Detailed optical study of HH 32 and the highly collimated outflow from the T Tauri star AS 353A

Journal Article · Sun Jun 01 04:00:00 EDT 1986 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/114111· OSTI ID:5717203

Hartigan, P; Mundt, R; Stocke, J

The T Tauri star AS 353A and its highly collimated bipolar outflow have been studied using medium- and high-resolution spectroscopy and deep emission-line CCD imagery. We report the discovery of a linear emission jet in the redshifted part of the flow, and present spectra of the HH objects (HH 32A--D) that confirm the bipolarity of the flow. Despite widely varying line profiles, all four HH objects have similar extremely broad emission linewidths and maximum radial velocities (approx.400 km/s) as well as nearly constant number density as a function of radial velocity. Three of the four objects (HH 32D is the possible exception) possess prominent double-peaked emission-line profiles, and in HH 32A and HH 32C the high-velocity component is situated closer to the star than the low-velocity component. The line profile of (O III) lambda5007 differs markedly from the profiles of lower-excitation lines for HH 32A. These characteristics are examined in the light of two physical models: HH objects as strongly radiating shocks in outflowing jets or as single bow shocks around dense clumps in the outflow. Both are successful in explaining the majority of characteristics observed, but both models encounter some difficulties. The stellar wind has been studied through examination of the star's emission and absorption lines, and we find that the wind is already accelerated to 300 km/s close to the star, and reaches a terminal velocity in excess of 350 km/s. The blueshifted component of the H..cap alpha.. profile of AS 353A is highly variable, and the profiles of different lines have quite dissimilar characteristics. The P Cygni line profiles are discussed briefly in terms of two wind models. There is evidence that the flow collimation occurs at distances greater than two stellar radii.

• Research Organization: Department of Planetary Sciences, University of Arizona, Tucson, Arizona 85721
• OSTI ID: 5717203
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 91:6; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC GASES
ERUPTIVE VARIABLE STARS
FLUID FLOW
FLUIDS
GAS FLOW
GASES
JETS
LUMINOSITY
MASS TRANSFER
MATHEMATICAL MODELS
MORPHOLOGY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SPECTRA
STAR MODELS
STARS
STELLAR ACTIVITY
STELLAR WINDS
T TAURI STARS
VARIABLE STARS
VISIBLE SPECTRA