A MultiTeV Survey of the Fermi Galactic Source Catalog Andrew Smith University of Maryland, College

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A Multi-TeV Survey of the Fermi Galactic Source
CatalogAndrew SmithUniversity of Maryland,
College Park

• Fermi Symposium
• Washington DC, Nov 2-5,2009

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Milagro Collaboration
A. Abdo, B. Allen, D. Berley, G. Christopher, T.
DeYoung, B.L. Dingus, R.W. Ellsworth, M.M.
Gonzalez, J.A. Goodman, C.M. Hoffman,P.
Huntemeyer, B. Kolterman, C.P. Lansdell, J.T.
Linnemann, J.E. McEnery, A.I. Mincer, P. Nemethy,
J. Pretz, J.M. Ryan, P.M. Saz Parkinson, A.
Shoup, G. Sinnis, A.J. Smith, G.W. Sullivan, D.A.
Williams, V. Vasileiou, G.B. Yodh
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Milagro Detector

• Central Water Pond (80x60 meter)
• 450 PMTs under 1.5 m water
• 273 PMTs under 6 m water
• Outriggers
• 2.4 meter diameter
• 1.4 meter tall
• 175 PMTs in outrigger tanks
• 2640 meters a.s.l. elevation
• 4000 m2 pond / 40000 m2 outrigger coverage
• 1700 Hz Trigger Rate
• 0.35o 1.0o angular resolution
• Sensitivity 100 GeV 100 TeV Median energy 10
  40 TeV (depending on cuts, weights etc)
• Operated from 2000-2008
• Operated2004-2008 with outriggers (2x
  sensitivity)

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Milagro Data
ApJ.664L91-L94,2007
Sensitivity of Gamma-Ray Instruments
1 TeV
100 TeV
1 GeV
Milagro
Fermi
VERITAS

• Since 2007, more data, improved analysis
• Comprehensive survey of the northern sky
• Comparable sensitivity (erg/cm2/s) to IACTs and
  Fermi only with a peak sensitivity at 100 TeV

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Fermi-LAT Bright Source List

• Sensitivity from 100 MeV to hundreds of GeV
• 205 gt10s sources in 3 months of data
• Blazars, pulsars identified by their variability.
• Several new pulsars (pulsations discovered in the
  GeV first)
• Angular resolution lt 0.1o

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Next Generation of Analysis - Energy

• Frasor variable F tracks energy
• Optimize weighting separately in each F bin.
• Excess in each F bin fit to MC to generate energy
  spectrum
• 1.5 years more data
• Crab 15.0s -gt 17.2s
• 15 - 25 cumulative increase in sensitivity
• Median energy 20 -gt 35 TeV

F
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Milagro Search for TeV emission from Galactic
sources

• 34 / 205 BSL sources are possibly Galactic and in
  Milagros field of view (d gt -5o)
• 16 pulsars
• 1 x-ray binary
• 5 SNR
• 12 unknown
• 14/34 are observed at 3s or more in Milagro data
• 6 of these 14 have been previously reported as
  sources or source candidates by Milagro and 2 by
  IACTs.
• 6 previously unreported sources are identified at
  gt3s.
• P(1gt3s) .04
• P(2gt3s) 6.7 x 10-4
• P(3gt3s) 7.8 x 10-6.....
• P(6gt3s) 2.2 x 10-12

• Most of the 3s sources are TeV detections, but
  cannot be claimed individually

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Abdo et al, ApJ Lett, 700, L127-L131 (2009)
gt8s VERITAS source adjacent (as of yesterday)
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(No Transcript)
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• Associated with IC443
• Molecular cloud
• TeV emission discovered by MAGIC, confirmed by
  VERITAS
• Milagro detects a 3.0s at the Fermi position.

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• Radio Pulsar J0631102
• Period288ms
• Age 43000yr
• Distance 6.55 kpc
• VERITAS upper limit 13mCrab
• Milagro detects a 3.7s excess

Indicates not previously reported
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• Most Significant source in BSL
• Old (300 kyr) and nearby (169 pc)
• 3.5s at the location of Geminga
• 6.3s when assuming 1o extended source
• Fitted FWHM 2.6o extent, consistent with IACT
  observations of more distant PWN

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• Unassociated with and known source.
• Very far south -gt very luminous at high energy.
• Milagro detects a 4.3s excess at the position of
  the Fermi source.

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• Associated with MGRO J190806, discovered by
  Milagro and confirmed by HESS and VERITAS (left)
• J1900.00356 has no know association (right)
• Milagro detects an excess of 7.4s and 3.6s
  respectively at the location of the Fermi sources.

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• Associated with SNR G49.2-0.7 (W51)
• HESS reported a detection coincident with this
  source.
• Milagro detects a 3.4s excess at the position of
  the Fermi source

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• Coincident with SNR G65.10.6 (left) and LAT
  pulsar PSR J19572831 (right)
• Milagro detects excess of significance 4.3s and
  4.0s respectively.

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• BSL source associated with previously reported
  MGRO J201937
• Most significant source in the Milagro data set
  apart from the crab.
• Young pulsar (17.2kyr) discovered by AGILE
• Milagro detects a 12.4s excess at the position of
  the Fermi source

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• J2021.54026 LAT discovered pulsar associated
  with gamma-Cygni SNR.
• J2032.24122 is a LAT discovered pulsar
  associated with HEGRA, Milagro and MAGIC TeV
  detections.
• Milagro observers excesses of 4.2s and 7.6s
  respectively at the positions of the Fermi
  sources.

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• Boomerang PWN, Also detected by VERITAS
• Associated with radio pulsar J22296114
• Milagro detects a 6.6s excess at the location of
  the Fermi source.
• Noted excess was very extended (4 deg)
• New Fermi pulsar (Science last Summer) located in
  the southern tail with 4.7s in Milagro data.

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Fermi Pulsar Catalog (astro-ph 0910.1608)
In Milagro FoV
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Pulsar Catalog Correlation
6 additional targets from PSR catalog
PSR J223859
High significance detections all have high
E/d2 J05322200 (17.2s), J22296114 (6.6s),
J20213651 (12.4s) But, some high E/d2 pulsars
are not observed J02056449 (-1.0s), J19523252
(0.0s) Similar correlation found in HESS PWN
(Carrigan, S., et al. 2007, in Proceedings of the
30th International Cosmic Ray Conference, Vol. 2,
659662) Mattana et al correlate X-ray and TeV
gamma-ray emission with better success.
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PSR J22296114
PSR J20213651
PSRJ05342200 -Crab
PSR J190706
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Conclusions

• Milagro was decommissioned in June 2008 and
  analysis of final dataset is nearly complete.
• List of sources and potential TeV emitters is
  growing. Appear to be mostly TeV PWN associated
  with MeV-GeV pulsars.
• Extended PWN with spectra extending past 10 TeV
  common to GeV pulsars.
• Evidence of spectral break if hard spectral index
  is assumed.