English
Related papers

Related papers: Interpreting The HI Column Density Power Spectrum

200 papers

The neutral hydrogen (HI) power spectrum, measured from intensity fluctuations in the 21-cm background, offers insights into the large-scale structures (LSS) of our Universe in the post-reionization era (redshift $z<6$). A significant…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-10 Mohd Kamran , Martin Sahlén , Debanjan Sarkar , Suman Majumdar

We investigate the scale dependence of fluctuations inside a realistic model of an evolving turbulent HII region and to what extent these may be studied observationally. We find that the multiple scales of energy injection from champagne…

Astrophysics of Galaxies · Physics 2015-06-22 S. -N. X. Medina , S. J. Arthur , W. J. Henney , G. Mellema , A. Gazol

The Fourier power spectrum is one of the most widely used statistical tools to analyze the nature of magnetohydrodynamic turbulence in the interstellar medium. Lazarian & Pogosyan (2004) predicted that the spectral slope should saturate to…

Astrophysics of Galaxies · Physics 2015-06-15 Blakesley Burkhart , A. Lazarian , V. Ossenkopf , J. Stutzki

The turbulent dynamics of nearby and extragalactic gas structures can be studied with the column density power spectrum, which is often described by a broken power-law.In an extragalactic context, the breaks in the power spectra have been…

Astrophysics of Galaxies · Physics 2021-06-09 Bastian Körtgen , Nickolas Pingel , Nicholas Killerby-Smith

The paper analyzes the absorption line profile at 21 cm for the hydrogen atom in the interstellar medium. The hydrogen atom is treated as a three-level system illuminated by a powerful light source at neighboring resonances corresponding to…

Atomic Physics · Physics 2018-11-05 D. Solovyev

Power induced wave collapse is one of the most fascinating phenomena in optics as it provides extremely high intensities, thus stimulating a range of nonlinear processes. For low power levels, propagation of beams in bulk media is dominated…

By means of three dimensional high-resolution hybrid simulations we study the properties of the magnetic field spectral anisotropies near and beyond ion kinetic scales. By using both a Fourier analysis and a local analysis based on…

Solar and Stellar Astrophysics · Physics 2019-04-18 Simone Landi , Luca Franci , Emanuele Papini , Andrea Verdini , Lorenzo Matteini , Petr Hellinger

21 cm power spectrum observations have the potential to revolutionize our understanding of the Epoch of Reionization and Dark Energy, but require extraordinarily precise data analysis methods to separate the cosmological signal from the…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-31 Miguel F. Morales , Adam Beardsley , Jonathan Pober , Nichole Barry , Bryna Hazelton , Daniel Jacobs , Ian Sullivan

We consider the two-dimensional (2D) flow in a flat free-slip surface that bounds a three-dimensional (3D) volume in which the flow is turbulent. The equations of motion for the two-dimensional flow in the surface are neither compressible…

Chaotic Dynamics · Physics 2009-11-07 Bruno Eckhardt , Joerg Schumacher

The high-redshift 21-cm signal of neutral hydrogen is expected to be observed within the next decade and will reveal epochs of cosmic evolution that have been previously inaccessible. Due to the lack of observations, many of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-16 Aviad Cohen , Anastasia Fialkov , Rennan Barkana

Fluctuations in high-redshift cosmic 21-cm radiation provide a new window for observing unconventional effects of high-energy physics in the primordial spectrum of density perturbations. In scenarios for which the initial state prior to…

High Energy Physics - Theory · Physics 2008-11-26 Matthew Kleban , Kris Sigurdson , Ian Swanson

The nature of turbulence in the warm ionized component of the interstellar medium (WIM) can be investigated using Fabry-Perot spectroscopy of optical emission lines. The H-alpha intensity provides the emission measure (EM) along a line of…

Astrophysics · Physics 2007-05-23 S. L. Tufte , R. J. Reynolds , L. M. Haffner

Our ability to correct the observational photometry of galaxies depends upon our knowledge of the attenuation of light produced by the dust contained in the interstellar medium. We will present a model based on the statistical properties of…

Astrophysics · Physics 2009-11-10 Joerg Fischera

The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated. Through the ultrasonic signals emitted by the filaments, and it is observed that increasing…

We study the effect of density fluctuations induced by turbulence on the HI/H$_2$ structure in photodissociation regions (PDRs) both analytically and numerically. We perform magnetohydrodynamic numerical simulations for both subsonic and…

Astrophysics of Galaxies · Physics 2017-07-26 Shmuel Bialy , Blakesley Burkhart , Amiel Sternberg

One of the main challenges for future 21 cm observations is to remove foregrounds which are several orders of magnitude more intense than the HI signal. We propose a new technique for removing foregrounds of the redshifted 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jungyeon Cho , A. Lazarian , P. Timbie

It was shown previously that the current-carrying state of a Field Effect Transistor with asymmetric source and drain boundary conditions may become unstable against spontaneous generation of plasma waves [1]. By extending the analysis to…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 M. I. Dyakonov

Diffuse Galactic light has been observed in the optical since the 1930s. We propose that, when observed in the optical with deep imaging surveys, it can be used as a tracer of the turbulent cascade in the diffuse interstellar medium (ISM),…

Astrophysics of Galaxies · Physics 2016-08-31 M. -A. Miville-Deschenes , P. -A. Duc , F. Marleau , J. -C. Cuillandre , P. Didelon , S. Gwyn , E. Karabal

Modern radio spectrometers make measurement of polarized intensity as a function of Faraday depth possible. I investigate the effect of depolarization along a model line of sight. I model sightlines with two components informed by…

Astrophysics of Galaxies · Physics 2018-12-04 A. S. Hill

Astrophysical fluids, including interstellar and interplanetary medium, are magnetized and turbulent. Their appearance, evolution, and overall properties are determined by the magnetic turbulence that stirs it. We argue that examining…

Astrophysics · Physics 2009-11-13 A. Lazarian , A. Beresnyak , H. Yan , M. Opher , Y. Liu