LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Leeuw, Lerothodi Leonard
Languages: English
Types: Doctoral thesis
Subjects: F500

Classified by OpenAIRE into

arxiv: Astrophysics::Galaxy Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Solar and Stellar Astrophysics
The thesis presents millimetre (mm) and submm continuum imaging observations of the\ud four, nearby active galaxies Cygnus A, NCC 4374, Centaurus A and M 82. These were\ud undertaken using the Submillimetre Common-User Bolometer Array (SCUBA) on the\ud James Clerk Maxwell Telescope in Hawaii. The study focused on the properties of the\ud cool to cold dust (~ 80 to 10K) and its associations with star formation and nuclear\ud activity in the galaxies.\ud \ud The observations of Cygnus A constrained the galaxy's cold dust temperature between\ud 37 and 85K, corresponding to dust masses between 1.0 x 10 8M® and 1.4 x 106M®\ud respectively. Based on the dust spatial and mass limits, it is possible the heating of the\ud cold dust in Cygnus A is dominated by high-energy nuclear activity or star formation.\ud Detailed photometric observations of the core and two major hotspots (A and D) in\ud Cygnus A showed that their mm to submm spectral indices extend smoothly to about\ud 450μm (677GHz), with no evidence of spectral steepening. The results allow tight determinations\ud for model parameters of synchrotron electron lifetimes in these components.\ud \ud In pilot survey observations of the elliptical galaxy NGC 4374, a mass upper-limit\ud Of ~ 2 x 107M® (i.e. comparable to the dust contents of luminous spiral galaxies) was\ud placed on the diffuse dust that, if it exists, would affect colour and metallicity studies of elliptical galaxies. Following the pilot observations, a strategy was devised to select a good sample of ellipticals in which to search for this low-level, very cold dust.\ud \ud For the first time ever, the observations of Centaurus A delineated the galaxy's submm\ud unresolved core, an inner-jet interacting with gas in the dust lane, and extended emission\ud from multi-temperature cold dust at ~ 40, 30 and 12K. Also for the first time ever, a\ud submm high surface brightness ringed, spiral structure of radii ~ 90", that coincides with\ud the regions of intense star formation and mid-infrared continuum, was revealed in the\ud optical dust-lane, confirming predictions by a geometric warped disc model consisting of\ud tilted rings. From the spatial associations in the galaxy, star formation seems to dominate\ud at lease 50% of the heating of the cold dust, while the rest appears to be heated by diluted\ud stellar radiation. \ud \ud In M82, the 850μm continuum has been detected out to 1.5kpc, at least 10% farther\ud in radius than previous detections in this starburst galaxy. The overall submm morphology\ud and nuclear spectral index distribution have a general north-south asymmetry similar\ud to that of H. and X-ray winds, supporting the association of the extended continuum\ud with outflows of dust grains from the nucleus into the halo. The work of M 82 raises many\ud interesting points about the origin and structure of the submm emission, however the\ud results are displayed here still under investigation and therefore are rather preliminary. \ud \ud In short, the submm continuum observations of Cygnus A, NGC 4374, CentaurusA\ud and M 82 are presented in this thesis that constrain the physical properties of cold dust\ud in these active galaxies and elucidate the associations of the dust with star formation,\ud nuclear activity and stellar components in these galaxies in particular, and other similar\ud galaxies in general.