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Full-Text Articles in Physical Sciences and Mathematics
Dust Stratification In Young Circumstellar Disks, Terrence Rettig, Sean D. Brittain, Theodore Simon, Erika Gibb, Dinshaw S. Balsara, David A. Tilley, Craig Kulesa
Dust Stratification In Young Circumstellar Disks, Terrence Rettig, Sean D. Brittain, Theodore Simon, Erika Gibb, Dinshaw S. Balsara, David A. Tilley, Craig Kulesa
Publications
We present high-resolution infrared spectra of four YSOs (T Tau N, T Tau S, RNO 91, and HL Tau). The spectra exhibit narrow absorption lines of 12CO, 13CO, and C18O, as well as broad emission lines of gas-phase 12CO. The narrow absorption lines of CO are shown to originate from the colder circumstellar gas. We find that the line-of-sight gas column densities resulting from the CO absorption lines are much higher than expected for the measured extinction for each source and suggest the gas/dust ratio is measuring the dust settling and/or grain coagulation in these extended disks. We provide a …
Co Line Emission And Absorption From The Hl Tauri Disk-Where Is All The Dust?, Sean D. Brittain, Terrence W. Rettig, Theodore Simon, Craig Kulesa
Co Line Emission And Absorption From The Hl Tauri Disk-Where Is All The Dust?, Sean D. Brittain, Terrence W. Rettig, Theodore Simon, Craig Kulesa
Publications
We present high-resolution infrared spectra of HL Tau, a heavily embedded young star. The spectra exhibit broad emission lines of 12CO gas-phase molecules, as well as narrow absorption lines of 12CO, 13CO, and C18O. The broad emission lines of vibrationally excited 12CO are dominated by the hot (T ~ 1500 K) inner disk. The narrow absorption lines of CO are found to originate from the circumstellar gas at a temperature of ~100 K. The 12CO column density for this cooler material [(7.5 ± 0.2) × 1018 cm-2] indicates a large column of absorbing gas along the line of sight. In …
Discovery Of Co Gas In The Inner Disk Of Tw Hydrae, Terrence W. Rettig, Joe Haywood, Theodore Simon, Sean D. Brittain, Erika Gibb
Discovery Of Co Gas In The Inner Disk Of Tw Hydrae, Terrence W. Rettig, Joe Haywood, Theodore Simon, Sean D. Brittain, Erika Gibb
Publications
We report the detection of rovibrationally excited CO emission from the inner disk of the classical T Tauri star (cTTS) TW Hya. We observe ~6 × 1021 g of CO gas with a rotational temperature of 430 ± 40 K. The linearity of the excitation plot suggests that the CO is optically thin. Atypical for cTTSs, hot CO was not detected, implying that TW Hya has cleared its inner disk region out to a radial distance of ~0.5 AU. We discuss implications for the structure of the disk as it relates to replenishment and planet formation.