Constraints on the Extragalactic Background Light From Very High Energy Gamma-Ray Observations of Blazars

The extragalactic background light (EBL) from the infrared to the ultraviolet is difficult to measure directly, but can be constrained with a variety of methods. The EBL photons absorb γ-rays from distant blazars, allowing one to use blazar spectra from atmospheric Cherenkov telescopes (ACTs) to put upper limits on the EBL by assuming a blazar source spectrum. Here, we apply a simple technique, similar to that developed by Schroedter, to the most recent very high energy (VHE) γ-ray observations of blazars to put upper limits on the EBL energy density. This technique is independent of the EBL model and has well defined errors on the constraints. Our results are consistent with EBL measurements and constraints but marginally inconsistent with several EBL models.