Preliminary evidence for dust in galactic halos

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

I use B and I photometry of distant galaxies observed through the halos of two nearby spiral galaxies, NGC 2835 and NGC 3521, to test for the existence of dust in galactic halos out to at least a radius of 60 kpc. B-I colors of background galaxies in fields centered along the nearby galaxy's major axis at a projected separation of 60 kpc are compared to the colors of background galaxies in fields centered at a projected separation of about 220 kpc. Background galaxies in the fields at smaller projected separations have average B-I colors that are 0.067±0.033 mag redder than those in the outer fields. Such a result will occur by chance less than 2.2% of the time and so is taken as preliminary evidence that galaxy halos contain more dust at galactic radii of 60 than 220 kpc. A model which assumes that the radial dust profile in galactic disks and halos is a single exponential has a corresponding scale length of 31±8 kpc. I argue on the basis of the IRAS 100 μm flux maps that absorption by Galactic dust is not responsible for this result and briefly discuss connections between this result and other observations of the baryonic component of galaxy halos.

Original languageEnglish (US)
Pages (from-to)1619-1626
Number of pages8
JournalAstronomical Journal
Volume108
Issue number5
StatePublished - Nov 1994
Externally publishedYes

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galactic halos
dust
galaxies
halos
color
radii
Infrared Astronomy Satellite
spiral galaxies
photometry
profiles

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Preliminary evidence for dust in galactic halos. / Zaritsky, Dennis F.

In: Astronomical Journal, Vol. 108, No. 5, 11.1994, p. 1619-1626.

Research output: Contribution to journalArticle

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