tev gamma-ray astronomy and uhecr-1 trevor c. weekes, whipple observatory, harvard-smithsonian...

TeV Gamma-ray TeV Gamma-ray AstronomyAstronomy

and UHECR-1 and UHECR-1

Trevor C. Weekes,Trevor C. Weekes,

Whipple Observatory,Whipple Observatory,

Harvard-Smithsonian Center Harvard-Smithsonian Center for Astrophysicsfor Astrophysics

July 22-23, 2004July 22-23, 2004

Trevor Weekes Watson FestTrevor Weekes Watson Fest

OutlineOutline

Relevance to UHECR’sRelevance to UHECR’s Atmospheric Cherenkov Imaging Atmospheric Cherenkov Imaging

TechniqueTechniqueStatus of TeV ObservationsStatus of TeV Observations

Extragalactic TeV SourcesExtragalactic TeV Sources Observations of the UHECR SourcesObservations of the UHECR Sources

Next Generation TelescopesNext Generation Telescopes

July 22-23, 2004July 22-23, 2004


Relevance of TeV Astronomy Relevance of TeV Astronomy to Studies of UHE Cosmic to Studies of UHE Cosmic RaysRays Historical PrecedentHistorical Precedent Similar TechniquesSimilar Techniques Understanding of discrete Source (e.g. Understanding of discrete Source (e.g.

UHECR-1) demands study at other UHECR-1) demands study at other wavelengths; TeV Band is the Highest wavelengths; TeV Band is the Highest Energy Band in which Cosmic Sources have Energy Band in which Cosmic Sources have been reliably detectedbeen reliably detected

Existence of Extragalactic Sources of Existence of Extragalactic Sources of Relativistic Particles has been establishedRelativistic Particles has been established

New Generation of TeV Telescopes have the New Generation of TeV Telescopes have the sensitivity for detection of TeV component of sensitivity for detection of TeV component of UHECR sourcesUHECR sources

July 22-23, 2004July 22-23, 2004


Why study TeV Gamma Why study TeV Gamma rays?rays? Why do we study elephants when mosquitoes Why do we study elephants when mosquitoes

are easier to find and more plentiful?are easier to find and more plentiful?

TeV gamma-rays, like elephants, are bigger, more difficult to produce, and stretch the the production models to their limits!

July 22-23, 2004July 22-23, 2004


Simple Technique,Simple Detectors,Small Budgets

July 22-23, 2004July 22-23, 2004


Early Expectations of TeV Early Expectations of TeV Gamma-ray AstronomyGamma-ray Astronomy

We would find the Origin of the Cosmic We would find the Origin of the Cosmic RadiationRadiation

which would entail:which would entail:* Single source or class of sources* Single source or class of sources* Unambiguous detection of the 70 MeV * Unambiguous detection of the 70 MeV bump in the spectrumbump in the spectrum* Source(s) would be in the Galaxy* Source(s) would be in the Galaxy

In short: locate the “Smoking Gun” of In short: locate the “Smoking Gun” of Cosmic Ray Origins!Cosmic Ray Origins!

July 22-23, 2004July 22-23, 2004


Atmospheric Cherenkov ImagingAtmospheric Cherenkov Imaging

Cherenkov Imaging gives Cherenkov Imaging gives the ability to distinguish the ability to distinguish compact images of compact images of gamma-ray showers gamma-ray showers from more irregular from more irregular images from hadronic images from hadronic showersshowers

Arrival Directions also Arrival Directions also determined with high determined with high accuracyaccuracy

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Atm

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20 km

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To record the Cherenkov light images of gamma-ray initiated air showers, a large camera, consisting of an array of PMTs in the focal plane of a large optical reflector, is used.

July 22-23, 2004July 22-23, 2004


Hadron

Gamma

Gamma ray

Muon Ring Sky Noise

Types of images seen by atmosphericCherenkov camera

July 22-23, 2004July 22-23, 2004


The First TeV SourcesThe First TeV Sources

*Imaging systems came into operation 1984 -*First Galactic Source detected (Crab Nebula/Whipple Observatory) 1989*First Extragalactic Source detected (Mrk 421/Whipple Observatory) 1992

July 22-23, 2004July 22-23, 2004


Tev Gamma-ray Sky Status Tev Gamma-ray Sky Status c.2003c.2003

18 Sources reported in refereed literature; 10 are Extragalactic, 8 are Galactic

July 22-23, 2004July 22-23, 2004


Catalog NameCatalog Name SourceSource TypeType Date/GroupDate/Group EGREEGRET T

GradeGrade

TeV 0047-TeV 0047-25182518

NGC 253NGC 253 StarbursStarburstt

2003/CANG.2003/CANG. nono BB

TeV TeV 0219+42480219+4248

3C66A3C66A BlazarBlazar 1998/Crimea1998/Crimea yesyes C-C-

TeV TeV 0535+22000535+2200

Crab NebulaCrab Nebula SNRSNR 1989/1989/WhippleWhipple

yesyes AA

TeV 0834-TeV 0834-45004500

VelaVela SNRSNR 1997/CANG.1997/CANG. yesyes CC

TeV 1121-TeV 1121-60376037

Cen X-3Cen X-3 BinaryBinary 1999/1999/DurhamDurham

yesyes CC

TeV TeV 1104+38131104+3813

Mrk 421Mrk 421 BlazarBlazar 1992/1992/WhippleWhipple

yesyes AA

TeV TeV 1231+12241231+1224

M87M87 Radio Radio Gal.Gal.

