A catalogue of potential ν-signals of galactic γ-ray sources · > MAGIC: Located in Canary...
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A catalogue of potential ν-signals of galactic γ-ray sources Summerschool DESY Zeuthen 2011 Basho Kaminsky Zeuthen, 07. September 2011
Transcript of A catalogue of potential ν-signals of galactic γ-ray sources · > MAGIC: Located in Canary...
A catalogue of potential ν-signals ofgalactic γ-ray sources
Summerschool DESY Zeuthen 2011
Basho KaminskyZeuthen, 07. September 2011
My Project
> Project: Derive expected neutrino flux from measured gamma-ray flux for galactic gamma-ray sources
> Collecting the data from various γ telescopes
> Consider detector characteristics
> Extract the spectral flux of the sources
> Expected neutrino flux depends on the source type and model
> Compute the flux for the specific detectors:
KM3NeT, IceCube
γ Ray Telescopes – Air Shower Telescopes
> HESS:
Located in Namibia, 4 telescopes
Angular resolution better then 0.1deg
Energy range: 100GeV to 100 TeV
> MAGIC:
Located in Canary Islands, 2 air shower telescopes
angular resolution 0.1deg
Energy range: 0.025 – 30 TeV
> VERITAS:
Located in South Arizona, 4 telescopes
Angular resolution is better 0.15deg
Energy range: 50 GeV – 50 TeV
γ Ray Telescopes – FERMI
> FERMI:
Satellite mission, started 2008
Main instrument: Large Area Telescope (LAT)
Energy range: 20 MeV - 300 GeV
Angular resolution: 3deg at 100MeV, 0.04deg at 100 GeV
Used data from: FERMI LAT 2-Year Source Catalog
Neutrino Telescopes – IceCube
> Neutrino telescope at the South Pole
> Detector volume: 1 km³
> Measures Cherenkov light
> Sensitive for all 3 neutrino flavors
> time resolution of 5ns
> Energy range: 100 GeV threshold up to PeV regime
> Angular resolution better than 1deg
Neutrino Telescopes – KM3NeT
> Future neutrino telescope
> Higher possibility to find galactic sources due to its position in the Northern Hemisphere:planned in the Mediterranean Sea
> Detector volume: km3
> Angular resolution (planned):better than 0.1deg above 10TeV
> See all 3 neutrino flavors
> Threshold: several hundreds of GeV
> Construction expected to start in 2012
Gamma Sources – Potential Neutrino Sources
> SNR (Supernova Remnant):
Detection of TeV gamma rays provides evidence for
effective particle acceleration
If p accelerated, emission of gamma rays and neutrinos
Example: CTB 37A
> HMB (High Mass Binary):
Binary systems of massive star and compact object
Relativistic jets accelerate particles up to TeV
Example: PSR B1259-63
> PWN (Pulsar Wind Nebula):
Emissions of nebula caused by pulsar wind
Represent some of the brightest TeV gamma ray sources
Example: PSR J1301-6305
Gamma to Neutrino Flux – Parametrization
p+p → p+p+π+/0
> ν production: π+ → μ+νμ → e+ ν
e ν
μ ν
μ
> γ production: π0 → γ γ
> parametrization of proton & secondary particles spectra:
power law with exponential cutoff:
> Assumptions:
No Absorption inside the source
Pions decay before interacting
Source distant enough for full neutrino mixing
Valid above 100 GeV
> p+p → p+p+π+/0
> ν production: π+ → μ+νμ → e+ ν
e ν
μ v
μ
> γ production:
> p+p → p+p+π+/0
> ν production: π+ → μ+νμ → e+ ν
e ν
μ v
μ
> γ production:
dNdE
≈k °E−g°eE / p
Gamma to Neutrino Flux – Detector Properties
> Measurable event rate depends on:
Spectrum
Effective area
of the detector
Gamma to Neutrino Flux – Effective Area
>
> Aeff=N ARN R
N=∭ dt dw dE
dNdE
t , E ,wAeff E ,w
Gamma to Neutrino Flux – Detector Properties
> Measurable event rate depends on:
Spectrum
Effective area
of the detector
Background rate
Visibility of the source
for the detector
> Both neutrino telescopes show energy thresholds similar to threshold of Cherenkov air shower telescopes, threshold & energy range of FERMI for most part below threshold of the neutrino telescopes
> Considers also loss of neutrinos outside the search window
> Measurable event rate depends on:
Spectrum
Effective area
of the detector
Background rate
Visibility of the source
for the detector
> Both neutrino telescopes show energy thresholds similar to threshold of Cherenkov air shower telescopes, threshold & energy range of FERMI for most part below threshold of the neutrino telescopes
> Considers also loss of neutrinos outside the search window
Result – Source Catalog
> Contains now 107 sources (multiple appearance possible)
> Generated automatically from the file with the sources and files containing the gamma spectra
Result – Details for a Source
> Example: PSR J1301-6305
> For KM3NeT:
Visibility: 100%
Number of events: Pure PL spectrum:
Mean = 6.53
Min = 3.97 Max = 9.09
PL With cut-off:
Mean = 2.35
Min = 1.28 Max = 3.44
Result – Details
Events vs Ethresh
without curved spectrum
Result – Additions
> In future: possibility to compare expected with measured values
> Measure if hadronic interaction processes are responsible for bulk of high-energy emission
> Possibility to chose promising sources for observations
> Continuation: Include more detailed parametrizations of proton and secondary spectra
> Want to thank:
Organizers of the DESY Summer Student Programme
My SVs: Markus Ackermann & Alexander Kappes
The other summer students
