Nature of Supersonic Turbulence and Density Distribution Function in the Multiphase Interstellar Medium

被引：12

作者：

Kobayashi, Masato I. N. ^{[1
,2
]}

Inoue, Tsuyoshi ^{[3
,4
]}

Tomida, Kengo ^{[2
]}

Iwasaki, Kazunari ^{[1
,5
]}

Nakatsugawa, Hiroki ^{[3
]}

机构：

[1] Natl Astron Observ Japan, Div Sci, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan

[2] Tohoku Univ, Grad Sch Sci, Astron Inst, Aoba Ku, Sendai, Miyagi 9808578, Japan

[3] Nagoya Univ, Grad Sch Sci, Div Particle & Astrophys Sci, Nagoya, Aichi 4648602, Japan

[4] Konan Univ, Dept Phys, Okamoto 8-9-1, Kobe, Hyogo, Japan

[5] Natl Astron Observ Japan, Ctr Computat Astrophys, Mitaka, Tokyo 1818588, Japan

来源：

ASTROPHYSICAL JOURNAL | 2022年 / 930卷 / 01期

关键词：

MOLECULAR CLOUD FORMATION; PROBABILITY-DISTRIBUTION FUNCTIONS; UV-RADIATION FEEDBACK; STAR-FORMATION RATE; MASSIVE STAR; AMBIPOLAR DIFFUSION; PRESTELLAR CORES; ATOMIC-HYDROGEN; MAGNETIC-FIELDS; POWER SPECTRUM;

D O I：

10.3847/1538-4357/ac5a54

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Supersonic flows in the interstellar medium (ISM) are believed to be a key driver of the molecular cloud formation and evolution. Among molecular clouds' properties, the ratio between the solenoidal and compressive modes of turbulence plays important roles in determining the star formation efficiency. We use numerical simulations of supersonic converging flows of the warm neutral medium (WNM) resolving the thermal instability to calculate the early phase of molecular cloud formation, and we investigate the turbulence structure and the density probability distribution function (density PDF) of the multiphase ISM. We find that both the solenoidal and compressive modes have their power spectrum similar to the Kolmogorov spectrum. The solenoidal (compressive) modes account for greater than or similar to 80% (less than or similar to 20%) of the total turbulence power. When we consider both the cold neutral medium (CNM) and the thermally unstable neutral medium (UNM) up to T less than or similar to 400 K, the density PDF follows the lognormal distribution, whose width sigma(s) is well explained by the known relation from the isothermal turbulence as sigma(s) = ln(1 + b(2) M-2) (where b is the parameter representing the turbulence mode ratio and M is the turbulent Mach number). The density PDF of the CNM component alone (T <= 50 K), however, exhibits a narrower sigma(s) by a factor of similar to 2. These results suggest that observational estimations of b based on the CNM density PDF requires the internal turbulence within each CNM clump but not the interclump relative velocity, the latter of which is instead powered by the WNM/UNM turbulence.

引用

页数：14

共 79 条

[1] Planck 2013 results. XXIII. Isotropy and statistics of the CMB [J].

Ade, P. A. R. ;

Aghanim, N. ;

Armitage-Caplan, C. ;

Arnaud, M. ;

Ashdown, M. ;

Atrio-Barandela, F. ;

Aumont, J. ;

Baccigalupi, C. ;

Banday, A. J. ;

Barreiro, R. B. ;

Bartlett, J. G. ;

Bartolo, N. ;

Battaner, E. ;

Battye, R. ;

Benabed, K. ;

Benoit, A. ;

Benoit-Levy, A. ;

Bernard, J. -P. ;

Bersanelli, M. ;

Bielewicz, P. ;

Bobin, J. ;

Bock, J. J. ;

Bonaldi, A. ;

Bonavera, L. ;

Bond, J. R. ;

Borrill, J. ;

Bouchet, F. R. ;

Bridges, M. ;

Bucher, M. ;

Burigana, C. ;

Butler, R. C. ;

Cardoso, J. -F. ;

Catalano, A. ;

Challinor, A. ;

Chamballu, A. ;

Chary, R. -R. ;

Chiang, H. C. ;

Chiang, L. -Y ;

Christensen, P. R. ;

Church, S. ;

Clements, D. L. ;

Colombi, S. ;

Colombo, L. P. L. ;

Couchot, F. ;

Coulais, A. ;

Crill, B. P. ;

Cruz, M. ;

Curto, A. ;

Cuttaia, F. ;

Danese, L. .

