Using Hydrogen Recombination Masers To Study Disk And Wind Kinematics In Mwc 349A
Creators: name: Emery, Deanna
Publisher: name: Zenodo
Year: 2017
Subjects: subject: http://astrothesaurus.org/uat/235
subject: http://astrothesaurus.org/uat/103
subject: http://astrothesaurus.org/uat/1608

description: The kinematics of circumstellar disks and disk winds are poorly understood due to the difficulty of producing well resolved observational data. The bright hydrogen recombination-line maser emission originating from the circumstellar disk of MWC 349A offers a unique opportunity to study the disk at milli-arcsecond precision. Using high angular resolution observations of the maser emission from MWC 349A carried out by the SMA, we were able to produce and analyze rotation curves for the H26α, H30α, and H31α transitions. We found that maser features originating from the disk follow Keplerian motion. Furthermore, the H31α masers in the disk appear to form in a narrow annulus at a fixed radius from the star, consistent with previous studies of the H30α and H26α masers. Based on analysis of the rotation curves for the three maser transitions, there appears to be an inverse relationship between the frequency of the maser emission and the radial extent to which the corresponding maser emission spans. This implies that maser transitions for lower quantum numbers occur in the inner and denser regions of the disk than the higher quantum transitions. Using the scaling relationship between quantum number and radius of emission for each maser transition, we derived the density distribution throughout the disk, which follows the relation n e ∼ R −4.9±0.6 . Finally, we found that a stellar mass of M = 10 ± 3 M ? was most consistent with the kinematices of the maser features originating from the Keplerian disk.
description: Astro 99
description: {"references": ["B\u00e1ez-Rubio, A., Mart\u00b4\u0131n-Pintado, J., Thum, C., Planesas, P. and Torres- Redondo, J. (2014), 'Origin of the ionized wind in MWC 349A', Astronomy and Astrophysics 571, L4.", "Chen, X., Arce, H. G., Zhang, Q., Launhardt, R. and Henning, T. (2016), 'Rotating Bullets from A Variable Protostar', The Astrophysical Journal 824, 72.", "Cohen, M., Bieging, J. H., Dreher, J. W. and Welch, W. J. (1985), 'The binary system MWC 349', The Astrophysical Journal 292, 249\u2013256.", "Cox, P., Martin-Pintado, J., Bachiller, R., Bronfman, L., Cernicharo, J., Nyman, L.-A. and Roelfsema, P. R. (1995), 'Millimeter recombination lines towards Eta Carinae', Astronomy and Astrophysics 295, L39\u2013L42.", "Elitzur, M. (1982), 'Physical characteristics of astronomical masers', Reviews of Modern Physics 54, 1225\u20131260.", "Elitzur, M., ed. (1992), Astronomical masers, Vol. 170 of Astrophysics and Space Science Library.", "Gordon, M. A. and Sorochenko, R. L. (2009), Radio Recombination Lines: Their Physics and Astronomical Applications, Vol. 282 of Astrophysics and Space Science Library.", "Gray, M. (2012), Maser Sources in Astrophysics.", "Gvaramadze, V. V. and Menten, K. M. (2012), 'Discovery of a parsec-scale bipolar nebula around MWC 349A', Astronomy and Astrophysics 541, A7.", "Haykin, S. and Liu, K. J. R. (2009), Handbook on Array Processing and Sensor Networks.", "Jackson, N. (2008), Principles of Interferometry, in F. Bacciotti, L. Testi and E. Whelan, eds, 'Jets from Young Stars II', Vol. 742 of Lecture Notes in Physics, Berlin Springer Verlag, p. 193.", "Jim\u00b4 enez-Serra, I., B\u00b4 aez-Rubio, A., Rivilla, V. M., Mart\u00b4\u0131n-Pintado, J., Zhang, Q., Dierickx, M. and Patel, N. (2013), 'A New Radio Recombination Line Maser Object toward the MonR2 H II