Knowledge

Clumping factor

Source 📝

124: 29: 599: 70: 542: 255:
The amount that gas clumps is important to know in astronomy when trying to infer gas properties from observations. The clumping of gas, and not just the amount of gas present, affects the luminosity of gas as it cools. The clumping factor is a measure of the density variation of a medium. It is
427:
Cooling rates and emission scale as the particle number density squared (collision rates have this scaling). Therefore, the clumping factor can be used to convert from density inferred by emission observations assuming uniform density, to true average gas density:
422: 235:
is a measurement of how density varies within a gaseous medium, and is commonly used in astrophysical settings where gas is not distributed uniformly. Gas densities can vary over many orders of magnitude, from the low density plasma in the
329: 506: 344: 262: 640: 434: 134: 583: 218: 56: 42: 633: 192: 149: 164: 664: 171: 669: 626: 576: 178: 160: 659: 417:{\displaystyle \operatorname {C} (\rho )=\operatorname {Var} (\rho )/\operatorname {E} (\rho )^{2}+1.} 569: 237: 48: 245: 17: 324:{\displaystyle \operatorname {C} (\rho )=\langle \rho ^{2}\rangle /\langle \rho \rangle ^{2}} 185: 549: 80: 610: 553: 99: 653: 524: 606: 123: 525:"Pawlik, A.H., Schaye, J., & van Scherpenzeel, E. 2009, mnras, 394, 1812 " 501:{\displaystyle \rho _{true}={\frac {\rho _{obs}}{\operatorname {C} ^{1/2}}}} 249: 89: 69: 335: 241: 598: 141: 541: 117: 63: 22: 338:
of the density field by the square of the average density:
252:
implying it has density structure on all spatial scales.
614: 557: 145: 94: 84: 248:
inside of galaxies. Moreover, gas throughout space is
437: 347: 265: 244:, to the neutral and dense molecular regions in the 500: 416: 323: 334:where averaging is spatial. It is related to the 634: 577: 8: 312: 305: 297: 284: 150:introducing citations to additional sources 57:Learn how and when to remove these messages 641: 627: 584: 570: 486: 482: 466: 460: 442: 436: 402: 381: 346: 315: 300: 291: 264: 219:Learn how and when to remove this message 140:Relevant discussion may be found on the 517: 7: 595: 593: 538: 536: 479: 386: 348: 266: 14: 38:This article has multiple issues. 597: 540: 133:relies largely or entirely on a 122: 68: 27: 46:or discuss these issues on the 399: 392: 378: 372: 360: 354: 278: 272: 1: 613:. You can help Knowledge by 556:. You can help Knowledge by 686: 592: 535: 15: 16:Not to be confused with 83:, as no other articles 609:-related article is a 552:–related article is a 502: 418: 325: 503: 419: 326: 665:Plasma physics stubs 435: 345: 263: 238:Intergalactic medium 146:improve this article 246:interstellar medium 670:Astrophysics stubs 498: 414: 321: 102:for suggestions. 