SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Zenn T.) "

Sökning: WFRF:(Zenn T.)

  • Resultat 1-3 av 3
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Meech, K. J., et al. (författare)
  • EPOXI: Comet 103P/Hartley 2 Observations from a Worldwide Campaign
  • 2011
  • Ingår i: Astrophysical Journal Letters. - London : IOP. - 2041-8213 .- 2041-8205. ; 734:L1, s. 1-9
  • Tidskriftsartikel (refereegranskat)abstract
    • Earth- and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths and using techniques that are impossible with an in situ flyby. We report here such observations in support of the EPOXI spacecraft flyby of comet 103P/Hartley 2. The nucleus is small and dark, and exhibited a very rapidly changing rotation period. Prior to the onset of activity, the period was ~16.4?hr. Starting in 2010 August the period changed from 16.6?hr to near 19?hr in December. With respect to dust composition, most volatiles and carbon and nitrogen isotope ratios, the comet is similar to other Jupiter-family comets. What is unusual is the dominance of CO 2 -driven activity near perihelion, which likely persists out to aphelion. Near perihelion the comet nucleus was surrounded by a large halo of water-ice grains that contributed significantly to the total water production.
  •  
2.
  • Bensby, T., et al. (författare)
  • The Nature of the Metal-Rich Thick Disk
  • 2007
  • Ingår i: ASP Conference Proceedings. - 9781583813096 ; 374, s. 181-186
  • Konferensbidrag (refereegranskat)abstract
    • We have traced the Galactic thick disk to its, to date, highest metallicities. Based on high-resolution spectroscopic observations of 187 F and G dwarf stars that kinematically can be associated either with the thin disk (60 stars) or with the thick disk (127 stars), we find that the thick disk stars reach at least solar metallicities, and maybe even higher. This finding is independent of the U_LSR, V_LSR and W_LSR velocities of the stars.
  •  
3.
  • Bensby, T., et al. (författare)
  • Tracing the Galactic Thick Disk to Solar Metallicities
  • 2007
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 663:1, s. 13-16
  • Tidskriftsartikel (refereegranskat)abstract
    • We show that the Galactic thick disk reaches at least solar metallicities and that it experienced strong chemical enrichment during a period of ~3 Gyr, ending around 8-9 Gyr ago. This finding puts further constraints on the relation and interface between the thin and thick disks and their formation processes. Our results are based on a detailed elemental abundance analysis of 261 kinematically selected F and G dwarf stars in the solar neighborhood: 194 likely members of the thick disk and 67 likely members of the thin disk, in the range -1.3<~[Fe/H]<~+0.4. Based on data collected with the 6.5 m Magellan telescopes at the Las Campanas Observatory and with the Very Large Telescope at the European Southern Observatory (ESO proposal 72.B-0179).
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-3 av 3

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy