Preliminary evidence for dust in galactic halos
1994; Institute of Physics; Volume: 108; Linguagem: Inglês
10.1086/117182
ISSN1538-3881
Autores Tópico(s)Astronomy and Astrophysical Research
Resumoview Abstract Citations (73) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Preliminary Evidence for Dust in Galactic Halos Zaritsky, D. 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 micron 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. Publication: The Astronomical Journal Pub Date: November 1994 DOI: 10.1086/117182 Bibcode: 1994AJ....108.1619Z Keywords: Accretion Disks; Astronomical Maps; Astronomical Models; Astronomical Photometry; Galactic Halos; Galactic Structure; Interplanetary Dust; Spiral Galaxies; Stellar Color; Color-Magnitude Diagram; Image Analysis; Radial Distribution; Astronomy; GALAXIES: ISM; GALAXIES: NUCLEI; GALAXIES: STRUCTURE full text sources ADS | data products SIMBAD (2) NED (2)
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