Imaging the HL Tauri Disk at λ = 2.7 Millimeters with the BIMA Array

Mundy, Lee G.; Looney, Leslie W.; Erickson, W. C.; Grossman, A. W.; Welch, W. J.; Forster, J. R.; Wright, M. C. H.; Plambeck, R. L.; Lugten, J. B.; Thornton, D.

doi:10.1086/310117

Cited by 113 publications

(109 citation statements)

References 30 publications

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“…The best match, in this case, is for R ∼ 100 AU, the residuals are marginally larger than in the p = 1.0 and 1.5 best models, but the difference is not really significant. The dependence of the outer radius on the surface density law is not unexpected, see also the discussion of Mundy et al (1996). In all cases the outer radius is slightly or significantly larger than the FWHM radius derived from the 2D Gaussian deconvolution of the 7 mm map; especially if p ≥ 1, our observations are consistent with CQ Tau having a rather large disk, comparable in size to the CO disks observed around other Herbig Ae stars (Mannings & Sargent 1997, 2000.…”

Section: Modelssupporting

confidence: 79%

Large grains in the disk of CQ Tau

Testi

Natta

Shepherd

et al. 2003

A&A

195

193

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Abstract. We present 7 mm observations of the dusty disk surrounding the 10 Myr old 1.5 M pre-main-sequence star CQ Tauri obtained at the Very Large Array with 0.8 arcsec resolution and 0.1 mJy rms sensitivity. These observations resolve the 7 mm emission in approximately the north-south direction, confirming previous results obtained with lower resolution. We use a twolayer flared disk model to interpret the observed fluxes from 7 mm to 1.3 mm together with the resolved 7 mm structure. We find that the disk radius is constrained to the range 100 to 300 AU, depending on the steepness of the disk surface density distribution. The power law index of the dust opacity coefficient, β, is constrained to be 0.5 to 0.7. Since the models indicate that the disk is optically thin at millimeter wavelengths for radii greater than 8 AU, the contribution of an optically thick region to the emission is less than 10%. This implies that high optical depth or complex disk geometry cannot be the cause of the observed shallow millimeter spectral index. Instead, the new analysis supports the earlier suggestion that dust particles in the disk have grown to sizes as large as a few centimeters. The dust in the CQ Tauri system appears to be evolved much like that in the TW Hydra system, a well-studied pre-main-sequence star of similar age and lower mass. The survival of gas-rich disks with incomplete grain evolution at such old ages deserves further investigations.

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Section: Modelssupporting

confidence: 79%

Large grains in the disk of CQ Tau

Testi

Natta

Shepherd

et al. 2003

A&A

195

193

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“…Mundt et al (1990) determined the jet direction (PA = 51 • ) using [SII]-continuum imaging. Using different techniques, several works determined a consistent disk PA around of 125 • (Lay et al 1994;Mundy et al 1996;Wilner et al 1996;Close et al 1997;Murakawa et al 2008). Different disk PAs were found in Sargent & Beckwith (1991 The evidence of a jet and disk, along with our NIR polarization PA (124 • ± 1 • ), is consistent with an optically thick dusty disk in HL Tau (Fig.…”

