THE ASTEROID DISTRIBUTION IN THE ECLIPTIC
- Department of Astronomy, School of Physics and Astronomy, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 (United States)
- Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio (Italy)
- Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, I-35122 Padova (Italy)
- Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
- Large Binocular Telescope Observatory, University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721-0065 (United States)
- Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210-1173 (United States)
We present analysis of the asteroid surface density distribution of main-belt asteroids (mean perihelion {delta} {approx_equal} 2.404 AU) in five ecliptic latitude fields, -17 {approx}> {beta}({sup 0}) {approx}< +15, derived from deep Large Binocular Telescope V-band (85% completeness limit V = 21.3 mag) and Spitzer Space Telescope IRAC 8.0 {mu}m (80% completeness limit {approx}103 {mu}Jy) fields enabling us to probe the 0.5-1.0 km diameter asteroid population. We discovered 58 new asteroids in the optical survey as well as 41 new bodies in the Spitzer fields. The derived power-law slopes of the number of asteroids per square degree are similar within each {approx}5{sup 0} ecliptic latitude bin with a mean value of -0.111 {+-} 0.077. For the 23 known asteroids detected in all four IRAC channels mean albedos range from 0.24 {+-} 0.07 to 0.10 {+-} 0.05. No low-albedo asteroids (p{sub V} {approx}< 0.1) were detected in the Spitzer FLS fields, whereas in the SWIRE fields they are frequent. The SWIRE data clearly samples asteroids in the middle and outer belts providing the first estimates of these km-sized asteroids' albedos. Our observed asteroid number densities at optical wavelengths are generally consistent with those derived from the Standard Asteroid Model within the ecliptic plane. However, we find an overdensity at {beta} {approx}> 5{sup 0} in our optical fields, while the infrared number densities are underdense by factors of 2 to 3 at all ecliptic latitudes.
- OSTI ID:
- 21255716
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 137, Issue 6; Other Information: DOI: 10.1088/0004-6256/137/6/5134; Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
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