galactic foreground cleaning in gamma-rays
DESCRIPTION
Galactic Foreground cleaning in gamma-rays. Anisotropy Workshop, June 23 th 2010. Alessandro Cuoco, Oskar Klein Center, Stockholm University. The Microwave sky. In addition to CMB photons, WMAP data is “contaminated” by a number of galactic foregrounds that must be accurately subtracted - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/1.jpg)
Galactic Foreground cleaning in Galactic Foreground cleaning in gamma-rays gamma-rays
Alessandro Cuoco,Oskar Klein Center,
Stockholm University
Anisotropy Workshop,
June 23th 2010
![Page 2: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/2.jpg)
The Microwave skyThe Microwave sky•In addition to CMB photons, WMAP data is “contaminated” by a number of galactic foregrounds that must be accurately subtracted
•The WMAP frequency range is well suited to minimize the impact of foregrounds
•Substantial challenges are involved in identifying and removing foregrounds
![Page 3: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/3.jpg)
Template fittingTemplate fitting
![Page 4: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/4.jpg)
+
+
+
Syn
chro
tron
Fre
e-f
ree
T &
S
Du
stC
MB
WMAP
Synchrotron: Synchrotron: Template: C.G.T. Haslam et al., A&A Template: C.G.T. Haslam et al., A&A 100 (1981) 100 (1981) 209.209.
CMB: CMB: Gold et al., Gold et al., arXiV:1001.4555arXiV:1001.4555..
Freefree: Freefree: Template: D.P. Finkbeiner, ApJS Template: D.P. Finkbeiner, ApJS 146 (2003) 146 (2003) 407.407.
Dust:Dust: Template: D.P. Finkbeineret al., ApJ Template: D.P. Finkbeineret al., ApJ 524 (1999) 524 (1999) 867.867.
TOTATOTALL
![Page 5: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/5.jpg)
The “WMAP Haze”The “WMAP Haze”
After known foregrounds are subtracted, an excess appears in the residual maps within the inner ~20 around the Galactic
Center
D. P. Finkbeiner, Astrophys. J. 614 (2004) 186
G. Dobler and D. P. Finkbeiner, arXiv:0712.1038 [astro-ph].
![Page 6: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/6.jpg)
WMAP Team foreground analysis and WMAP Team foreground analysis and the Hazethe Haze
WMAP Collaboration (B. Gold et al.) 2008[arXiv:astro-ph/0803.0715].
D.T. Cumberbatch,, arXiv:0902.0039 [astro-ph].
Map of the synchrotron spectral indexes in a pixel by pixel fit procedure by WMAP
Synchrotron spectral indexes averaged along constant longitudes stripes by WMAP
The fit procedure used for the haze extraction is quite important, and using more degrees of freedom to model the foregrounds as performed by the WMAP team fails in finding the feature. They still find an hardening of the synchrotron emission in the Haze region, though.
![Page 7: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/7.jpg)
The Gamma SkyThe Gamma Sky
Galprop Galprop Foregrounds Model:Foregrounds Model:
Galactic Contribution from: 1. Pion Decay 2. Inverse Compton 3. Electron Bremsstrahlung
Moskalenko et al.Moskalenko et al.
![Page 8: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/8.jpg)
![Page 9: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/9.jpg)
![Page 10: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/10.jpg)
Morphology of the gamma-sky Morphology of the gamma-sky componentscomponents
![Page 11: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/11.jpg)
Dobler, Finkbeiner et al. 2009Dobler, Finkbeiner et al. 2009
A Fermi Haze?
![Page 12: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/12.jpg)
![Page 13: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/13.jpg)
Further directions:Further directions:
Multi-template fitting using gas rings?Multi-template fitting using gas rings?
![Page 14: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/14.jpg)
![Page 15: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/15.jpg)
More directions:More directions:
Planck dust map(s) as gas templatesPlanck dust map(s) as gas templates
![Page 16: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/16.jpg)
![Page 17: Galactic Foreground cleaning in gamma-rays](https://reader035.vdocuments.net/reader035/viewer/2022062723/56813e31550346895da814b0/html5/thumbnails/17.jpg)
Lot of work to do…Lot of work to do…