Section: Hl Tausupporting

confidence: 76%

Near infrared polarimetry of a sample of YSOs

Pereyra

Girart

Magalhães

et al. 2009

A&A

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Aims. Our goal is to study the physical properties of the circumstellar environment of young stellar objetcs (YSOs). In particular, the determination of the scattering mechanism can help us to constrain the optical depth of the disk and/or envelope in the near infrared. Methods. We used the IAGPOL imaging polarimeter along with the CamIV infrared camera at the LNA observatory to obtain near infrared polarimetry measurements in the H band of a sample of optically visible YSOs, namely, eleven T Tauri stars and eight Herbig Ae/Be stars. An independent determination of the disk (or jet) orientation was obtained for twelve objects from the literature. The circumstellar optical depth could then be estimated by comparing the integrated polarization position angle (PA) with the direction of the major axis of the disk projected onto the plane of the sky. Optically thin disks have, in general, a polarization PA that is perpendicular to the disk plane. In contrast, optically thick disks have polarization PAs parallel to the disks. Results. Among the T Tauri stars, three are consistent with having optically thin disks (AS 353A, RY Tau and UY Aur) and five with optically thick disks (V536 Aql, DG Tau, DO Tau, HL Tau and LkHα 358). Among the Herbig Ae/Be stars, two stars exhibit evidence of optically thin disks (Hen 3-1191 and VV Ser) and two of optically thick disks (PDS 453 and MWC 297). Our results seem consistent with optically thick disks at near infrared bands, which are more likely to be associated with younger YSOs. Marginal evidence of polarization reversal is found in RY Tau, RY Ori, WW Vul, and UY Aur. In the first three cases, this feature can be associated with the UXOR phenomenon. Correlations with the IRAS colors and the spectral index yielded evidence of an evolutionary segregation in which the disks tend to be optically thin when they are older.

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“…By using such models, the disk sizes generally increase by 20-30 AU with the addition of an unresolved point flux, which is comparable to the uniform disk models. Such models were first introduced by Mundy et al (1996) since the mm emission seems to be more centrally peaked than a single Gaussian. The unresolved point flux is more likely due to the unresolved disk structure since the free-free emission contribution is expected to be low toward Class I sources (Hogerheijde et al 1998).…”

Section: Gaussian Diskmentioning

confidence: 99%

Rotationally-supported disks around Class I sources in Taurus: disk formation constraints

Harsono

Jørgensen

Dishoeck

et al. 2014

A&A

127

169

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Context. Disks are observed around pre-main sequence stars, but how and when they form is still heavily debated. While disks around young stellar objects have been identified through thermal dust emission, spatially and spectrally resolved molecular line observations are needed to determine their nature. Only a handful of embedded rotationally supported disks have been identified to date. Aims. We identify and characterize rotationally supported disks near the end of the main accretion phase of low-mass protostars by comparing their gas and dust structures. Methods. Subarcsecond observations of dust and gas toward four Class I low-mass young stellar objects in Taurus are presented at significantly higher sensitivity than previous studies. The 13 CO and C 18 O J = 2-1 transitions at 220 GHz were observed with the Plateau de Bure Interferometer at a spatial resolution of ≤0.8 (56 AU radius at 140 pc) and analyzed using uv-space position velocity diagrams to determine the nature of their observed velocity gradient. Results. Rotationally supported disks (RSDs) are detected around 3 of the 4 Class I sources studied. The derived masses identify them as Stage I objects; i.e., their stellar mass is higher than their envelope and disk masses. The outer radii of the Keplerian disks toward our sample of Class I sources are ≤100 AU. The lack of on-source C 18 O emission for TMR1 puts an upper limit of 50 AU on its size. Flattened structures at radii >100 AU around these sources are dominated by infalling motion (υ ∝ r −1 ). A large-scale envelope model is required to estimate the basic parameters of the flattened structure from spatially resolved continuum data. Similarities and differences between the gas and dust disk are discussed. Combined with literature data, the sizes of the RSDs around Class I objects are best described with evolutionary models with an initial rotation of Ω = 10 −14 Hz and slow sound speeds. Based on the comparison of gas and dust disk masses, little CO is frozen out within 100 AU in these disks. Conclusions. Rotationally supported disks with radii up to 100 AU are present around Class I embedded objects. Larger surveys of both Class 0 and I objects are needed to determine whether most disks form late or early in the embedded phase.

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Imaging the HL Tauri Disk at λ = 2.7 Millimeters with the BIMA Array

Cited by 113 publications

References 30 publications

Large grains in the disk of CQ Tau

Large grains in the disk of CQ Tau

Near infrared polarimetry of a sample of YSOs

Rotationally-supported disks around Class I sources in Taurus: disk formation constraints

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