1. Lecture 6:
Gamma-Ray Bursts
Light extinction:
Infrared background

2. Multiwavelength Cosmic Background

3. Extragalactic infrared background effect on blazar spectrum

4. Light curves.
MAGIC (top) and optical R-band data (bottom) obtained for 3C 279 from February to March The long-term baseline for the optical flux is at 3 mJy.
Light curves. MAGIC (top) and optical R-band data (bottom) obtained for 3C 279 from February to March The long-term baseline for the optical flux is at 3 mJy.
MAGIC Collaboration, Albert et al. Science 2008;320:
Published by AAAS

5. Spectrum of 3C 279 measured by MAGIC.
Spectrum of 3C 279 measured by MAGIC. The gray area includes the combined statistical (1σ) and systematic errors, and underlines the marginal significance of detections at high energy. The dotted line shows compatibility of the measured spectrum with a power law of photon index α = 4.1. The blue and red triangles are measurements corrected on the basis of the two models for EBL density.
Spectrum of 3C 279 measured by MAGIC. The gray area includes the combined statistical (1σ) and systematic errors, and underlines the marginal significance of detections at high energy. The dotted line shows compatibility of the measured spectrum with a power law of photon index α = 4.1. The blue and red triangles are measurements corrected on the basis of the two models for EBL density, discussed in the text.

6. Spectral energy distributions of 3C279 at the epochs of MAGIC observations: Feb 2006, Jan 2007, Jan-Feb 2009
Fermi-LAT
2007
2006
2009
Aleksic et al. 2011, arXiv:

7. Stecker et al. 1992, ApJ, 390, L49

8. AGN scheme

9. AGN scheme with various photon fields and geometrical structures

11. The Intergalactic medium Absorbs radiation: Lyman alpha forest
High-z QSO spectra (Becker et al. 2001)
The Intergalactic medium
Absorbs radiation:
Lyman alpha forest
And Lyman continuum
In high redshift quasars:
intervening absorption by
Clouds of neutral hydrogen

12. Typical spectrum of starburst galaxy at z = 0.835 with
GRB host overimposed (red dots)
Paschen limit
Balmer limit

13. Typical spectrum of starburst at z = 2.036 with GRB host
Overimposed (red)
Balmer limit
Lyman limit