How the existence of unstable neutral media restricts the aspect ratio of cold neutral media?

Ho, Ka Wai; Yuen, Ka Ho; Lazarian, Alex

doi:10.1093/mnras/stad481

Title: How the existence of unstable neutral media restricts the aspect ratio of cold neutral media?

Journal Article · 14 February 2023 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stad481 · OSTI ID:1959884

Ho, Ka Wai;

; Lazarian, Alex

ABSTRACT The ubiquity of very thin and lengthy cold neutral medium (CNM) has been reported by multiple authors in the H i community. Yet, the reason of how the CNM can be so long and lengthy is still in debate. In this paper, we recognize a new type of instability due to the attractive nature of the pressure force in the unstable phase. We provide a new estimation of the average CNM filament aspect ratio with the consideration of force balances at the phase boundary, which is roughly 5–20 in common CNM environment. We show that most of the cold filaments are less filamentary than what usually predicted via MHD turbulence theory or inferred from observations: The average length of CNM filament is roughly 1/2 of that in isothermal MHD turbulence with similar turbulence conditions. This suggests that the ‘cold filaments’ that are identified in observations might not be in pressure equilibrium or generated via other mechanisms.

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Sponsoring Organization:: USDOE

OSTI ID:: 1959884

Journal Information:: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 1 Vol. 521; ISSN 0035-8711

Publisher:: Oxford University PressCopyright Statement

Country of Publication:: United Kingdom

Language:: English

References (41)

