O2 Muu julkaisu
Centaurus A: Stellar Metallicity Transition in the Halo
Tekijät: Bird Sarah, Flynn C., Harris W. E., Valtonen M.
Kustantaja: American Astronomical Society
Julkaisuvuosi: 2013
Kokoomateoksen nimi: 221st AAS Meeting - Long Beach, CA January, 2013 : AAS Winter Meeting Abstracts
Sarjan nimi: AAS Meeting
Numero sarjassa: 221
Verkko-osoite: http://adsabs.harvard.edu/abs/2013AAS...22130301B
Tiivistelmä
The very earliest stars in giant galaxies - the most metal-poor halo stars and globular clusters - may have formed before the onset of hierarchical merging, within small pregalactic dwarfs that populated the large-scale dark-matter potential well. Today, these relic stars should be found in a sparse and extremely extended “outermost-halo” component. Finding clear traces of this component in other giant galaxies, and deconvolving it from the more obvious and metal-rich spheroid component generated later by mergers, has been extraordinarily difficult. Now, striking new evidence discovered in M 31 and NGC 3379 suggests that the metal-poor outermost halo can be isolated at very large radii, R > 12Reff . We now have a new deep imaging study with ESO VLT of the nearest giant elliptical and merger remnant, Centaurus A, to search for this extended remnant of the galaxy’s earliest history.
The very earliest stars in giant galaxies - the most metal-poor halo stars and globular clusters - may have formed before the onset of hierarchical merging, within small pregalactic dwarfs that populated the large-scale dark-matter potential well. Today, these relic stars should be found in a sparse and extremely extended “outermost-halo” component. Finding clear traces of this component in other giant galaxies, and deconvolving it from the more obvious and metal-rich spheroid component generated later by mergers, has been extraordinarily difficult. Now, striking new evidence discovered in M 31 and NGC 3379 suggests that the metal-poor outermost halo can be isolated at very large radii, R > 12Reff . We now have a new deep imaging study with ESO VLT of the nearest giant elliptical and merger remnant, Centaurus A, to search for this extended remnant of the galaxy’s earliest history.
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