ASTRONOMY & ASTROPHYSICS, 2014, 571

[2] Herschel view of the large-scale structure in the Chamaeleon dark clouds [J].

Alves de Oliveira, C. ;

Schneider, N. ;

Merin, B. ;

Prusti, T. ;

Ribas, A. ;

Cox, N. L. J. ;

Vavrek, R. ;

Koenyves, V. ;

Arzoumanian, D. ;

Puga, E. ;

Pilbratt, G. L. ;

Kospal, A. ;

Andre, Ph ;

Didelon, P. ;

Men'shchikov, A. ;

Royer, P. ;

Waelkens, C. ;

Bontemps, S. ;

Winston, E. ;

Spezzi, L. .

ASTRONOMY & ASTROPHYSICS, 2014, 568

[3] From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt Survey [J].

Andre, Ph. ;

Men'shchikov, A. ;

Bontemps, S. ;

Koenyves, V. ;

Motte, F. ;

Schneider, N. ;

Didelon, P. ;

Minier, V. ;

Saraceno, P. ;

Ward-Thompson, D. ;

Di Francesco, J. ;

White, G. ;

Molinari, S. ;

Testi, L. ;

Abergel, A. ;

Griffin, M. ;

Henning, Th. ;

Royer, P. ;

Merin, B. ;

Vavrek, R. ;

Attard, M. ;

Arzoumanian, D. ;

Wilson, C. D. ;

Ade, P. ;

Aussel, H. ;

Baluteau, J. -P. ;

Benedettini, M. ;

Bernard, J. -Ph. ;

Blommaert, J. A. D. L. ;

Cambresy, L. ;

Cox, P. ;

Di Giorgio, A. ;

Hargrave, P. ;

Hennemann, M. ;

Huang, M. ;

Kirk, J. ;

Krause, O. ;

Launhardt, R. ;

Leeks, S. ;

Le Pennec, J. ;

Li, J. Z. ;

Martin, P. G. ;

Maury, A. ;

Olofsson, G. ;

Omont, A. ;

Peretto, N. ;

Pezzuto, S. ;

Prusti, T. ;

Roussel, H. ;

Russeil, D. .

ASTRONOMY & ASTROPHYSICS, 2010, 518

[4] ELECTRON-DENSITY POWER SPECTRUM IN THE LOCAL INTERSTELLAR-MEDIUM [J].

ARMSTRONG, JW ;

RICKETT, BJ ;

SPANGLER, SR .

ASTROPHYSICAL JOURNAL, 1995, 443 (01) :209-221

[5] Thermal condensation in a turbulent atomic hydrogen flow [J].

Audit, E ;

Hennebelle, P .

ASTRONOMY & ASTROPHYSICS, 2005, 433 (01) :1-U20

[6] LOCAL DYNAMIC THERMAL-INSTABILITY [J].

BALBUS, SA .

ASTROPHYSICAL JOURNAL, 1986, 303 (02) :L79-L82

[7] GENERAL LOCAL STABILITY-CRITERIA FOR STRATIFIED, WEAKLY MAGNETIZED ROTATING SYSTEMS [J].

BALBUS, SA .

ASTROPHYSICAL JOURNAL, 1995, 453 (01) :380-383

[8] Cosmic microwave background temperature and polarization pseudo-Cl estimators and covariances [J].

Brown, ML ;

Castro, PG ;

Taylor, AN .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2005, 360 (04) :1262-1280

[9] The density variance - Mach number relation in the Taurus molecular cloud [J].

Brunt, C. M. .

ASTRONOMY & ASTROPHYSICS, 2010, 513

[10] THE EFFECTS OF FLOW-INHOMOGENEITIES ON MOLECULAR CLOUD FORMATION: LOCAL VERSUS GLOBAL COLLAPSE [J].

Carroll-Nellenback, Jonathan J. ;

Frank, Adam ;

Heitsch, Fabian .

ASTROPHYSICAL JOURNAL, 2014, 790 (01)

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