In April 2016 Manchester eScholar was replaced by the University of Manchester’s new Research Information Management System, Pure. In the autumn the University’s research outputs will be available to search and browse via a new Research Portal. Until then the University’s full publication record can be accessed via a temporary portal and the old eScholar content is available to search and browse via this archive.

Related resources

University researcher(s)

    Mid-infrared spectroscopy of nearby red giants

    Grant, Helen Louise

    [Thesis]. Manchester, UK: The University of Manchester; 2020.

    Access to files

    Abstract

    As low- to intermediate-mass stars (< 8 solar masses) evolve along the asymptotic giant branch they experience extreme mass loss due to strong stellar winds, ultimately resulting in stellar death. The driving mechanism for mass loss is not entirely understood, however it is believed to be due to a combination of powerful Mira-like pulsations and thick dusty envelopes. Using high resolution infrared spectroscopy from VISIR, observations of 179 giant stars with L > 700 L (solar) within 300pc of Earth have been obtained. Of these, 33 stars have been identified as potentially dusty. Using the modelling programme DUSTY, dust compositions and mass-loss rates have been determined for five objects, ranging from 10^(-9) to 10^(-6) solar masses per year. Interpretation of these results suggests AGBs spend a longer time evolving at low mass-loss rates, then experience a short period of high mass loss. Analysis of the non-dusty stars has also revealed information about the warm molecular layer of these late-type stars.

    Bibliographic metadata

    Type of resource:
    Content type:
    Form of thesis:
    Type of submission:
    Degree type:
    Master of Science by Research
    Degree programme:
    MSc by Research in Astronomy and Astrophysics
    Publication date:
    Location:
    Manchester, UK
    Total pages:
    153
    Abstract:
    As low- to intermediate-mass stars (< 8 solar masses) evolve along the asymptotic giant branch they experience extreme mass loss due to strong stellar winds, ultimately resulting in stellar death. The driving mechanism for mass loss is not entirely understood, however it is believed to be due to a combination of powerful Mira-like pulsations and thick dusty envelopes. Using high resolution infrared spectroscopy from VISIR, observations of 179 giant stars with L > 700 L (solar) within 300pc of Earth have been obtained. Of these, 33 stars have been identified as potentially dusty. Using the modelling programme DUSTY, dust compositions and mass-loss rates have been determined for five objects, ranging from 10^(-9) to 10^(-6) solar masses per year. Interpretation of these results suggests AGBs spend a longer time evolving at low mass-loss rates, then experience a short period of high mass loss. Analysis of the non-dusty stars has also revealed information about the warm molecular layer of these late-type stars.
    Thesis main supervisor(s):
    Thesis co-supervisor(s):
    Language:
    en

    Institutional metadata

    University researcher(s):

    Record metadata

    Manchester eScholar ID:
    uk-ac-man-scw:323977
    Created by:
    Grant, Helen
    Created:
    10th March, 2020, 14:14:11
    Last modified by:
    Grant, Helen
    Last modified:
    4th January, 2021, 11:29:02

    Can we help?

    The library chat service will be available from 11am-3pm Monday to Friday (excluding Bank Holidays). You can also email your enquiry to us.