# Presentation: 569365

## Sources of contamination in the

- Philadelphia, 22 April 2008

_**Sources of contamination in the**_
_**emission from the Local Bubble**_

**Anjali Gupta**
**Massimiliano Galeazzi**
**Eugenio Ursino**

## Outline

**The Diffuse X-ray background**
**Unidentified point sources**
**Spectral Properties**
**The Warm Hot Intergalactic Medium (WHIM)**
**Spectral properties**
**Angular properties**

- Philadelphia, 22 April 2008

## The Diffuse X-ray Background

- Philadelphia, 22 April 2008

## The Diffuse X-ray Background

**Solar Wind Charge Exchange**

**NH**

**M. Galeazzi and A. Gupta (tomorrow)**

**This Talk**

**NH**

## Identification of the point sources

- Philadelphia, 22 April 2008

**Lockman Hole**

**AXAF Ultra deep F**

**Hubble Deep Field**

**Eridanus Hole**

**Deep Field 1334+37**

***Mosaic images of the targets used in this investigation. The white circles represent the identified point sources.***

## The logN-logS

***The averaged logN-logS  for all the targets used  in our investigation***

**Philadelphia, 22 April 2008**

## Spectral Properties of the point sources

- Philadelphia, 22 April 2008

***Average spectrum of all the sources detected in the ******0.5-2.0 keV****** (black circles) and ******0.4-0.6 keV****** (pink circles) bands.****** ***

***The black and red curve represent the powerlaw fit  with the photon index of ******1.77±0.01******  and ******1.93±0.01******, for  the  two bands respectively.***

## Spectral Properties of the bright and the faint sources

- Philadelphia, 22 April 2008

- Excess
- emission

***Average spectrum of the bright (black) and faint (pink) sources detected in the ******0.5-2.0 KeV.***** **

***The black and red curve represent the powerlaw fit  with the photon index of ******1.87±0.01******  and ******1.40±0.05******, for  the  bright and faint sources respectively.***

***Average spectrum of the bright (black) and faint (pink) sources detected in the ******0.4-0.6 KeV.****** ***

***The black and red curve represent the powerlaw fit  with the photon index of ******2.05±0.01******  and ******1.69±0.04******, for  the  bright and faint sources respectively******.***

## The Warm Hot Intergalactic Medium 

***Spatial distribution of the WHIM at z~0****** ***
***             ***

- Philadelphia, 22 April 2008

- Cen & Ostriker, 1999

- Borgani et al. 2004

## Flux vs. Redshift

***Expected average flux in the energy range ******0.370-0.925 keV****** due to the WHIM as a function of red-shift.***
***The total average flux due to the WHIM is about ******5.7 photons/cm******2******/s/sr***
***The total DXB flux is about ******29.3 photons/cm******2******/s/sr****** (derived using data from McCammon et al., 2002 - ApJ 576, 188).***

- Philadelphia, 22 April 2008

## Spectral Distribution of the WHIM

- Philadelphia, 22 April 2008

## WHIM signature in the Angular distribution of X-ray images

- Philadelphia, 22 April 2008

**Lockman Hole**

**AXAF Ultra deep F**

**Hubble Deep Field**

**Eridanus Hole**

**Deep Field 1334+37**

***Mosaic images of the targets used in this investigation. The white circles represent the identified point sources.***

## AngularAutocorrelation

***Calculated AcF for the two control targets, MBM20 (squares) and the Eridanus hole (full circles), compared with the average AcF  (empty circles).***

***The fraction of X-rays due to the WHIM in the energy band 0.4-0.6 keV is ***
***18******±5%****** ***
***of the total diffuse X-ray emission.***

- Philadelphia, 22 April 2008

## Conclusion

**Solar Wind Charge Exchange**

**NH**

**(18****±5)%**

**(11.7****)%**

- Philadelphia, 22 April 2008

- The End

## Angular Autocorrelation 

- n2 w(Θ)=np2 wp(Θ)+nb2 wb(Θ)+nw2 ww(Θ)

***ACF of the diffuse X-ray background***
***and its components.***

## Acf of Hubble Deep field North