Characterizing the stellar photospheres and near-infrared excesses in accreting T tauri systems

M. K. McClure, N. Calvet, C. Espaillat, L. Hartmann, J. Hernández, L. Ingleby, K. L. Luhman, P. D'Alessio, B. Sargent

Research output: Contribution to journalArticle

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Abstract

Using NASA Infrared Telescope Facility SpeX data from 0.8 to 4.5 μm, we determine self-consistently the stellar properties and excess emission above the photosphere for a sample of classical T Tauri stars (CTTS) in the Taurus molecular cloud with varying degrees of accretion. This process uses a combination of techniques from the recent literature as well as observations of weak-line T Tauri stars to account for the differences in surface gravity and chromospheric activity between the T Tauri stars and dwarfs, which are typically used as photospheric templates for CTTS. Our improved veiling and extinction estimates for our targets allow us to extract flux-calibrated spectra of the excess in the near-infrared. We find that we are able to produce an acceptable parametric fit to the near-infrared excesses using a combination of up to three blackbodies. In half of our sample, two blackbodies at temperatures of 8000 K and 1600 K suffice. These temperatures and the corresponding solid angles are consistent with emission from the accretion shock on the stellar surface and the inner dust sublimation rim of the disk, respectively. In contrast, the other half requires three blackbodies at 8000, 1800, and 800 K, to describe the excess. We interpret the combined two cooler blackbodies as the dust sublimation wall with either a contribution from the disk surface beyond the wall or curvature of the wall itself, neither of which should have single-temperature blackbody emission. In these fits, we find no evidence of a contribution from optically thick gas inside the inner dust rim.

Original languageEnglish (US)
Article number73
JournalAstrophysical Journal
Volume769
Issue number1
DOIs
StatePublished - May 20 2013

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T Tauri stars
photosphere
near infrared
sublimation
dust
rims
accretion
temperature
infrared telescopes
curvature
extinction
molecular clouds
coolers
gravity
templates
shock
gravitation
gas
estimates
gases

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

McClure, M. K., Calvet, N., Espaillat, C., Hartmann, L., Hernández, J., Ingleby, L., ... Sargent, B. (2013). Characterizing the stellar photospheres and near-infrared excesses in accreting T tauri systems. Astrophysical Journal, 769(1), [73]. https://doi.org/10.1088/0004-637X/769/1/73
McClure, M. K. ; Calvet, N. ; Espaillat, C. ; Hartmann, L. ; Hernández, J. ; Ingleby, L. ; Luhman, K. L. ; D'Alessio, P. ; Sargent, B. / Characterizing the stellar photospheres and near-infrared excesses in accreting T tauri systems. In: Astrophysical Journal. 2013 ; Vol. 769, No. 1.
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McClure, MK, Calvet, N, Espaillat, C, Hartmann, L, Hernández, J, Ingleby, L, Luhman, KL, D'Alessio, P & Sargent, B 2013, 'Characterizing the stellar photospheres and near-infrared excesses in accreting T tauri systems', Astrophysical Journal, vol. 769, no. 1, 73. https://doi.org/10.1088/0004-637X/769/1/73

Characterizing the stellar photospheres and near-infrared excesses in accreting T tauri systems. / McClure, M. K.; Calvet, N.; Espaillat, C.; Hartmann, L.; Hernández, J.; Ingleby, L.; Luhman, K. L.; D'Alessio, P.; Sargent, B.

In: Astrophysical Journal, Vol. 769, No. 1, 73, 20.05.2013.

Research output: Contribution to journalArticle

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AU - Calvet, N.

AU - Espaillat, C.

AU - Hartmann, L.

AU - Hernández, J.

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AU - D'Alessio, P.

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N2 - Using NASA Infrared Telescope Facility SpeX data from 0.8 to 4.5 μm, we determine self-consistently the stellar properties and excess emission above the photosphere for a sample of classical T Tauri stars (CTTS) in the Taurus molecular cloud with varying degrees of accretion. This process uses a combination of techniques from the recent literature as well as observations of weak-line T Tauri stars to account for the differences in surface gravity and chromospheric activity between the T Tauri stars and dwarfs, which are typically used as photospheric templates for CTTS. Our improved veiling and extinction estimates for our targets allow us to extract flux-calibrated spectra of the excess in the near-infrared. We find that we are able to produce an acceptable parametric fit to the near-infrared excesses using a combination of up to three blackbodies. In half of our sample, two blackbodies at temperatures of 8000 K and 1600 K suffice. These temperatures and the corresponding solid angles are consistent with emission from the accretion shock on the stellar surface and the inner dust sublimation rim of the disk, respectively. In contrast, the other half requires three blackbodies at 8000, 1800, and 800 K, to describe the excess. We interpret the combined two cooler blackbodies as the dust sublimation wall with either a contribution from the disk surface beyond the wall or curvature of the wall itself, neither of which should have single-temperature blackbody emission. In these fits, we find no evidence of a contribution from optically thick gas inside the inner dust rim.

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McClure MK, Calvet N, Espaillat C, Hartmann L, Hernández J, Ingleby L et al. Characterizing the stellar photospheres and near-infrared excesses in accreting T tauri systems. Astrophysical Journal. 2013 May 20;769(1). 73. https://doi.org/10.1088/0004-637X/769/1/73