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Physical conditions and chemistry of molecular gas in galactic centers

Published online by Cambridge University Press:  22 May 2014

Susanne Aalto
Susanne Aalto*
Affiliation:
Department of Earth and Space Sciences, Chalmers University of TechnologyOnsala Space Observatory, SE-439 92 Onsala, Sweden email: saalto@chalmers.se
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Abstract

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Studying the molecular phase of the interstellar medium in galaxy nuclei is fundamental for the understanding of the onset and evolution of star formation and the growth of supermassive black holes. We can use molecules as observational tools exploiting them as tracers of chemical, physical and dynamical conditions. The molecular physical conditions in galaxy centers show large variety among galaxies, but in general the average gas densities (traced by e.g. HCN) and temperatures (probed by e.g. H2CO, NH3) are greater than in their disks. Molecular gas and dust is being funneled to the centers of galaxies by spiral arms, bars, and interactions - and one example of this is the minor merger NGC1614. Gas surface densities are also greater in galaxy nuclei and in extreme cases they become orders of magnitudes larger than what we find in the center of our own Milky Way. We can use IR excited molecular emission to probe the very inner regions of galaxies with deeply obscured nuclei where N(H2)>1024 cm−2 - for example the luminous infrared galaxy (LIRG) NGC4418. Abundances of key molecules such as HCN, HCO+, HNC, HC3N, CN, H3O+ are important tools in identifying the nature of buried activity and its evolution. Standard astrochemical scenarios (including X-ray Dominated regions (XDRs) and Photon Dominated Regions (PDRs)) are briefly discussed in this review and how we can use molecules to distinguish between them. High resolution studies are often necessary to separate effects of excitation and radiative transfer from those of chemistry - one example is absorption and effects of stimulated emission in the ULIRG Arp220. The nuclear activity in luminous galaxies often drives outflows and winds and in some cases molecular gas is being entrained in the outflows. Sometimes the molecular gas is carrying the bulk of the momentum. We can study the structure and physical conditions of the molecular gas to constrain the mass outflow rates and the evolution and nature of the driving source and two examples are discussed here: NGC1377 and Mrk231.

Keywords

galaxies: evolution — galaxies: ISM — galaxies:active — radio lines: ISM — ISM: molecules — ISM:abundances — astrochemistry
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 9 , Symposium S303: The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus , October 2013 , pp. 15 - 28
Copyright
Copyright © International Astronomical Union 2014 

