Radio Bursts (FRBs), characterized by strong bursts of radiation intensity at radio wavelengths lasting on the order of a millisecond, have yet to be firmly associated with a family, or

Explaining recurring maser flares in the ISM through large-scale entangled quantum mechanical states

The evidence of superradiance in this source suggests the existence of entangled quantum mechanical states, involving a very large number of molecules, over distances of up to a few kilometers in the interstellar medium.

Superradiance from a Relativistic Source

We construct a model of cooperative superradiant emission from a highly relativistic multi-particle source. We revise an existing model of the literature for a relativistic two-level particle, and

Superradiance and anomalous hyperfine splitting in inhomogeneous ensembles

Collective effects in the interaction of light with ensembles of identical scatterers play an important role in many fields of physics. However, often the term “identical” is not accurate due to the

Triggered superradiance and fast radio bursts

In this paper we develop a model for fast radio bursts (FRBs) based on triggered superradiance (SR) and apply it to previously published data of FRB 110220 and FRB 121102. We show how a young pulsar

A simple relationship for the spectro-temporal structure of bursts from FRB 121102

We consider a simple dynamical and relativistic model to explain the spectro-temporal structure often displayed by repeating fast radio bursts (FRBs). We show how this model can account for the



Theory of superradiance in an extended, optically thick medium

This paper presents a semiclassical treatment of the evolution of an initially inverted system into a superradiant state in an extended, optically thick medium. In this process spontaneous emission

Methanol masers and millimetre lines: a common origin in protostellar envelopes

Abstract To understand the origin of the CH3OH maser emission, we map the distribution and excitation of the thermal CH3OH emission in a sample of 14 relatively nearby (<6 kpc) high-mass star forming

Physical Conditions in Orion’s Veil. II. A Multicomponent Study of the Line of Sight toward the Trapezium

Orion's Veil is an absorbing screen that lies along the line of sight to the Orion H II region. It consists of two or more layers of gas that must lie within a few parsecs of the Trapezium cluster.

Is Interstellar Hydrogen capable of Maser Action at 21 Centimetres?

THREE sets of observations suggest that the density of interstellar neutral hydrogen may be less than the value usually inferred from 21 cm emission line measurements. This possible discrepancy is

Polarization of Class I methanol (CH3OH) masers

  • A. Sarma
  • Physics
    Proceedings of the International Astronomical Union
  • 2012
Abstract Magnetic fields are known to play an important role in several stages of the star formation process. Class I methanol (CH3OH) masers offer the possibility of measuring the large-scale

Excitation of the Hydrogen 21-CM Line

  • G. Field
  • Physics
    Proceedings of the IRE
  • 1958
The importance of spin temperature for 21-cm line studies is reviewed, and four mechanisms which affect it are studied. Two of the mechanisms, collisions with free electrons and interactions with

A Population of Fast Radio Bursts at Cosmological Distances

The detection of four nonrepeating radio transient events with millisecond duration in data from the 64-meter Parkes radio telescope in Australia indicates that these radio bursts had their origin outside the authors' galaxy, but it is not possible to tell what caused them.

Superradiant emission dynamics of an optically thin material sample in a short-decay-time optical cavity

We report observations of optical superradiant emission and the atomic evolution it drives under conditions closely approximating those originally envisioned in the classic work of Dicke [Phys. Rev.