DIRBE Minus 2MASS: Confirming the Cosmic Infrared Background at 2.2 Microns

Stellar fluxes from the 2MASS catalog are used to remove the contribution due to Galactic stars from the intensity measured by DIRBE in four regions in the North and South Galactic polar caps. After subtracting the interplanetary and galactic foregrounds, a consistent residual intensity of 14.8 +/- 4.6 kJy/sr or 20.2 +/- 6.3 nW/m^2/sr at 2.2 microns is found. At 1.25 microns the residuals show more scatter and are a much smaller fraction of the foreground, leading to a weak limit on the CIRB of 12.0 +/- 6.8 kJy/sr or 28.9 +/- 16.3 nW/m^2/sr (1 sigma).Comment: ApJ in press. 14 pages Latex with 7 included figures. accepted version with 1 new figur

COBE Observations of the Cosmic Infrared Background

The Diffuse InfraRed Background Experiment on COBE measured the total infrared signal seen from space at a distance of 1 astronomical unit from the Sun. Using time variations as the Earth orbits the Sun, it is possible to remove most of the foreground signal produced by the interplanetary dust cloud [zodiacal light]. By correlating the DIRBE signal with the column density of atomic hydrogen measured using the 21 cm line, it is possible to remove most of the foreground signal produced by interstellar dust, although one must still be concerned by dust associated with H_2 (molecular gas) and H II (the warm ionized medium). DIRBE was not able to determine the CIRB in the 5-60 micron wavelength range, but did detect both a far infrared background and a near infrared background. The far infrared background has an integrated intensity of about 34 nW/m^2/sr, while the near infrared and optical extragalactic background has about 59 nW/m^2/sr. The Far InfraRed Absolute Spectrophotometer (FIRAS) on COBE has been used to constrain the long wavelength tail of the far infrared background but a wide range of intensities at 850 microns are compatible with the FIRAS data. Thus the fraction of the CIRB produced by SCUBA sources has large uncertainties in both the numerator and the denominator.Comment: Invited paper presented at the 2nd VERITAS Symposium on TeV Astrophysics of Extragalactic Sources, April 24-26, 2003 at the Adler Planetarium in Chicago. 8 pages LaTeX with 3 embedded figure

Hadwiger Integration of Random Fields

Hadwiger integrals employ the intrinsic volumes as measures for integration of real-valued functions. We provide a formula for the expected values of Hadwiger integrals of Gaussian-related random fields. The expected Hadwiger integrals of random fields are both theoretically interesting and potentially useful in applications such as sensor networks, image processing, and cell dynamics. Furthermore, combining the expected integrals with a functional version of Hadwiger's theorem, we obtain expected values of more general valuations on Gaussian-related random fields

Programmed multiplexing system simultaneously monitors several voltages

System consists of digital voltmeter with binary coded decimal output, programmer, multiplexer, and two to six gated digital displays. Maximum number of circuits monitored is determined by digital voltmeter, rate of change of parameter being measured and complexity of multiplexer design