Physical Sciences and Mathematics | Open Access Articles

An Exo-Kuiper Belt With An Extended Halo Around Hd 191089 In Scattered Light, Bin Ren, Élodie Choquet, Marshall D. Perrin, Gaspard Duchěne, John H. Debes, Laurent Pueyo, Malena Rice, Christine Chen, Glenn Schneider, Thomas M. Esposito, Charles A. Poteet, Jason J. Wang, S. Mark Ammons, Megan Ansdell, Pauline Arriaga, Vanessa P. Bailey, Travis Barman, Juan Sebastián Bruzzone, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Robert J. De Rosa, Rene Doyon, Michael P. Fitzgerald, Katherine B. Follette, Stephen J. Goodsell, Benjamin L. Gerard, James R. Graham, Alexandra Z. Greenbaum, J. Brendan Hagan, Pascale Hibon, Dean C. Hines, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ∼ 25 au, centered at ∼46 au) and a halo extending to ∼640 au. We find that the halo is significantly bluer than the ring, consistent with the scenario that the ring serves as the "birth ring" for the smaller dust in the halo. We measure the scattering phase functions in the 30°-150° scattering-angle range and find that the halo dust is more forward- and backward-scattering …

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Kinematic Links And The Coevolution Of Mhd Winds, Jets, And Inner Disks From A High-Resolution Optical [Oi] Survey, Andrea Banzatti, Ilaria Pascucci, Suzan Edwards, Min Fang, Uma Gorti, Mario Flock

Astronomy: Faculty Publications

We present a survey of optical [O I] emission at 6300 Å toward 65 T Tauri stars at the spectral resolution of ∼7 km s−1 . Past work identified a highly blueshifted velocity component (HVC) tracing microjets and a less blueshifted low-velocity component (LVC) attributed to winds. We focus here on the LVC kinematics to investigate links between winds, jets, accretion, and disk dispersal. We track the behavior of four types of LVC components: a broad and a narrow component (“BC” and “NC,” respectively) in LVCs that are decomposed into two Gaussians which typically have an HVC, and single-Gaussian LVC …

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A New Look At T Tauri Star Forbidden Lines: Mhd-Driven Winds From The Inner Disk, Min Fang, Ilaria Pascucci, Suzan Edwards, Uma Gorti, Andrea Banzatti, Mario Flock, Patrick Hartigan, Gregory J. Herczeg, Andrea K. Dupree

Astronomy: Faculty Publications

Magnetohydrodynamic (MHD) and photoevaporative winds are thought to play an important role in the evolution and dispersal of planet-forming disks. We report the first high-resolution (∆v ∼ 6 km s−1 ) analysis of [S II] λ4068, [O I] λ5577, and [O I] λ6300 lines from a sample of 48 T Tauri stars. Following Simon et al. (2016), we decompose them into three kinematic components: a high-velocity component (HVC) associated with jets, and a low-velocity narrow (LVC-NC) and broad (LVC-BC) components. We confirm previous findings that many LVCs are blueshifted by more than 1.5 km s−1 thus most likely trace a …

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The Taurus Boundary Of Stellar/Substellar (Tboss) Survey. Ii. Disk Masses From Alma Continuum Observations, Kimberly Ward-Duong, J. Patience, J. Bulger, G. Van Der Plas, F. Ménard, C. Pinte, A. P. Jackson, G. Bryden, N. J. Turner, P. Harvey, A. Hales, R. J. De Rosa

Astronomy: Faculty Publications

We report 885 μm ALMA continuum flux densities for 24 Taurus members spanning the stellar/substellar boundary with spectral types from M4 to M7.75. Of the 24 systems, 22 are detected at levels ranging from 1.0 to 55.7 mJy. The two nondetections are transition disks, though other transition disks in the sample are detected. Converting ALMA continuum measurements to masses using standard scaling laws and radiative transfer modeling yields dust mass estimates ranging from ∼0.3 to 20 M ⊕. The dust mass shows a declining trend with central object mass when combined with results from submillimeter surveys of more massive Taurus …

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Tracing Slow Winds From T Tauri Stars Via Low-Velocity Forbidden Line Emission, M. N. Simon, I. Pascucci, Suzan Edwards, W. Feng, U. Gorti, D. Hollenbach, E. Rigliaco, J. T. Keane

Astronomy: Faculty Publications

Using Keck/HIRES spectra (Δ v ∼ 7 km s−1) we analyze forbidden lines of [O I] 6300 Å, [O I] 5577 Å and [S II] 6731 Å from 33 T Tauri stars covering a range of disk evolutionary stages. After removing a high-velocity component (HVC) associated with microjets, we study the properties of the low-velocity component (LVC). The LVC can be attributed to slow disk winds that could be magnetically (magnetohydrodynamic) or thermally (photoevaporative) driven. Both of these winds play an important role in the evolution and dispersal of protoplanetary material. LVC emission is seen in all 30 stars with …

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Interpreting Near Infrared Hydrogen Line Ratios In T Tauri Stars, Suzan Edwards