Compressible magnetohydrodynamic turbulence: mode coupling, scaling relations, anisotropy, viscosity-damped regime and astrophysical implications Cho, Jungyeon; Lazarian, A. Monthly Notices of the Royal Astronomical Society, Vol. 345, Issue 1 https://doi.org/10.1046/j.1365-8711.2003.06941.x	journal	October 2003
GASS: The Parkes Galactic All-Sky Survey: Update: improved correction for instrumental effects and new data release Kalberla, P. M. W.; Haud, U. Astronomy & Astrophysics, Vol. 578 https://doi.org/10.1051/0004-6361/201525859	journal	June 2015
The HI/OH/Recombination line survey of the inner Milky Way (THOR) Beuther, H.; Bihr, S.; Rugel, M. Astronomy & Astrophysics, Vol. 595 https://doi.org/10.1051/0004-6361/201629143	journal	October 2016
H i anisotropies associated with radio-polarimetric filaments Kalberla, P. M. W.; Kerp, J.; Haud, U. Astronomy & Astrophysics, Vol. 607 https://doi.org/10.1051/0004-6361/201629627	journal	October 2017
Properties of cold and warm H I gas phases derived from a Gaussian decomposition of HI4PI data Kalberla, P. M. W.; Haud, U. Astronomy & Astrophysics, Vol. 619 https://doi.org/10.1051/0004-6361/201833146	journal	November 2018
The HI/OH/Recombination line survey of the inner Milky Way (THOR): data release 2 and H I overview Wang, Y.; Beuther, H.; Rugel, M. R. Astronomy & Astrophysics, Vol. 634 https://doi.org/10.1051/0004-6361/201937095	journal	February 2020
The history of dynamics and stellar feedback revealed by the H I filamentary structure in the disk of the Milky Way Soler, J. D.; Beuther, H.; Syed, J. Astronomy & Astrophysics, Vol. 642 https://doi.org/10.1051/0004-6361/202038882	journal	October 2020
Local H I filaments driven by a small-scale dynamo Kalberla, P. M. W.; Kerp, J.; Haud, U. Astronomy & Astrophysics, Vol. 654 https://doi.org/10.1051/0004-6361/202140274	journal	October 2021
The filamentary structures in the CO emission toward the Milky Way disk Soler, J. D.; Beuther, H.; Syed, J. Astronomy & Astrophysics, Vol. 651 https://doi.org/10.1051/0004-6361/202141327	journal	July 2021
Thermal Instability. Field, George B. The Astrophysical Journal, Vol. 142 https://doi.org/10.1086/148317	journal	August 1965
Dynamics of fronts in thermally bistable fluids Elphick, Christian; Regev, Oded; Shaviv, Nir The Astrophysical Journal, Vol. 392 https://doi.org/10.1086/171410	journal	June 1992
Toward a theory of interstellar turbulence. 2: Strong alfvenic turbulence Goldreich, P.; Sridhar, S. The Astrophysical Journal, Vol. 438 https://doi.org/10.1086/175121	journal	January 1995
New Temperatures of Diffuse Interstellar Gas: Thermally Unstable Gas Heiles, Carl The Astrophysical Journal, Vol. 551, Issue 1 https://doi.org/10.1086/319844	journal	April 2001
An Origin of Supersonic Motions in Interstellar Clouds Koyama, Hiroshi; Inutsuka, Shu-ichiro The Astrophysical Journal, Vol. 564, Issue 2 https://doi.org/10.1086/338978	journal	January 2001
The Millennium Arecibo 21 Centimeter Absorption‐Line Survey. II. Properties of the Warm and Cold Neutral Media Heiles, Carl; Troland, T. H. The Astrophysical Journal, Vol. 586, Issue 2 https://doi.org/10.1086/367828	journal	April 2003
Neutral Atomic Phases of the Interstellar Medium in the Galaxy Wolfire, Mark G.; McKee, Christopher F.; Hollenbach, David The Astrophysical Journal, Vol. 587, Issue 1 https://doi.org/10.1086/368016	journal	April 2003
The Effect of Anisotropic Conduction on the Thermal Instability in the Interstellar Medium Choi, Ena; Stone, James M. The Astrophysical Journal, Vol. 747, Issue 2 https://doi.org/10.1088/0004-637X/747/2/86	journal	February 2012
Self-Sustained Turbulence Without Dynamical Forcing: a Two-Dimensional Study of a Bistable Interstellar Medium Iwasaki, Kazunari; Inutsuka, Shu-ichiro The Astrophysical Journal, Vol. 784, Issue 2 https://doi.org/10.1088/0004-637X/784/2/115	journal	March 2014
Magnetically Aligned h i Fibers and the Rolling Hough Transform Clark, S. E.; Peek, J. E. G.; Putman, M. E. The Astrophysical Journal, Vol. 789, Issue 1 https://doi.org/10.1088/0004-637X/789/1/82	journal	June 2014
The structure and statistics of interstellar turbulence Kritsuk, A. G.; Ustyugov, S. D.; Norman, M. L. New Journal of Physics, Vol. 19, Issue 6 https://doi.org/10.1088/1367-2630/aa7156	journal	June 2017
EXCITATION TEMPERATURE OF THE WARM NEUTRAL MEDIUM AS A NEW PROBE OF THE Lyα RADIATION FIELD Murray, Claire E.; Lindner, Robert R.; Stanimirović, Snežana The Astrophysical Journal, Vol. 781, Issue 2 https://doi.org/10.1088/2041-8205/781/2/L41	journal	January 2014