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • 3 Millimetre and Submillimetre Continuum Observations of the Core and Hotspots of Cygnus A 34 3.1 Introduction ...................................34 3.2 Observations ..................................36 3.3 Results and Discussion .............................42 3.3.1 The Hotspots ..............................42 3.3.2 The Core Component .........................44 3.3.3 Cold Dust in Cygnus A ........................45 3.4 Summary ....................................48
    • 4 SCUBA Observations of the Elliptical Galaxy NGC 4374 50 4.1 Introduction ...................................50 4.2 Observations and Reductions .........................53 4.3 Results and Discussion .............................54
    • 4.3.1 Decomposing the SED . 56
    • 4.3.2 Dust Mass and its Implications ....................61
    • Conclusions ...................................63
    • 5 Direct Imaging of Cold Dust Structures in Centaurus A 65 5.1 Introduction ...................................65 5.2 Observations ..................................67 5.3 The Submm Images and Comparisons with other Wavelengths ......69 5.3.1 Submm vs. Optical Morphology ...................76 5.3.2 Submm vs. ISO Mid-JR Morphology ................78 5.3.3 Submm vs. IRAS Far-JR Morphology ................79 5.3.4 Submm vs. Warped-Disc-Model Morphology ............82 5.4 The Submm Spectral Index Distribution ...................87 5.5 Implications of the Multiwavelength Images .................92 5.6 The Extended Emission Temperature and Dust Mass Estimates ......95 5.7 The Unresolved Core: Radio to Optical SED ................99 5.8 Conclusions ...................................101
    • 6 Properties and Outflows of Cold Dust in M 82 104 6.1 Introduction ...................................104 6.2 Observations ..................................110 6.3 The General Submm Continuum Morphology ................111 6.3.1 Submm vs. Optical Morphology ...................114 6.3.2 Submm vs. High-Resolution CO (1-0) Morphology .........116 6.4 The Nuclear Spectral Index Distribution ...................119
    • 2.1 Overview of JCMT and Atmospheric Parameters ..............19
    • 2.2 Typical CSO relations used in this thesis project ..............28
    • 2.3 New CSO relations derived October 2000 by JCMT staff ..........29
    • 2.4 Illustrative HIRES Resolutions after 1 and 20 iterations ..........33
    • 3.1 SCUBA Fluxes of Cygnus A's Core and Hotspots ..............38
    • 4.1 Submillimetre fluxes for NGC 4374 from SCUBA ..............54
    • 4.2 Parameters determined from the model fit to the SED for NOC 4374 . . . 61
    • Barger, A. J., Cowie, L. L., Sanders, D. B., Fulton, E., Taniguchi, Y., Sato, Y., Kawara, K., & Okuda, H. 1998, Nature, 394, 248
    • Bolton, J. G., Stanley, C. J., & Slee, 0. B. 1949, Nature, 164, 101
    • Bower, G. A., Heckman, T. M., Wilson, A. S., & Richstone, D. 0. 1997, ApJ, 483, L33
