Published January 4, 2006 | Version v1
Report

Extended Source Gamma-Ray Emission from WIMP Annihilation in the Sagittarius Dwarf Elliptical Galaxy (SULI paper)

  • 1. Columbia U., SLAC (United States)

Description

The proximity of the dark matter dominated Sagittarius Dwarf Elliptical Galaxy (position (l,b) = 5.6o, -14o) allows it to act as an ideal laboratory for the exploration of extended gamma-ray emission from Weakly Interacting Massive Particle (WIMP) annihilation processes in a dark matter-dominated system. Since the matter in our universe is predominantly dark, exploring such processes as WIMP annihilation will lead to a better understanding of cosmology. In order to study this gamma-ray emission, a model for the diffuse background gamma-radiation in the dwarf galaxy's region is extracted from the Energetic Gamma Ray Experiment Telescope (EGRET) data. After validating this model and comparing it to the EGRET diffuse model, the background model is added to effective bleeding-contamination from external point sources and multiple models for the signal-above-background emission. Various models of this emission are tested: (a) no source located in region, (b) unidentified point source 3EG J1847-3219 from the Third EGRET Catalog responsible for the emission and (c) extended emission resulting from WIMP annihilation responsible for the signal above background. These models are created through the employment of Monte Carlo simulation methods, utilizing the response functions of the EGRET instrument to simulate the point spread function, energy dispersion and effects of variable effective area depending on angle of incidence. Energy spectra for point sources are generated from the best predictions of spectral indices listed in the Third EGRET Catalog and the spectrum for the extended dark matter source is generated from Pythia high energy annihilation simulations. Hypothesis testing is conducted to assess the goodness-of-fit of these models to the data taken by EGRET. Additionally, we hope to expand our analysis by employing the response functions of the imminent Gamma Ray Large Area Space Telescope (GLAST) to our models. This extension should highlight the sensitivity disparities between GLAST and EGRET and show GLAST's potential enhancement of this analysis. This process will allow for forecasting of extended WIMP annihilation emission signatures for the GLAST detector

Availability note (English)

Available from http://www.slac.stanford.edu/cgi-wrap/pubpage?slac-tn-05-076.html; OSTI as DE00877991; PURL: https://www.osti.gov/servlets/purl/877991-4Hmybs/

Additional details

Publishing Information

Imprint Pagination
25 p.
Report number
SLAC-TN--05-076

INIS

Country of Publication
United States
Country of Input or Organization
United States
INIS RN
37071016
Subject category
S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; S73: NUCLEAR PHYSICS AND RADIATION PHYSICS;
Resource subtype / Literary indicator
Non-conventional Literature
Descriptors DEI
ANNIHILATION; COSMOLOGY; ENERGY SPECTRA; GAMMA RADIATION; INCIDENCE ANGLE; NONLUMINOUS MATTER; POINT SOURCES; RESPONSE FUNCTIONS; SENSITIVITY; TESTING; UNIVERSE
Descriptors DEC
ELECTROMAGNETIC RADIATION; FUNCTIONS; INTERACTIONS; IONIZING RADIATIONS; MATTER; PARTICLE INTERACTIONS; RADIATION SOURCES; RADIATIONS; SPECTRA

Optional Information

Contract/Grant/Project number
AC02-76SF00515
Funding organization
US Department of Energy (United States)