Complexity from thermal instability Elphick, C.; Regev, O.; Spiegel, E. A. Monthly Notices of the Royal Astronomical Society, Vol. 250, Issue 3 https://doi.org/10.1093/mnras/250.3.617	journal	June 1991
Inefficient star formation through turbulence, magnetic fields and feedback Federrath, Christoph Monthly Notices of the Royal Astronomical Society, Vol. 450, Issue 4 https://doi.org/10.1093/mnras/stv941	journal	May 2015
Neutral Hydrogen Structures Trace Dust Polarization Angle: Implications for Cosmic Microwave Background Foregrounds Clark, S. E.; Hill, J. Colin; Peek, J. E. G. Physical Review Letters, Vol. 115, Issue 24 https://doi.org/10.1103/PhysRevLett.115.241302	journal	December 2015
Structure of dynamical condensation fronts in the interstellar medium: Structure of dynamical condensation fronts Iwasaki, Kazunari; Inutsuka, Shu-ichiro Monthly Notices of the Royal Astronomical Society, Vol. 423, Issue 4 https://doi.org/10.1111/j.1365-2966.2012.21156.x	journal	June 2012
Dispersal of molecular clouds by ionizing radiation: Dispersal of molecular clouds by ionising radiation Walch, S. K.; Whitworth, A. P.; Bisbas, T. Monthly Notices of the Royal Astronomical Society, Vol. 427, Issue 1 https://doi.org/10.1111/j.1365-2966.2012.21767.x	journal	November 2012
The H i Distribution of the Milky Way Kalberla, Peter M. W.; Kerp, Jürgen Annual Review of Astronomy and Astrophysics, Vol. 47, Issue 1 https://doi.org/10.1146/annurev-astro-082708-101823	journal	September 2009
COLD MILKY WAY H i GAS IN FILAMENTS Kalberla, P. M. W.; Kerp, J.; Haud, U. The Astrophysical Journal, Vol. 821, Issue 2 https://doi.org/10.3847/0004-637X/821/2/117	journal	April 2016
ANALYTIC H i-to-H ₂ PHOTODISSOCIATION TRANSITION PROFILES Bialy, Shmuel; Sternberg, Amiel The Astrophysical Journal, Vol. 822, Issue 2 https://doi.org/10.3847/0004-637X/822/2/83	journal	May 2016
Tracing Magnetic Fields with Spectroscopic Channel Maps Lazarian, A.; Yuen, Ka Ho The Astrophysical Journal, Vol. 853, Issue 1 https://doi.org/10.3847/1538-4357/aaa241	journal	January 2018
Numerical Simulations of Multiphase Winds and Fountains from Star-forming Galactic Disks. I. Solar Neighborhood TIGRESS Model Kim, Chang-Goo; Ostriker, Eve C. The Astrophysical Journal, Vol. 853, Issue 2 https://doi.org/10.3847/1538-4357/aaa5ff	journal	February 2018
On the Formation of Density Filaments in the Turbulent Interstellar Medium Xu, Siyao; Ji, Suoqing; Lazarian, A. The Astrophysical Journal, Vol. 878, Issue 2 https://doi.org/10.3847/1538-4357/ab21be	journal	June 2019
Mapping the Magnetic Interstellar Medium in Three Dimensions over the Full Sky with Neutral Hydrogen Clark, S. E.; Hensley, Brandon S. The Astrophysical Journal, Vol. 887, Issue 2 https://doi.org/10.3847/1538-4357/ab5803	journal	December 2019
Technique for Separating Velocity and Density Contributions in Spectroscopic Data and Its Application to Studying Turbulence and Magnetic Fields Yuen, Ka Ho; Ho, Ka Wai; Lazarian, Alex The Astrophysical Journal, Vol. 910, Issue 2 https://doi.org/10.3847/1538-4357/abe4d4	journal	April 2021
The GALFA-H i Survey Data Release 2 Peek, J. E. G.; Babler, Brian L.; Zheng, Yong The Astrophysical Journal Supplement Series, Vol. 234, Issue 1 https://doi.org/10.3847/1538-4365/aa91d3	journal	December 2017
The 21-SPONGE H i Absorption Line Survey. I. The Temperature of Galactic H i Murray, Claire E.; Stanimirović, Snežana; Goss, W. M. The Astrophysical Journal Supplement Series, Vol. 238, Issue 2 https://doi.org/10.3847/1538-4365/aad81a	journal	September 2018
Lyα Radiative Transfer: Monte Carlo Simulation of the Wouthuysen–Field Effect Seon, Kwang-il; Kim, Chang-Goo The Astrophysical Journal Supplement Series, Vol. 250, Issue 1 https://doi.org/10.3847/1538-4365/aba2d6	journal	August 2020
Tracing Interstellar Magnetic Field Using Velocity Gradient Technique: Application to Atomic Hydrogen Data Yuen, Ka Ho; Lazarian, A. The Astrophysical Journal, Vol. 837, Issue 2 https://doi.org/10.3847/2041-8213/aa6255	journal	March 2017
Cloud Coalescence: A Dynamical Instability Affecting Multiphase Environments Waters, Tim; Proga, Daniel The Astrophysical Journal, Vol. 876, Issue 1 https://doi.org/10.3847/2041-8213/ab12e8	journal	April 2019
Small-scale H i Channel Map Structure Is Cold: Evidence from Na i Absorption at High Galactic Latitudes Peek, J. E. G.; Clark, S. E. The Astrophysical Journal, Vol. 886, Issue 1 https://doi.org/10.3847/2041-8213/ab53de	journal	November 2019
The Discovery of the Largest Gas Filament in Our Galaxy, or a New Spiral Arm? Li, Chong; Qiu, Keping; Hu, Bo The Astrophysical Journal Letters, Vol. 918, Issue 1 https://doi.org/10.3847/2041-8213/ac19bc	journal	August 2021

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