Sökning: "interstellar medium: molecules"

Visar resultat 16 - 20 av 24 avhandlingar innehållade orden interstellar medium: molecules.

1. 16. Molecular observations at high and low redshifts with the Odin satellite

   Författare :Carina Persson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ISM: abundances -- ISM: molecules -- ISM: individual Orion KL -- ISM: individual S140 -- Radio lines: ISM -- Submillimeter -- Line: profiles -- Line: formation -- Cosmology: early Universe -- Cosmology: observations;

   Sammanfattning : The papers in this thesis have the aim of expanding our knowledge of different processes related to star formation in the early Universe and at present times. A complex chemistry occurs in star forming clouds and by observing molecules, information about the necessary physical and chemical conditions for star formation can be obtained. LÄS MER

3. 17. The death throes of massive stars

   Författare :Sofia Wallström; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; submillimeter: ISM -- ISM: supernova remnants -- ISM: individual objects: Cassiopeia A -- circumstellar matter -- stars: AGB and post-AGB -- stars: mass-loss -- stars: individual: IRAS 17163-3907 -- quasars: absorption lines -- quasars: individual: B 0218 357 -- galaxies: ISM -- galaxies: abundances -- ISM: molecules;

   Sammanfattning : Massive evolved stars affect their local surroundings as they go through phases of intense mass-loss and eventually explode as supernovae, adding kinetic energy and freshly synthesised material to the interstellar medium. The circumstellar material ejected by the star affects the shape and evolution of the future supernova remnant, and how the material is incorporated into the interstellar medium. LÄS MER

4. 18. Molecular Astrophysics in Star-forming Regions with the Odin Satellite

   Författare :Carina Persson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The interstellar medium is the cradle of life, stars and planets in the evolving Universe. Stars are born deep inside cold and dark molecular clouds, and affect the dynamical conditions in local regions by powerful winds, outflows, and by supernova explosions. LÄS MER

5. 19. Astrochemical Surface Science: Water Desorption from Nanostructured Graphite

   Författare :Anna Clemens; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; intercalation; temperature programmed desorption; diffuse reflection; geometrical resonances; water ice; ultra high vacuum;

   Sammanfattning : To date, around 180 different molecules have been identified in the interstellar medium (ISM). Some of them form molecular ices on cold interstellar dust grain surfaces. An interstellar dust grain particle is in the order of nanometres in size and is usually composed of a carbonaceous or silicatious grain core. LÄS MER

7. 20. UV Chemistry in the Circumstellar Envelopes of Evolved Stars

   Författare :Maryam Saberi; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astrochemistry – molecular processes – stars: abundances – AGB – binaries – circumstellar matter – chromospheres – ultraviolet;

   Sammanfattning : Low- and intermediate-mass stars eject a substantial amount of their material into space during a late phase of stellar evolution, the asymptotic giant branch (AGB) phase. Therefore, they impact the chemistry of the interstellar medium. Due to the intense mass loss, a circumstellar envelope (CSE), rich in gas and dust, forms around the AGB star. LÄS MER