TY - JOUR
T1 - First Spitzer Space Telescope observations of magnetic cataclysmic variables
T2 - Evidence of excess emission at 3-8 μm
AU - Howell, Steve B.
AU - Brinkworth, Carolyn
AU - Hoard, D. W.
AU - Wachter, Stefanie
AU - Harrison, Thomas
AU - Chun, Howard
AU - Thomas, Beth
AU - Stefaniak, Linda
AU - Ciardi, David R.
AU - Szkody, Paula
AU - Van Belle, Gerard
PY - 2006/7/20
Y1 - 2006/7/20
N2 - We present the first observations of magnetic cataclysmic variables using the Spitzer Space Telescope. We used the Infrared Array Camera to obtain photometry of the Polars EF Eri, GG Leo, V347 Pav, and RX J0154.0-5947 at 3.6, 4.5, 5.8, and 8.0 μm, respectively. In all of our targets, we detect excess mid-infrared emission over that expected from the component stars alone. We explore the origin of this IR excess by examining bremsstrahlung, cyclotron emission, circumbinary dust, and L/T brown dwarf secondary stars. Bremsstrahlung and cyclotron emission appear unlikely to be significant contributors to the observed fluxes. At present, the most likely candidate for the excess emission is dust that is probably located in a circumbinary disk with an inner temperature near 800 K. However, a simple dust disk plus any reasonable low-mass or brown dwarf-like secondary star is unable to fully explain the observed flux densities in the 3-8 μm region.
AB - We present the first observations of magnetic cataclysmic variables using the Spitzer Space Telescope. We used the Infrared Array Camera to obtain photometry of the Polars EF Eri, GG Leo, V347 Pav, and RX J0154.0-5947 at 3.6, 4.5, 5.8, and 8.0 μm, respectively. In all of our targets, we detect excess mid-infrared emission over that expected from the component stars alone. We explore the origin of this IR excess by examining bremsstrahlung, cyclotron emission, circumbinary dust, and L/T brown dwarf secondary stars. Bremsstrahlung and cyclotron emission appear unlikely to be significant contributors to the observed fluxes. At present, the most likely candidate for the excess emission is dust that is probably located in a circumbinary disk with an inner temperature near 800 K. However, a simple dust disk plus any reasonable low-mass or brown dwarf-like secondary star is unable to fully explain the observed flux densities in the 3-8 μm region.
KW - Stars: individual (EF Eridani, GG Leonis, V347 Pavonis, RX J0154.0-5947)
KW - Stars: low-mass, brown dwarfs
UR - https://www.scopus.com/pages/publications/33747494580
U2 - 10.1086/506558
DO - 10.1086/506558
M3 - Article
AN - SCOPUS:33747494580
SN - 0004-637X
VL - 646
SP - L65-L68
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - II
ER -