The Distribution of 870 µm Continuum, CO(3-2) and HCO+(4-3) Molecules Around TW HYA, Based on Science Verification Data from ATACAMA Large Millimeter/Submillimeter Array (ALMA), Band 7 Data

Abdulrahman Malawi, Dalal Al Ghamdi


The study of the chemistry of protoplanetary disks has broad implication for our understanding of planet compositions and the availability of the conditions necessary for life. The science verification data from the Atacama Large Millimeter/submillimeter Array (ALMA) band 7 (345 GHz) observation of TW Hya, a classical T Tauri star, at lines of HCO+ (4-3) and CO (3-2) with a 1.5" angular and 0.2km/s spectral resolution was used for this study. CASA, the common astronomy software applications package was used for the data reduction, including, calibrating, cleaning and imaging of both spectral line and the continuum. The final dust, CO(3-2) and HCO+(4-3) images of the disk and the corresponding models are presented and discussed.


Circumstellar; individual(TWHydra); protoplanetary disks; submillimeter; stars; molecular processes.

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de La Reza, R., Torres, C. A., Quast, G., Castilho, B. V. & Vieira, G. L. Discovery of new isolated T Tauri stars. The Astrophysical Journal 343, L61-L64 (1989).

Webb, R. et al. Discovery of Seven T Tauri Stars and a Brown Dwarf Candidatein the Nearby TW Hydrae Association. The Astrophysical Journal Letters 512, L63 (1999).

Sterzik, M. F., Alcalá, J. M., Covino, E. & Petr, M. G. New T Tauri stars in the vicinity of TW Hydrae. Astronomy and Astrophysics 346, L41-L44 (1999).

Zuckerman, B., Song, I. & Webb, R. Tucana Association. The Astrophysical Journal 559, 388 (2001).

Song, I., Zuckerman, B. & Bessell, M. New Members of the TW Hydrae Association, β Pictoris Moving Group, and Tucana/Horologium Association. The Astrophysical Journal 599, 342 (2003).

Van Leeuwen, F. Validation of the new Hipparcos reduction. Astronomy & Astrophysics 474, 653-664 (2007).

Alencar, S. H. & Batalha, C. Variability of southern T Tauri stars. II. The spectral variability of the classical T Tauri star TW Hydrae. The Astrophysical Journal 571, 378 (2002).

Rosenfeld, K. A., Andrews, S. M., Wilner, D. J. & Stempels, H. A disk-based dynamical mass estimate for the young binary V4046 Sgr. The Astrophysical Journal 759, 119 (2012).

Thi, W.-F., Van Zadelhoff, G.-J. & van Dishoeck, E. F. Organic molecules in protoplanetary disks around T Tauri and Herbig Ae stars. Astronomy & Astrophysics 425, 955-972 (2004).

Qi, C. et al. Imaging the disk around TW Hydrae with the submillimeter array. The Astrophysical Journal Letters 616, L11 (2004).

Qi, C. et al. CO J= 6-5 observations of TW Hydrae with the Submillimeter Array. The Astrophysical Journal Letters 636, L157 (2006).

Qi, C. et al. Resolving the CO snow line in the disk around HD 163296. The Astrophysical Journal 740, 84 (2011).

Rodriguez, D. R., Kastner, J. H., Wilner, D. & Qi, C. Imaging the Molecular Disk Orbiting the Twin Young Suns of V4046 Sgr. The Astrophysical Journal 720, 1684 (2010).

Andrews, S. M. et al. Ringed substructure and a gap at 1 au in the nearest protoplanetary disk. The Astrophysical Journal Letters 820, L40 (2016).

Rosenfeld, K. A., Andrews, S. M., Wilner, D. J., Kastner, J. & McClure, M. The structure of the evolved circumbinary disk around V4046 Sgr. The Astrophysical Journal 775, 136 (2013).

Menu, J. et al. On the structure of the transition disk around TW Hydrae. Astronomy & Astrophysics 564, A93 (2014).

Aikawa, Y., Furuya, K., Nomura, H. & Qi, C. Analytical Formulae of Molecular Ion Abundances and the N2H+ Ring in Protoplanetary Disks. The Astrophysical Journal 807, 120 (2015).

