OBSERVATIONS AND BOWSHOCK MODELS OF HERBIG-HARO OBJECTS (STAR FORMATION, BIPOLAR OUTFLOWS).

Persistent Link:
http://hdl.handle.net/10150/184022
Title:
OBSERVATIONS AND BOWSHOCK MODELS OF HERBIG-HARO OBJECTS (STAR FORMATION, BIPOLAR OUTFLOWS).
Author:
HARTIGAN, PATRICK MICHAEL.
Issue Date:
1987
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Herbig-Haro (HH) objects are small nebulous regions of shock excited gas associated with bipolar outflows from newly formed stars. This dissertation presents an extensive set of observational data on Herbig-Haro objects, including deep CCD images, medium resolution long-slit spectra, and high resolution echelle spectra. The CCD survey indicates that HH objects cannot be identified reliably on the basis of morphology alone. The spectral line data show that HH objects exhibit enormous linewidths even though the objects are only about 1500 AU in size. The spectra sometimes have two velocity peaks, and show spatial separation of the high and low radial velocity gas. A radiative bowshock model constructed from a series of planar shock models accounts for the large linewidths, unusual line profiles, line ratios, and spatial structure seen in HH objects. A simple formula is derived that relates the shock velocity and orientation angle of a radiating bowshock to the observed maximum and minimum radial velocities seen in a line profile. The bowshock forms around a 'bullet' of material ejected from the forming star. The most likely acceleration mechanism for the bullet seems to be a breakup of a collimated stellar jet.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Stars -- Formation.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Planetary Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Lada, Charlie

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleOBSERVATIONS AND BOWSHOCK MODELS OF HERBIG-HARO OBJECTS (STAR FORMATION, BIPOLAR OUTFLOWS).en_US
dc.creatorHARTIGAN, PATRICK MICHAEL.en_US
dc.contributor.authorHARTIGAN, PATRICK MICHAEL.en_US
dc.date.issued1987en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractHerbig-Haro (HH) objects are small nebulous regions of shock excited gas associated with bipolar outflows from newly formed stars. This dissertation presents an extensive set of observational data on Herbig-Haro objects, including deep CCD images, medium resolution long-slit spectra, and high resolution echelle spectra. The CCD survey indicates that HH objects cannot be identified reliably on the basis of morphology alone. The spectral line data show that HH objects exhibit enormous linewidths even though the objects are only about 1500 AU in size. The spectra sometimes have two velocity peaks, and show spatial separation of the high and low radial velocity gas. A radiative bowshock model constructed from a series of planar shock models accounts for the large linewidths, unusual line profiles, line ratios, and spatial structure seen in HH objects. A simple formula is derived that relates the shock velocity and orientation angle of a radiating bowshock to the observed maximum and minimum radial velocities seen in a line profile. The bowshock forms around a 'bullet' of material ejected from the forming star. The most likely acceleration mechanism for the bullet seems to be a breakup of a collimated stellar jet.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectStars -- Formation.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePlanetary Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorLada, Charlieen_US
dc.identifier.proquest8711632en_US
dc.identifier.oclc698376448en_US
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