2003/HEGRA2003/HEGRA nono CC

TeV TeV 1429+42401429+4240

H1426+428H1426+428 BlazarBlazar 2002/2002/WhippleWhipple

nono AA

TeV 1503-TeV 1503-41574157

SN1006SN1006 SNRSNR 1997/CANG.1997/CANG. nono BB

TeV TeV 1654+39461654+3946

Mrk 501Mrk 501 BlazarBlazar 1995/1995/WhippleWhipple

nono AA

TeV 1710-TeV 1710-22292229

PSR 1706-44PSR 1706-44 SNRSNR 1995/CANG.1995/CANG. nono AA

TeV 1712-TeV 1712-39323932

RXJ1713-39RXJ1713-39 SNRSNR 1999/CANG.1999/CANG. nono B+B+

TeV TeV 2000+65092000+6509

1ES1959+651ES1959+6500

BlazarBlazar 1999/TA1999/TA nono AA

TeV TeV 2032+41312032+4131

CygOB2?CygOB2? OB OB Assoc.Assoc.

2002/HEGRA2002/HEGRA nono CC

TeV 2159-TeV 2159-30143014

PKS2155-PKS2155-304304

BlazarBlazar 1999/1999/DurhamDurham

yesyes AA

TeV TeV 2203+42172203+4217

BL LacertaeBL Lacertae BlazarBlazar 2001/Crimea2001/Crimea yesyes CC

TeV TeV 2323+58492323+5849

Cas ACas A SNRSNR 1999/HEGRA1999/HEGRA nono BB

TeV TeV 2347+51422347+5142

1ES2344+511ES2344+5144

BlazarBlazar 1997/1997/WhippleWhipple

nono CC

July 22-23, 2004July 22-23, 2004


+ New Sources ~ + New Sources ~ 20042004 Galactic CenterGalactic Center PSR1259-63 at periastronPSR1259-63 at periastron Others? See following papers on Others? See following papers on

results from HESS and MAGICresults from HESS and MAGIC (also credibility of some southern (also credibility of some southern

sources has been questioned)sources has been questioned)

But no source (Galactic or Extragalactic) has yet been unambiguously identified as a source of Hadronic Cosmic Rays; all the TeV gamma rays could have Electron Progenitors.

July 22-23, 2004July 22-23, 2004


TeV Catalog of AGNTeV Catalog of AGNCatalog NameCatalog Name SourceSource Date/GroupDate/Group Type Type RedshiftRedshift

TeV 1104+3813TeV 1104+3813 Mrk 421Mrk 421 1992/Whipple1992/Whipple HBLHBL 0.0310.031

TeV 1429+4240TeV 1429+4240 H1426+428H1426+428 2002/Whipple2002/Whipple HBLHBL 0.1290.129

TeV 1654+3946TeV 1654+3946 Mrk 501Mrk 501 1995/Whipple1995/Whipple HBLHBL 0.0330.033

TeV 2000+6509TeV 2000+6509 1ES1959+6501ES1959+650 1999/TA1999/TA HBLHBL 0.0480.048

TeV 2159-3014TeV 2159-3014 PKS2155-304PKS2155-304 1999/Durham1999/Durham HBLHBL 0.1160.116

TeV 2347+5142TeV 2347+5142 1ES2344+5141ES2344+514 1997/Whipple1997/Whipple HBLHBL 0.0440.044

Horan, Weekes, 2003HBL = High frequency BL LacAll confirmed sourcesSpectra measuredLight-curves determinedMulti-wavelength CorrelationsOnly two in EGRET Catalog

July 22-23, 2004July 22-23, 2004


Time Variability: AGN Light CurvesTime Variability: AGN Light Curves

Variation in Nightly Rates from Markarian 421Whipple Observatory1995

Buckley et al. 1996

July 22-23, 2004July 22-23, 2004


Variations Seen on Many Time-Variations Seen on Many Time-scalesscales

Markarian 421Whipple ObservatoryHours - minutes

Markarian 501HEGRADays-months

July 22-23, 2004July 22-23, 2004


TeV Results: Correlations with X-TeV Results: Correlations with X-raysrays

July 22-23, 2004July 22-23, 2004


Mrk421 Spectral VariabilityMrk421 Spectral Variability

Power Law Cutoff Term

Exponent of Power Law Changes with Total Intensity.Cutoff Term Remains the Same

Krennrich et al. 2003

July 22-23, 2004July 22-23, 2004


Multiwavelength Results: Power Multiwavelength Results: Power SpectraSpectra

Synchrotron Compton

Mrk 501

Similar double peaked Power Spectra seen in other AGN

July 22-23, 2004July 22-23, 2004


AGN Jet Emission MechanismsAGN Jet Emission Mechanisms

Electron Progenitors:Electron Progenitors:Synchrotron Self Synchrotron Self ComptonComptonExternal ComptonExternal Compton