References

Aalto, S., Beswick, R., & Jütte, E. 2010, A&A 522, A59Google Scholar
Aalto, S., Booth, R. S., Black, J. H., & Johansson, L. E. B. 1995, A&A 300, 369Google Scholar
Aalto, S., Costagliola, F., van der Tak, F., & Meijerink, R. 2011, A&A 527, A69Google Scholar
Aalto, S., Garcia-Burillo, S., Muller, S., et al. 2012a, A&A 537, A44Google Scholar
Aalto, S., Monje, R., & Martín, S. 2007a, A&A 475, 479Google Scholar
Aalto, S., Muller, S., Sakamoto, K., et al. 2012b, A&A 546, A68Google Scholar
Aalto, S., Polatidis, A. G., Hüttemeister, S., & Curran, S. J. 2002, A&A 381, 783Google Scholar
Aalto, S., Radford, S. J. E., Scoville, N. Z., & Sargent, A. I. 1997, ApJ Lett. 475, L107Google Scholar
Aalto, S., Spaans, M., Wiedner, M. C., & Hüttemeister, S. 2007b, A&A 464, 193Google Scholar
Aalto, S., Wilner, D., Spaans, M., et al. 2009, A&A 493, 481Google Scholar
Aladro, R., Martín, S., Martín-Pintado, J., et al. 2011, A&A 535, A84Google Scholar
Aladro, R., Viti, S., Bayet, E., et al. 2013 A&A 549A, 39Google Scholar
Alatalo, K., Blitz, L., Young, L. M., et al. 2011, ApJ 735, 88Google Scholar
Ao, Y., Henkel, C., Menten, K. M., et al. 2013, A&A 550, A135Google Scholar
Baan, W. A. 2007, Nea Astr. Revs 51, 149Google Scholar
Baan, W. A., Loenen, A. F., & Spaans, M. 2010, A&A 516, A40Google Scholar
Bayet, E., Williams, D. A., Hartquist, T. W., & Viti, S. 2011, MNRAS 414, 1583Google Scholar
Chung, A., Yun, M. S., Naraynan, G., Heyer, M., & Erickson, N.R. 2011, ApJ Lett. 732, L15+Google Scholar
Cicone, C., Feruglio, C., Maiolino, R., et al. 2012, A&A 543, A99Google Scholar
Cicone, C., Maiolino, R., Sturm, E., et al. 2014 A&A 562A, 21Google Scholar
Costagliola, F. & Aalto, S. 2010, A&A 515, A71Google Scholar
Costagliola, F., Aalto, S., Rodriguez, M. I., et al. 2011, A&A 528, A30Google Scholar
Costagliola, F., Aalto, S., Sakamoto, K., et al. 2013, A&A 556, A66Google Scholar
Curran, S. J., Polatidis, A. G., Aalto, S., & Booth, R.S. 2001, A&A 373, 459Google Scholar
Evans, A. S., Becklin, E. E., Scoville, N. Z., et al. 2003, AJ 125, 2341Google Scholar
Feruglio, C., Maiolino, R., Piconcelli, E., et al. 2010, A&A 518, L155+Google Scholar
Fischer, J., Sturm, E., González-Alfonso, E., et al. 2010, A&A 518, L41Google Scholar
Gao, Y. & Solomon, P. M. 2004, ApJS 152, 63Google Scholar
García-Burillo, S., Martín-Pintado, J., Fuente, A., & Neri, R. 2000, A&A 355, 499Google Scholar
García-Burillo, S., Martín-Pintado, J., Fuente, A., & Neri, R. 2001, ApJ Lett. 563, L27Google Scholar
García-Burillo, S., Usero, A., Fuente, A., et al. 2010, A&A 519, A2Google Scholar
González-Alfonso, E., Fischer, J., Isaak, K., et al. 2010, A&A 518, L43Google Scholar
Graciá-Carpio, J., García-Burillo, S., Planesas, P., & Colina, L. 2006, ApJ Lett. 640, L135CrossRefGoogle Scholar
Greve, A., Neininger, N., Tarchi, A., & Sievers, A. 2000, A&A 364, 409Google Scholar
Guillet, V., Jones, A. P. & Pineau Des Forêts, G. 2009, A&A 497, 145Google Scholar
Harada, N., Herbst, E., & Wakelam, V. 2010, ApJ 721, 1570Google Scholar
Helfer, T.T. & Blitz, L. 1993, ApJ 419, 86Google Scholar
Hirota, A., Kuno, N., Sato, N., et al. 2010, PASJ 62, 1261Google Scholar
Hollenbach, D.J. & Tielens, A.G.G.M. 1997, ARAA 35, 179Google Scholar
Imanishi, M. & Nakanishi, K. 2013, AJ 146, 91Google Scholar
Imanishi, M., Nakanishi, K., Tamura, Y., Oi, N., & Kohno, K. 2007, AJ 134, 2366Google Scholar
Imanishi, M., Nakanishi, K., Tamura, Y., & Peng, C. 2009, AJ 137, 3581Google Scholar
Kazandjian, M. V., Meijerink, R., Pelupessy, I., Israel, F. P., & Spaans, M. 2012, A&A 542, A65Google Scholar
Kohno, K. 2003, in Astronomical Society of the Pacific Conference Series, Vol. 289, The Proceedings of the IAU 8th Asian-Pacific Regional Meeting, Volume 1, ed. Ikeuchi, S., Hearnshaw, J., & Hanawa, T., 349–352Google Scholar
König, S., Aalto, S., Muller, S., Beswick, R. J., & Gallagher, J. S. 2013, A&A 553, A72Google Scholar
Krips, M., Neri, R., García-Burillo, S., et al. 2008, ApJ 677, 262Google Scholar
Lepp, S. & Dalgarno, A. 1996, A&A 306, L21Google Scholar
Lindberg, J. E., Aalto, S., Costagliola, F., et al. 2011, A&A 527, A150Google Scholar
