skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: STRONG NEW CONSTRAINTS ON THE EXTRAGALACTIC BACKGROUND LIGHT IN THE NEAR- TO MID-INFRARED

Abstract

Direct measurements of the extragalactic background light (EBL) in the near-IR to mid-IR waveband are extremely difficult due to an overwhelming foreground from the zodiacal light that outshines the faint cosmological diffuse radiation field by more than an order of magnitude. Indirect constraints on the EBL are provided by {gamma}-ray observations of active galactic nuclei. Using the combination of the Fermi Gamma-Ray Space Telescope together with the current generation of ground-based air Cherenkov telescopes (H.E.S.S., MAGIC, and VERITAS) provides unprecedented sensitivity and spectral coverage for constraining the EBL in the near- to mid-IR. In this paper, we present new limits on the EBL based on the analysis of the broadband spectra of a select set of {gamma}-ray blazars covering 200 MeV to several TeV. The EBL intensity at 15 {mu}m is constrained to be 1.36 {+-} 0.58 nW m{sup -2} sr{sup -1}. We find that the fast evolution and baseline EBL models of Stecker et al., as well as the model of Kneiske et al., predict significantly higher EBL intensities in the mid-IR (15 {mu}m) than is allowed by the constraints derived here. In addition, the model of Franceschini et al. and the fiducial model of DomInguez et al. predictmore » near- to mid-IR ratios smaller than that derived from our analysis. Namely, their intensities in the near-IR are too low while their intensities in the mid-IR are marginally too high. All of the aforementioned models are inconsistent with our analysis at the >3{sigma} level.« less

Authors:
;  [1];  [2]
  1. Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)
  2. Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
Publication Date:
OSTI Identifier:
21576757
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 733; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/733/2/77; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; GALAXIES; GALAXY NUCLEI; GAMMA RADIATION; VISIBLE RADIATION; ZODIACAL LIGHT; ELECTROMAGNETIC RADIATION; IONIZING RADIATIONS; RADIATIONS

Citation Formats

Orr, M. R., Krennrich, F., and Dwek, E., E-mail: morr@iastate.edu. STRONG NEW CONSTRAINTS ON THE EXTRAGALACTIC BACKGROUND LIGHT IN THE NEAR- TO MID-INFRARED. United States: N. p., 2011. Web. doi:10.1088/0004-637X/733/2/77.
Orr, M. R., Krennrich, F., & Dwek, E., E-mail: morr@iastate.edu. STRONG NEW CONSTRAINTS ON THE EXTRAGALACTIC BACKGROUND LIGHT IN THE NEAR- TO MID-INFRARED. United States. doi:10.1088/0004-637X/733/2/77.
Orr, M. R., Krennrich, F., and Dwek, E., E-mail: morr@iastate.edu. Wed . "STRONG NEW CONSTRAINTS ON THE EXTRAGALACTIC BACKGROUND LIGHT IN THE NEAR- TO MID-INFRARED". United States. doi:10.1088/0004-637X/733/2/77.
@article{osti_21576757,
title = {STRONG NEW CONSTRAINTS ON THE EXTRAGALACTIC BACKGROUND LIGHT IN THE NEAR- TO MID-INFRARED},
author = {Orr, M. R. and Krennrich, F. and Dwek, E., E-mail: morr@iastate.edu},
abstractNote = {Direct measurements of the extragalactic background light (EBL) in the near-IR to mid-IR waveband are extremely difficult due to an overwhelming foreground from the zodiacal light that outshines the faint cosmological diffuse radiation field by more than an order of magnitude. Indirect constraints on the EBL are provided by {gamma}-ray observations of active galactic nuclei. Using the combination of the Fermi Gamma-Ray Space Telescope together with the current generation of ground-based air Cherenkov telescopes (H.E.S.S., MAGIC, and VERITAS) provides unprecedented sensitivity and spectral coverage for constraining the EBL in the near- to mid-IR. In this paper, we present new limits on the EBL based on the analysis of the broadband spectra of a select set of {gamma}-ray blazars covering 200 MeV to several TeV. The EBL intensity at 15 {mu}m is constrained to be 1.36 {+-} 0.58 nW m{sup -2} sr{sup -1}. We find that the fast evolution and baseline EBL models of Stecker et al., as well as the model of Kneiske et al., predict significantly higher EBL intensities in the mid-IR (15 {mu}m) than is allowed by the constraints derived here. In addition, the model of Franceschini et al. and the fiducial model of DomInguez et al. predict near- to mid-IR ratios smaller than that derived from our analysis. Namely, their intensities in the near-IR are too low while their intensities in the mid-IR are marginally too high. All of the aforementioned models are inconsistent with our analysis at the >3{sigma} level.},
doi = {10.1088/0004-637X/733/2/77},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 733,
place = {United States},
year = {2011},
month = {6}
}