    • Bradford, C. M., Stacey, C. J., Nikola, T., Swain, M. R., Bolatto, A. D., Jackson, J. M., Savage, M. L., & Davidson, J. A. 1999, in American Astronomical Society Meeting, Vol. 195, 7304
    • Bridle, A. H. & Perley, R. A. 1984, ARA&A, 22, 319
    • Brodie, J., Koenigl, A., & Bowyer, S. 1983, ApJ, 273, 154
    • Brown, L. M. J., Robson, E. I., Gear, W. K., & Smith, M. C. 1989, ApJ, 340,150
    • Bryant, J. J. & Hunstead, R. W. 1999, MNRAS, 308, 431
    • Canizares, C. R., Fabbiano, C., & Trinchieri, C. 1987, ApJ, 312, 503
    • Carilli, C. L. & Barthel, P. D. 1996, A&A Rev., 7, 1
    • Carilli, C. L. & Harris, D. E. 1996, Cygnus A - Study of a Radio Galaxy (Cambridge University Press)
    • Carilli, C. L., Kurk, J. D., van der Werl, P. P., Perley, R. A., & Miley, C. K. 1999, AJ, 118, 2581
    • Carilli, C. L., Perley, R., Harris, D. EL, & Barthel, P. D. 1998, Physics of Plasmas, Volume 5, Issue 5, May 1998, pp.1981-1990, 5, 1981
    • Chevalier, R. A. & Clegg, A. W. 1985, Nature, 317, 44
    • Clarke, D. A., Burns, J. 0., & Norman, M. L. 1992, ApJ, 395, 444
    • Cunningham, C. T., Ade, P. A. R., Robson, E. I., & Radostitz, J. V. 1984, MNRAS, 211, 543
    • de Grijs, R. 2001, Astronomy and Geophysics, 42, 12
    • Deutsch, M. & Bicay, M. D. 2000, Ap&SS, 273, 187
    • Dietz, R. D., Gehrz, R. D., Jones, T. J., Grasdajen, C. L., Smith, J., Gullixson, C., & Hackwell, J. A. 1989, AJ, 98, 1260
    • Dietz, R. D., Smith, J., Hackwell, J. A., Gehrz, R. D., & Grasdalen, G. L. 1986, AJ, 91, 758
    • Draine, B. T. 1990, in ASSL Vol. 161: The Interstellar Medium in Galaxies, 483-492
    • Duncan, W. D., Sandell, 0., Robson, E. I., Ade, P. A. R., & Griffin, M. J. 1990, MNRAS, 243, 126
    • Edmunds, M. G. & Eales, S. A. 1998, MNRAS, 299, L29
    • Emerson, J. P., Clegg, P. E., Gee, 0., Griffin, M. J., Cunningham, C. T., Brown, L. M. J., Robson, E. I., & Longmore, A. J. 1984, Nature, 311, 237
    • Gear, W. K., Robson, E. I., Ade, P. A. R., Smith, M. C., C!egg, P. E., Cunningham, C. T., Griffin, M. J., Nolt, I. G., & Radostitz, J. V. 1984, ApJ, 280, 102
    • Greaves, J. S., Holland, W. S., Moriarty-Schieven, G., Jenness, T., Dent, W. R. F., Zuckerman, B., McCarthy, C., Webb, R. A., Butner, H. M., Gear, W. K., & Walker, H. J. 1998, ApJ, 506, L133
    • Griffin, M. J. & Orton, G. S. 1993, Icarus, 105, 537
    • Guesten, R., Serabyn, E., Kasemann, C., Schinckel, A., Schneider, G., Schulz, A., & Young, K. 1993, ApJ, 402, 537
    • Gull, S. F. & Skilling, J. 1983, in Indirect Imaging - Measurement and Processing for Indirect Imaging. Proceedings of an International Symposium held in Sydney, Australia, August 30-September 2, 1983. Editor, J.A. Roberts; Publisher, Cambridge University Press, Cambridge, England, 267
    • Hass, M., Chini, R., Meisenheimer, K., Stickel, M., Lemke, D., Klaas, U., & Kreysa, E. 1998, ApJ, 503, L109
    • Hajian, A. R. ., Phillips, J. A., & Terzian, Y. 1996, ApJ, 467, 341
    • Hajian, A. R., Phillips, J. A., & Terzian, Y. 1995, ApJ, 446, 244
    • Hawarden, T. G., Sandell, G, Matthews, H. E., Friberg, P., Watt, G. D., & Smith, P. A. 1993, MNRAS, 260,844
    • Ho, L. C., Filippenko, A. V., & Sargent, W. L. W. 1996, in ASP Conf. Ser. 91: IAU Colloq. 157: Barred Galaxies, 188
