Red Halos Revealed by Surface Photometry

• There are two complementary techniques for studying the luminous halos of galaxies: direct star counts and surface photometry. Star counts can trace the structure of stellar halos out to much larger projected distances, but surface photometry gives a more direct measurement of surface brightness. Curiously, a number of attempts to study the halos of galaxies through optical/near-infrared surface photometry have revealed integrated colours that are too red to be reconciled with the halo properties inferred from the study of resolved stars. We argue that these anomalously red colours can be explained either by a stellar halo population with a bottom-heavy initial mass function, or by dust extinction of extragalactic background light.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

Star counts

distribution

and statistics

Photometric

polarimetric

and spectroscopic instrumentation

Luminosity and mass functions

Dwarf galaxies

Magnitudes and colors

luminosities

Astronomy and astrophysics

Astronomi och astrofysik

Publikations- och innehållstyp

vet (ämneskategori)

kon (ämneskategori)