Hydrogen line and continuum emission in young stellar objects. II - Theoretical results and observational constraints

Journal Article · Wed Mar 01 04:00:00 EST 1989 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/167208· OSTI ID:6225184

Alonso-costa, J L; Kwan, JOHN

Theoretical results for H I emission from YSOs are compared with available observations. IR line and radio continuum properties have been gathered for 29 objects that include a number of T Tau stars, several emission-line stars with IR excesses, and many heavily obscured luminous YSOs. The present excitation model can account for the observed Brackett line and radio continuum fluxes of YSOs with luminosities of 20-100,000 solar luminosities. It is argued that the observed Br-alpha line and 6-cm free-free continuum emissions are best explained in terms of a core-halo structure. The small core (ranging from r less than about 30 AU for a 10,000-solar luminosity YSO to r less than about 0.2 AU for a 10-solar luminosity YSO) is responsible for generating the strong IR line fluxes, while the surrounding diffuse halo dominates the 6-cm emission. 62 refs.

• Research Organization: Massachusetts Univ., Amherst (USA); Massachusetts, University, Amherst
• OSTI ID: 6225184
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 338; ISSN ASJOA
• 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
BALMER LINES
COMPARATIVE EVALUATIONS
CORRELATIONS
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
ERUPTIVE VARIABLE STARS
INFRARED RADIATION
LUMINOSITY
MORPHOLOGY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PROTOSTARS
RADIATIONS
RADIOWAVE RADIATION
SPECTRA
STARS
T TAURI STARS
VARIABLE STARS