92:to this page from 622: 621: 565: 564: 496: 229: 228: 221: 211: 210: 196: 161:"Clumping factor" 116: 115: 61: 18:Clumping factor A 677: 643: 636: 629: 601: 594: 586: 579: 572: 544: 537: 527: 522: 507: 505: 504: 499: 497: 495: 494: 490: 477: 476: 461: 456: 455: 423: 421: 420: 415: 407: 406: 385: 330: 328: 327: 322: 320: 319: 304: 296: 295: 224: 217: 206: 203: 197: 195: 154: 126: 118: 111: 108: 97: 95:related articles 72: 64: 53: 31: 30: 23: 685: 684: 680: 679: 678: 676: 675: 674: 650: 649: 648: 647: 591: 590: 533: 531: 530: 523: 519: 514: 478: 462: 438: 433: 432: 398: 343: 342: 311: 287: 261: 260: 233:clumping factor 225: 214: 213: 212: 207: 201: 198: 155: 153: 139: 127: 112: 106: 103: 93: 90:introduce links 73: 32: 28: 21: 12: 11: 5: 683: 681: 673: 672: 667: 662: 652: 651: 646: 645: 638: 631: 623: 620: 619: 602: 589: 588: 581: 574: 566: 563: 562: 550:plasma physics 545: 529: 528: 516: 515: 513: 510: 509: 508: 493: 489: 485: 481: 475: 472: 469: 465: 459: 454: 451: 448: 445: 441: 425: 424: 413: 410: 405: 401: 397: 394: 391: 388: 384: 380: 377: 374: 371: 368: 365: 362: 359: 356: 353: 350: 332: 331: 318: 314: 310: 307: 303: 299: 294: 290: 286: 283: 280: 277: 274: 271: 268: 227: 226: 209: 208: 144:. Please help 130: 128: 121: 114: 113: 107:September 2024 100:Find link tool 76: 74: 67: 62: 36: 35: 33: 26: 13: 10: 9: 6: 4: 3: 2: 682: 671: 668: 666: 663: 661: 660:Space plasmas 658: 657: 655: 644: 639: 637: 632: 630: 625: 624: 618: 616: 612: 608: 603: 600: 596: 587: 582: 580: 575: 573: 568: 567: 561: 559: 555: 551: 546: 543: 539: 534: 526: 521: 518: 511: 491: 487: 483: 473: 470: 467: 463: 457: 452: 449: 446: 443: 439: 431: 430: 429: 411: 408: 403: 395: 389: 382: 375: 369: 366: 363: 357: 351: 341: 340: 339: 337: 316: 308: 301: 292: 288: 281: 275: 269: 259: 258: 257: 256:defined as: 253: 251: 247: 243: 239: 234: 223: 220: 205: 194: 191: 187: 184: 180: 177: 173: 170: 166: 163: –  162: 158: 157:Find sources: 151: 147: 143: 137: 136: 135:single source 131:This article 129: 125: 120: 119: 110: 101: 96: 91: 87: 86: 82: 77:This article 75: 71: 66: 65: 60: 58: 51: 50: 45: 44: 39: 34: 25: 24: 19: 615:expanding it 607:astrophysics 604: 558:expanding it 547: 532: 520: 426: 333: 254: 232: 230: 215: 199: 189: 182: 175: 168: 156: 132: 104: 78: 54: 47: 41: 40:Please help 37: 654:Categories 512:References 202:March 2024 172:newspapers 98:; try the 85:link to it 43:improve it 464:ρ 440:ρ 396:ρ 390:⁡ 376:ρ 370:⁡ 358:ρ 352:⁡ 313:⟩ 309:ρ 306:⟨ 298:⟩ 289:ρ 285:⟨ 276:ρ 270:⁡ 250:turbulent 142:talk page 88:. Please 49:talk page 336:variance 242:galaxies 240:between 186:scholar 188:  181:  174:  167:  159:  81:orphan 79:is an 605:This 548:This 193:JSTOR 179:books 611:stub 554:stub 231:The 165:news 367:Var 148:by 656:: 412:1. 52:. 642:e 635:t 628:v 617:. 585:e 578:t 571:v 560:. 492:2 488:/ 484:1 480:C 474:s 471:b 468:o 458:= 453:e 450:u 447:r 444:t 409:+ 404:2 400:) 393:( 387:E 383:/ 379:) 373:( 364:= 361:) 355:( 349:C 317:2 302:/ 293:2 282:= 279:) 273:( 267:C 222:) 216:( 204:) 200:( 190:· 183:· 176:· 169:· 152:. 138:. 109:) 105:( 59:) 55:( 20:.

Index

Clumping factor A
improve it
talk page
Learn how and when to remove these messages

orphan
link to it
introduce links
related articles
Find link tool

single source
talk page
improve this article
introducing citations to additional sources
"Clumping factor"
news
newspapers
books
scholar
JSTOR
Learn how and when to remove this message
Intergalactic medium
galaxies
interstellar medium
turbulent
variance
"Pawlik, A.H., Schaye, J., & van Scherpenzeel, E. 2009, mnras, 394, 1812 "
Stub icon
plasma physics

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.