Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-25T05:53:16.115Z Has data issue: false hasContentIssue false

Measuring the physical conditions of accreting gas in T Tauri systems

Published online by Cambridge University Press:  01 May 2007

Jeffrey S. Bary
Affiliation:
Department of Astronomy, University of Virginia, Charlottesville, VA 22902, USA email: [email protected], [email protected]
Sean P. Matt
Affiliation:
Department of Astronomy, University of Virginia, Charlottesville, VA 22902, USA email: [email protected], [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Hydrogen emission lines observed from T Tauri stars (TTS) are associated with the accretion/outflow of gas in these young star forming systems. Magnetospheric accretion models have been moderately successful at reproducing the shapes of several Hi emission line profiles, suggesting that the emission arises in the accretion funnels. Despite considerable effort to model and observe these emission features, the physical conditions of the gas confined to the funnel flows remain poorly constrained by observation. We conducted a mutli-epoch near-infrared spectroscopic survey of 16 actively accreting classical TTS in the Taurus-Auriga star forming region. We present an analysis of these simultaneously acquired line flux ratios of many Paschen and Brackett series emission lines, in which we compare the observed ratios to those predicted by the Case B approximation of hydrogen recombination line theory. We find that the line flux ratios for the Paschen and Brackett decrements as well as a comparison between Brγ and Paschen transitions agree well with the Case B models with T < 5000 K and ne ≈ 1010 cm−3.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2007

References

Alencar, S. H. P., & Basri, G. 2000, AJ, 119, 1881CrossRefGoogle Scholar
Baker, J. G., Menzel, D. H., Aller, L. H. 1938, ApJ, 88, 422CrossRefGoogle Scholar
Basri, G., & Batalha, C. 1990, ApJ, 363, 654CrossRefGoogle Scholar
Cushing, M. C., Vacca, W. D., Rayner, J. T. 2004, PASP, 116, 362CrossRefGoogle Scholar
Folha, D. F. M., & Emerson, J. P. 2001, A&A, 365, 90Google Scholar
Ghosh, P., & Lamb, F. K. 1979, ApJ, 234, 296CrossRefGoogle Scholar
Hartmann, L., Hewett, R., Calvet, N. 1994, ApJ, 426, 669CrossRefGoogle Scholar
Johns, C. M., & Basri, G. 1995, AJ, 109, 2800CrossRefGoogle Scholar
Königl, A. 1991, ApJ, 370, L39CrossRefGoogle Scholar
Martin, S. C. 1996, ApJ, 470, 537CrossRefGoogle Scholar
Muzerolle, J., Calvet, N., Hartmann, L. 1998a, ApJ, 492, 743CrossRefGoogle Scholar
Muzerolle, J., Calvet, N., Hartmann, L. 2001, ApJ, 550, 944CrossRefGoogle Scholar
Muzerolle, J., Hartmann, L., Calvet, N. 1998b, AJ, 116, 455CrossRefGoogle Scholar
Shu, F., Najita, J., Ostriker, E., Wilkin, F., Ruden, S., Lizano, S. 1994, ApJ, 429, 781CrossRefGoogle Scholar
Skrutskie, M. F., Meyer, M. R., Whalen, D., Hamilton, C. 1996, AJ, 112, 2168CrossRefGoogle Scholar
Storey, P. J., & Hummer, D. G. 1995, MNRAS, 272, 41CrossRefGoogle Scholar