    • Holland, W. S., Greaves, J. S., Zuckerman, B., Webb, R. A., McCarthy, C., Coulson, I. M., Waither, D. M., Dent, W. R. F., Gear, W. K., & Robson, I. 1998, Nature, 392,
    • Holland, W. S., Robson, E. I., Gear, W. K., Cunningham, C. R., Lightfoot, J. F., Jenness, T., Ivison, R. J., Stevens, J. A., Ade, P. A. R., Griffin, M. J., Duncan, W. D., Murphy, J. A., & Naylor, D. A. 1999, MNRAS, 303, 659
    • Hughes, D. H., Dunlop, J. S., & Rawlings, S. 1997, MNRAS, 289, 766
    • Hughes, D. H., Gear, W. K., & Robson, E. I. 1994, MNRAS, 270, 641
    • Hughes, D. H., Robson, E. I., Dunlop, J. S., & Gear, W. K. 1993, MNRAS, 263, 607
    • Hughes, D. H., Robson, E. I., & Gear, W. K. 1990, MNRAS, 244, 759
    • Hughes, D. H., Serjeant, S., Dunlop, J., Rowan-Robinson, M., Blain, A., Mann, R. G., Ivison, R., Peacock, J., Efstathiou, A., Gear, W., Oliver, S., Lawrence, A., Longair, M., Goldschmjdt, P., & Jenness, T. 1998, Nature, 394, 241
    • Hui, X., Ford, H. C., Ciardullo, R., & Ja.coby, G. H. 1993, ApJ, 414, 463
    • Joy, M., Harvey, P. M., Tollestrup, E. V., Sellgren, K., McGregor, P. J., & Hyland, A. R. 1991, ApJ, 366, 82
    • Kellermann, K. I., Zensus, J. A., & Cohen, M. H. 1997, ApJ, 475, L93
    • Klaas, U., Haas, M., Heinrichsen, I., & Schulz, B. 1997, A&A, 325, L21
    • Knapp, G. R., Bies, W. E., & van Gorkom, J. H. 1990, AJ, 99, 476
    • Knapp, C. R. & Patten, B. M. 1991, AJ, 101, 1609
    • Kraft, R. P., Forman, W., Jones, C., Kenter, A. T., Murray, S. S., Aldcroft, T. L., Elvis, M. S., Evans, I. N., Fabbiano, G., Isobe, T., Jerius, D., Karovska, M., Kim, D., Prestwich, A. H., Primini, F. A., Schwartz, D. A., Schreier, E. J., & Vikhlinin, A. A. 2000, ApJ, 531, L9
    • Krichbaum, T. P., Alef, W., Witzel, A., Zensus, J. A., Booth, R. S., Greve, A., & Rogers, A. E. E. 1998, A&A, 329, 873
    • Kronberg, P. P., Biermann, P., & Schwab, F. R. 1985, ApJ, 291, 693
    • Leeuw, L. L. & Robson, E. I. 1999, in IAU Symp. 194: Activity in Galaxies and Related Phenomena, Vol. 194, 179
    • Leeuw, L. L. & Robson, E. 1. 2000, in Imaging at Radio through Submillimeter Wavelengths. Edited by Jeff Mangum. Publisher: The Astronomical Society of the Pacific, Conference Series, 2000. The conference was held June 6-8, 1999, in Tucson, Arizona., E40
    • Leeuw, L. L., Sansom, A. E., & Robson, E. I. 2000, MNRAS, 311, 683
    • Mirabel, I. F., Laurent, 0., Sanders, D..B., Sauvage, M., Tagger, M., Charmandaris, V., Vigroux, L., Gallais, P., Cesarsky, C., & Block, D. L. 1999, A&A, 341, 667
    • Moran, J. M. 1996, in American Astronomical Society Meeting, Vol. 188, 4605
    • Muxiow, T. W. B., Pedlar, A., Wilkinson, P. N., Axon, D. J., Sanders, E. M., & de Bruyn, A. G. 1994, MNRAS, 266, 455
    • Nakai, N., Hayashi, M., Handa, T., Sofue, Y., Hasegawa, T., & Sasaki, M. 1987, PASJ, 39,685
    • Neininger, N., Guelin, M., Klein, U., Garcia-Burillo, S., & Wielebinski, R. 1998, A&A, 339, 737
    • Nicholson, R. A., Bland-Hawthorn, J., & Taylor, K. 1992, ApJ, 387, 503
    • Schreier, E. J., Capetti, A., Macchetto, F., Sparks, W. B., & Ford, H. J. 1998, STScI Electronic Press Release STScJ-PRC98-14, 459, 535
    • Seaquist, E. R. & Clark, J. 2001, ApJ, 552, 133
    • Seaquist, E. R. & Odegard, N. 1991, Ap.J, 369, 320
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article