Region', The Astrophysical Journal, Letters 764, L4.", "Jim\u00b4 enez-Serra, I., Mart\u00b4\u0131n-Pintado, J., B\u00e1ez-Rubio, A., Patel, N. and Thum, C. (2011), 'Extremely Broad Radio Recombination Maser Lines Toward the High-velocity Ionized Jet in Cepheus A HW2', The Astrophysical Jour- nal, Letters 732, L27.", "Keto, E. and Zhang, Q. (2010), 'The standard model of star formation applied to massive stars: accretion discs and envelopes in molecular lines', Monthly Notices of the RAS 406, 102\u2013111.", "Martin-Pintado, J., Bachiller, R., Thum, C. and Walmsley, M. (1989), 'A radio recombination line maser in MWC349', Astronomy and Astrophysics 215, L13\u2013L16.", "Martin-Pintado, J., Gaume, R., Bachiller, R., Johnston, K. and Planesas, P. (1993), 'Simulated Ratio Recombination Line Emission at 1.3 Centimeters toward MWC 349', The Astrophysical Journal, Letters 418, L79.", "Mart\u00b4\u0131n-Pintado, J., Thum, C., Planesas, P. and B\u00b4 aez-Rubio, A. (2011), 'Disk and wind kinematics in MWC 349 A', Astronomy and Astrophysics 530, L15.", "Planesas, P., Martin-Pintado, J. and Serabyn, E. (1992), 'Positions of the radio recombination line masers in MWC 349', The Astrophysical Journal, Letters 386, L23\u2013L26.", "Ponomarev, V. O., Smith, H. A. and Strelnitski, V. S. (1994), 'Modeling of the hydrogen maser disk in MWC 349', The Astrophysical Journal 424, 976\u2013982.", "Pringle, J. E. (1981), 'Accretion discs in astrophysics', Annual Review of Astronomy and Astrophysics 19, 137\u2013162.", "Qi, C. (2015), The MIR Cookbook.", "Ryle, M., Smith, F. G. and Elsmore, B. (1950), 'A preliminary survey of the radio stars in the Northern Hemisphere', Monthly Notices of the RAS 110, 508.", "Storey, P. J. and Hummer, D. G. (1995), 'Recombination line intensities for hydrogenic ions-IV. Total recombination coefficients and machine-readable tables for Z=1 to 8', Monthly Notices of the RAS 272, 41\u201348.", "Strelnitski, V. S., Ponomarev, V. O. and Smith, H. A. (1996), 'Hydrogen Masers. I. Theory and Prospects', The Astrophysical Journal 470, 1118.", "Strelnitski, V. S., Smith, H. A. and Ponomarev, V. O. (1996), 'Hydrogen Masers. II. MWC 349A', The Astrophysical Journal 470, 1134.", "Tafoya, D., G\u00f3mez, Y. and Rodr\u00b4\u0131guez, L. F. (2004), 'Imaging MWC 349 from 7 Millimeters to 90 Centimeters', The Astrophysical Journal 610, 827\u2013834.", "Taylor, G. B., Carilli, C. L. and Perley, R. A., eds (1999), Synthesis Imaging in Radio Astronomy II, Vol. 180 of Astronomical Society of the Pacific Conference Series.", "Thompson, A. R., Moran, J. M. and Swenson, Jr., G. W. (2017), Interfer- ometry and Synthesis in Radio Astronomy, 3rd Edition.", "Thum, C., Martin-Pintado, J. and Bachiller, R. (1992), 'Monitoring of the recombination line maser in MWC349', Astronomy and Astrophysics 256, 507\u2013518.", "Thum, C., Matthews, H. E., Harris, A. I., Tacconi, L. J., Schuster, K. F. and Martin-Pintado, J. (1994), 'Detection of H21\u03b1 maser emission at 662 GHz in MWC 349', Astronomy and Astrophysics 288.", "Thum, C., Strelnitski, V. S., Martin-Pintado, J., Matthews, H. E. and Smith, H. A. (1995), 'Hydrogen recombination \u03b2-lines in MWC 349.', Astronomy and Astrophysics 300, 843.", "Weintroub, J., Moran, J. M., Wilner, D. J., Young, K., Rao, R. and Shin- naga, H. (2008), 'Submillimeter Array Imaging of the Maser Emission from the H30\u03b1 Radio Recombination Line in MWC 349A', The Astrophysical Journal 677, 1140\u20131150.", "Zhang, Q., Claus, B., Watson, L. and Moran, J. (2017), 'Angular Momentum in Disk Wind Revealed in the Young Star MWC349A', ArXiv e-prints .", "Zhao, J. (2012), Basic Information on uvfit."]}