Rapson, V. A., Kastner, J. H., Millar-Blanchaer, M. A. & Dong, R. Peering into the Giant-planet-forming Region of the TW Hydrae Disk with the Gemini Planet Imager. The Astrophysical Journal Letters 815, L26 (2015).

Debes, J. H., Jang-Condell, H. & Schneider, G. The inner structure of the TW Hya Disk as revealed in scattered light. The Astrophysical Journal Letters 819, L1 (2016).

Wilner, D. J., D'Alessio, P., Calvet, N., Claussen, M. & Hartmann, L. Toward planetesimals in the disk around TW Hydrae: 3.5 centimeter dust emission. The Astrophysical Journal Letters 626, L109 (2005).

Testi, L., Natta, A., Shepherd, D. & Wilner, D. Large grains in the disk of CQ Tau. Astronomy & Astrophysics 403, 323-328 (2003).

Calvet, N. et al. Evidence for a developing gap in a 10 Myr old protoplanetary disk. The Astrophysical Journal 568, 1008 (2002).

Hughes, A. et al. An inner hole in the disk around TW Hydrae resolved in 7 mm dust emission. The Astrophysical Journal 664, 536 (2007).

Debes, J. H., Jang-Condell, H., Weinberger, A. J., Roberge, A. & Schneider, G. The 0.5-2.22 micrometer Scattered Light Spectrum of the Disk around TW Hya: Detection of a Partially Filled Disk Gap at 80 AU. (2013).

Akiyama, E. et al. Discovery of a disk gap candidate at 20 AU in TW Hydrae. The Astrophysical Journal Letters 802, L17 (2015).

Wilner, D., Ho, P., Kastner, J. & Rodríguez, L. VLA imaging of the disk surrounding the nearby young star TW Hydrae. The Astrophysical Journal Letters 534, L101 (2000).

Hughes, A. M., Wilner, D. J., Andrews, S. M., Qi, C. & Hogerheijde, M. R. Empirical constraints on turbulence in protoplanetary accretion disks. The Astrophysical Journal 727, 85 (2011).

Ruane, G. et al. Deep imaging search for planets forming in the TW Hya protoplanetary disk with the Keck/NIRC2 vortex coronagraph. The Astronomical Journal 154, 73 (2017).

Andrews, S. M. et al. The TW Hya disk AT 870 μm: Comparison of co and dust radial structures. The Astrophysical Journal 744, 162 (2011).

Rodriguez, D. R. et al. An ALMA survey for disks orbiting low-mass stars in the TW Hya Association. Astronomy & Astrophysics 582, L5 (2015).

Lada, C. J. in Symposium-International Astronomical Union. 1-18 (Cambridge University Press).

Robitaille, T. P. HYPERION: an open-source parallelized three-dimensional dust continuum radiative transfer code. Astronomy & Astrophysics 536, A79 (2011).

Draine, B. T. Interstellar dust grains. Annual Review of Astronomy and Astrophysics 41, 241-289 (2003).

Cleeves, L. I., Bergin, E. A., Qi, C., Adams, F. C. & Öberg, K. I. Constraining the X-ray and cosmic-ray ionization chemistry of the TW Hya protoplanetary disk: evidence for a sub-interstellar cosmic-ray rate. The Astrophysical Journal 799, 204 (2015).

Huang, J. et al. CO and dust properties in the TW Hya disk from high-resolution ALMA observations. The Astrophysical Journal 852, 122 (2018).

Nomura, H. et al. ALMA observations of a gap and a ring in the protoplanetary disk around TW Hya. The Astrophysical Journal Letters 819, L7 (2016).

Bergin, E. A. et al. An old disk still capable of forming a planetary system. Nature 493, 644 (2013).

Favre, C., Cleeves, L. I., Bergin, E. A., Qi, C. & Blake, G. A. A Significantly Low CO Abundance Toward the TW Hya Protoplanetary Disk: A Path to Active Carbon Chemistry? The Astrophysical Journal Letters 776, L38 (2013).

Williams, J. P. & Best, W. M. A parametric modeling approach to measuring the gas masses of circumstellar disks. The Astrophysical Journal 788, 59 (2014).


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