Astronomy: Faculty Publications

In accreting young stars, one of the prominent spectral features in the near-infrared is the Paschen and Brackett series in emission. We examine hydrogen line ratios for 16 classical T Tauri stars from SpeX spectra and assess the trends with veiling and accretion. The observed line ratios are compared with two theoretical models for line formation: (1) Baker & Menzel’s Case B for radiative ionization and recombination and (2) a set of local line excitation calculations designed to replicate the conditions in T Tauri winds and magnetic accretion columns (KF). While the comparison between Case B and observed line ratios …

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Understanding The Origin Of The [Oi] Low-Velocity Component From T Tauri Stars, Elisabetta Rigliaco, Ilaria Pascucci, Uma Gorti, Suzan Edwards, D. Hollenbach

Astronomy: Faculty Publications

The formation time, masses, and location of planets are strongly impacted by the physical mechanisms that disperse protoplanetary disks and the timescale over which protoplanetary material is cleared out. Accretion of matter onto the central star, protostellar winds/jets, magnetic disk winds, and photoevaporative winds operate concurrently. Hence, disentangling their relative contribution to disk dispersal requires identifying diagnostics that trace different star–disk environments. Here, we analyze the low-velocity component (LVC) of the oxygen optical forbidden lines, which is found to be blueshifted by a few km s⁻¹ with respect to the stellar velocity. We find that the [O i] LVC …

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Hot Gas Lines In T Tauri Stars, David R. Ardila, Gregory J. Herczeg, Scott G. Gregory, Laura Ingleby, Kevin France, Alexander Brown, Suzan Edwards, Christopher Johns-Krull, Jeffrey L. Linsky, Hao Yang, Jeff A. Valenti, Hervé Abgrall, Richard D. Alexander, Edwin Bergin, Thomas Bethell, Joanna M. Brown, Nuria Calvet, Catherine Espaillat, Lynne A. Hillenbrand, Gaitee Hussain, Evelyne Roueff, Eric R. Schindhelm, Frederick M. Walter

Astronomy: Faculty Publications

For Classical T Tauri Stars (CTTSs), the resonance doublets of N v, Si iv, and Civ, as well as the He ii 1640 Å line, trace hot gas flows and act as diagnostics of the accretion process. In this paper we assemble a large high-resolution, high-sensitivity data set of these lines in CTTSs and Weak T Tauri Stars (WTTSs). The sample comprises 35 stars: 1 Herbig Ae star, 28 CTTSs, and 6 WTTSs. We find that the Civ, Si iv, and N v lines in CTTSs all have similar shapes. We decompose the Civ and He ii lines into broad …

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Characterizing The Iyj Excess Continuum Emission In T Tauri Stars, William J. Fischer, Suzan Edwards, Lynne A. Hillenbrand, John Kwan

Astronomy: Faculty Publications

We present the first characterization of the excess continuum emission of accreting T Tauri stars between optical and near-infrared wavelengths. With nearly simultaneous spectra from 0.48 to 2.4μm acquired with HIRES and NIRSPEC on Keck and SpeX on the Infrared Telescope Facility, we find significant excess continuum emission throughout this region, including the I, Y, and J bands, which are usually thought to diagnose primarily photospheric emission. The IYJ excess correlates with the excess in the V band, attributed to accretion shocks in the photosphere, and the excess in the K band, attributed to dust in the inner …

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Astronomy: Faculty Publications

Kinematic Links And The Coevolution Of Mhd Winds, Jets, And Inner Disks From A High-Resolution Optical [Oi] Survey, Andrea Banzatti, Ilaria Pascucci, Suzan Edwards, Min Fang, Uma Gorti, Mario Flock

Astronomy: Faculty Publications

A New Look At T Tauri Star Forbidden Lines: Mhd-Driven Winds From The Inner Disk, Min Fang, Ilaria Pascucci, Suzan Edwards, Uma Gorti, Andrea Banzatti, Mario Flock, Patrick Hartigan, Gregory J. Herczeg, Andrea K. Dupree

Astronomy: Faculty Publications

The Taurus Boundary Of Stellar/Substellar (Tboss) Survey. Ii. Disk Masses From Alma Continuum Observations, Kimberly Ward-Duong, J. Patience, J. Bulger, G. Van Der Plas, F. Ménard, C. Pinte, A. P. Jackson, G. Bryden, N. J. Turner, P. Harvey, A. Hales, R. J. De Rosa

Astronomy: Faculty Publications

Tracing Slow Winds From T Tauri Stars Via Low-Velocity Forbidden Line Emission, M. N. Simon, I. Pascucci, Suzan Edwards, W. Feng, U. Gorti, D. Hollenbach, E. Rigliaco, J. T. Keane

Astronomy: Faculty Publications

Interpreting Near Infrared Hydrogen Line Ratios In T Tauri Stars, Suzan Edwards

Astronomy: Faculty Publications

Understanding The Origin Of The [Oi] Low-Velocity Component From T Tauri Stars, Elisabetta Rigliaco, Ilaria Pascucci, Uma Gorti, Suzan Edwards, D. Hollenbach

Astronomy: Faculty Publications

Astronomy: Faculty Publications

Characterizing The Iyj Excess Continuum Emission In T Tauri Stars, William J. Fischer, Suzan Edwards, Lynne A. Hillenbrand, John Kwan

Astronomy: Faculty Publications