Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-05-27
Astrophys.J.667:11-25,2007
Astronomy and Astrophysics
Astrophysics
38 pages, 8 figures. Accepted for publication in ApJ
Scientific paper
10.1086/520079
Determination of the cosmic infrared background (CIB) at far infrared wavelengths using COBE/DIRBE data is limited by the accuracy to which foreground interplanetary and Galactic dust emission can be modeled and subtracted. Previous determinations of the far infrared CIB (e.g., Hauser et al. 1998) were based on the detection of residual isotropic emission in skymaps from which the emission from interplanetary dust and the neutral interstellar medium were removed. In this paper we use the Wisconsin H-alpha Mapper (WHAM) Northern Sky Survey as a tracer of the ionized medium to examine the effect of this foreground component on determination of the CIB. We decompose the DIRBE far infrared data for five high Galactic latitude regions into H I and H-alpha correlated components and a residual component. We find the H-alpha correlated component to be consistent with zero for each region, and we find that addition of an H-alpha correlated component in modeling the foreground emission has negligible effect on derived CIB results. Our CIB detections and 2 sigma upper limits are essentially the same as those derived by Hauser et al. and are given by nu I_nu (nW m-2 sr-1) < 75, < 32, 25 +- 8, and 13 +- 3 at 60, 100, 140, and 240 microns, respectively. Our residuals have not been subjected to a detailed anisotropy test, so our CIB results do not supersede those of Hauser et al. We derive upper limits on the 100 micron emissivity of the ionized medium that are typically about 40% of the 100 micron emissivity of the neutral atomic medium. This low value may be caused in part by a lower dust-to-gas mass ratio in the ionized medium than in the neutral medium, and in part by a shortcoming of using H-alpha intensity as a tracer of far infrared emission.
Arendt Richard G.
Dwek Eli
Haffner Matthew L.
Hauser Michael G.
Odegard Nils
No associations
LandOfFree
Determination of the Far-Infrared Cosmic Background Using COBE/DIRBE and WHAM Data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Determination of the Far-Infrared Cosmic Background Using COBE/DIRBE and WHAM Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Determination of the Far-Infrared Cosmic Background Using COBE/DIRBE and WHAM Data will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-99289