Maloney, P. R., Hollenbach, D. J., & Tielens, A. G. G. M. 1996, ApJ 466, 561Google Scholar
Mangum, J. G., Darling, J., Henkel, C., et al. 2013, ApJ 779, 33Google Scholar
Martin, C. L., Walsh, W. M., Xiao, K., et al. 2004, ApJS 150, 239Google Scholar
Martin, R. N. & Ho, P. T. P. 1986, ApJ Lett. 308, L7Google Scholar
Martín, S., Krips, M., Martín-Pintado, J., et al. 2011, A&A 527, A36Google Scholar
Martín, S., Mauersberger, R., Martín-Pintado, J., Henkel, C., & García-Burillo, S. 2006, ApJS 164, 450Google Scholar
Matsushita, S., Muller, S., & Lim, J. 2007, A&A 468, L49Google Scholar
Meier, D. S. & Turner, J. L. 2005, ApJ 618, 259Google Scholar
Meier, D. S. & Turner, J. L. 2012, ApJ 755, 104Google Scholar
Meier, D. S., Turner, J.L., & Hurt, R. L. 2000, ApJ 531, 200Google Scholar
Meijerink, R., Kristensen, L. E., Weiß, A., et al. 2013, ApJ Lett. 762, L16Google Scholar
Meijerink, R. & Spaans, M. 2005, A&A 436, 397Google Scholar
Meijerink, R., Spaans, M., Loenen, A. F., & van der Werf, P. P. 2011, A&A 525, A119Google Scholar
Mills, E. A. C., Güsten, R., Requena-Torres, M. A., & Morris, M. R. 2013, ApJ 779, 47Google Scholar
Mühle, S., Seaquist, E. R., & Henkel, C. 2007, ApJ 671, 1579Google Scholar
Muller, S., Beelen, A., Guélin, M., et al. 2011, A&A 535, A103Google Scholar
Nakai, N., Hayashi, M., Handa, T., et al. 1987, PASJ 39, 685Google Scholar
Nakajima, T., Takano, S., Kohno, K., & Inoue, H. 2011, ApJ Lett. 728, L38Google Scholar
Narayanan, D., Krumholz, M. R., Ostriker, E. C., & Hernquist, L. 2012, MNRAS 2537Google Scholar
Nesvadba, N. P. H., Polletta, M., Lehnert, M. D., et al. 2011, MNRAS 415, 2359Google Scholar
Nomura, H. & Millar, T. J. 2004, A&A 414, 409Google Scholar
Olsson, E., Aalto, S., Thomasson, M., & Beswick, R. 2010, A&A 513, A11Google Scholar
Paglione, T. A. D., Wall, W. F., Young, J. S., et al. 2001, ApJS 135, 183Google Scholar
Papadopoulos, P. P., van der Werf, P., Isaak, K., & Xilouris, E. M. 2010, ApJ 715, 775Google Scholar
Polletta, M., Nesvadba, N. P. H., Neri, R., et al. 2011, A&A 533, A20Google Scholar
Rickert, M., Momjian, E., Sarma, A. & AO Arp 220 Team. 2011, in Bulletin of the American Astronomical Society, Vol.43, American Astronomical Society Meeting Abstracts #217, #332.01Google Scholar
Rodriguez-Franco, A., Martin-Pintado, J., & Fuente, A. 1998, A&A 329, 1097Google Scholar
Sakamoto, K. 2012, ArXiv e-printsGoogle Scholar
Sakamoto, K., Aalto, S., Costagliola, F., et al. 2013, ApJ 764, 42Google Scholar
Sakamoto, K., Aalto, S., Evans, A. S., Wiedner, M. C., & Wilner, D.J. 2010, ApJ Lett. 725, L228Google Scholar
Sakamoto, K., Aalto, S., Wilner, D. J., et al. 2009, ApJ Lett. 700, L104Google Scholar
Sakamoto, K., Ho, P. T. P., & Peck, A. B. 2006, ApJ 644, 862Google Scholar
Schilke, P., Walmsley, C. M., Pineau Des Forets, G., et al. 1992, A&A 256, 595Google Scholar
Spoon, H. W. W., Marshall, J. A., Houck, J. R., et al. 2007, ApJ Lett. 654, L49CrossRefGoogle Scholar
Sturm, E., González-Alfonso, E., Veilleux, S., et al. 2011, ApJ Lett. 733, L16Google Scholar
Suchkov, A., Allen, R. J., & Heckman, T. M. 1993, ApJ 413, 542Google Scholar
Tafalla, M., Santiago-García, J., Hacar, A., & Bachiller, R. 2010, A&A 522, A91Google Scholar
Tosaki, T., Hasegawa, T., Shioya, Y., Kuno, N., & Matsushita, S. 2002, PASJ 54, 209Google Scholar
Tsai, A.-L., Matsushita, S., Nakanishi, K., et al. 2009, PASJ 61, 237Google Scholar
Usero, A., García-Burillo, S., Martín-Pintado, J., Fuente, A., & Neri, R. 2007, Nea Astr. Revs 51, 75Google Scholar
van der Tak, F. F. S., Aalto, S., & Meijerink, R. 2008, A&A 477, L5Google Scholar
van der Werf, P. P., Isaak, K.G., Meijerink, R., et al. 2010, A&A 518, L42Google Scholar
Viti, S. 2005, in IAU Symposium, Vol. 231, Astrochemistry: Recent Successes and Current Challenges, ed. Lis, D.C., Blake, G.A., & Herbst, E., 67–76Google Scholar
Viti, S., Jimenez-Serra, I., Yates, J.A., et al. 2011, ApJ Lett. 740, L3Google Scholar
Wada, K. & Tomisaka, K. 2005, ApJ 619, 93Google Scholar
Walter, F., Weiss, A., & Scoville, N. 2002, ApJ Lett. 580, L21Google Scholar