Proton Progenitors:Proton Progenitors:Proton CascadesProton CascadesProton SynchrotronProton Synchrotron

(Buckley, Science, 1998)

Cosmic Cannon:Looking down theBarrel of the Cannon

July 22-23, 2004July 22-23, 2004


Detection of Radio Galaxy, M87Detection of Radio Galaxy, M87

HEGRA Group4.1 sigma detectionWeak source but important

Nearby Radio Galaxy (Virgo A)

Off axis jet source

Aharonian et al. 2003

July 22-23, 2004July 22-23, 2004


Galactic Center: TeV SourceGalactic Center: TeV Source

Can

CANGAROO-III

E > 250 GeV

10% 0f Crab

Detection: strong

Steep spectrum: -4.6+/-0.5

Tsuchiya et al., ApJL (2004)

HESS Definitive results

See next talk!

Whipple 10 m telescopeObservations 1995-2003Southern SourceE > 2.5 TeV40 % of Crab3.7 sigmaKosack et al. ApJL (2004)

July 22-23, 2004July 22-23, 2004


TeV Gamma-ray Astronomy:TeV Gamma-ray Astronomy:A Legitimate New Astronomical A Legitimate New Astronomical DisciplineDiscipline

Essential Features of an Astronomical Essential Features of an Astronomical Discipline:Discipline: Location of SourcesLocation of Sources Measurement of Spectrum Measurement of Spectrum Time VariabilityTime Variability Correlation with other wavelengthsCorrelation with other wavelengths

Ready to be used to aid in the Exploration of UHECR Sources

July 22-23, 2004July 22-23, 2004


Study of Arrival Directions of Study of Arrival Directions of Ultra High Energy Cosmic Ultra High Energy Cosmic RaysRays UHECRs may be diffuse…or they may UHECRs may be diffuse…or they may

come from discrete sourcescome from discrete sources Since these must be nearby, they should Since these must be nearby, they should

be easily recognizable at long wavelengthsbe easily recognizable at long wavelengths If not, and if the production of UHECRs is If not, and if the production of UHECRs is

their unique property, they should still be their unique property, they should still be source of TeV gamma rays source of TeV gamma rays

Detection of coincident TeV source would Detection of coincident TeV source would confirm existence of UHECR source and confirm existence of UHECR source and give better locationgive better location

July 22-23, 2004July 22-23, 2004


Possible Sources of UHECR’s: Possible Sources of UHECR’s: New Challenge for TeV AstronomyNew Challenge for TeV Astronomy

Possible Clustering into discrete sources of 92 cosmic rays with E > 4 x 10^19 eV (results from AGASA, Havarah Park, Yakutsk, Volcano Ranch)

Marginally statistically significant correlation of Doublets and Triplets with Supergalactic Plane

Uchihori et al. 2000

July 22-23, 2004July 22-23, 2004


TeV Counterpart to UHECR TeV Counterpart to UHECR Source: Extragalactic CascadeSource: Extragalactic Cascade

Ferrigno, Blasi, Marco astro-ph/0404352

Electromagnetic Cascades initiated by photopion production of UHECR on extragalactic radio and microwave background may give detectable flux of TeV photons.

July 22-23, 2004July 22-23, 2004


Whipple Search for TeV Emission Whipple Search for TeV Emission in Error box of Fly’s Eye 3 x in Error box of Fly’s Eye 3 x 10^20 eV UHECR10^20 eV UHECR

Search made at 12 positions within the Error Box; no evidence for TeV emission

Akerlof et al. 2003

The Most ImportantDirection in theUniverse

July 22-23, 2004July 22-23, 2004


Akerlof et al. 2003

TeV maps from six of the twelve fields surveyed; no evidence of an excess.Field includes quasar 3C147 of historical interest….but too distant to be a candidate.

July 22-23, 2004July 22-23, 2004


Next GENERATION TELESCOPESNext GENERATION TELESCOPES

PhilosophyPhilosophy Improve Flux SensitivityImprove Flux Sensitivity Reduce Energy ThresholdReduce Energy Threshold Multiple > “10 m” telescopesMultiple > “10 m” telescopes New Technology where New Technology where

appropriate.appropriate.

Arrays of Imaging Telescopes

Now on line:CANGAROO III - 2004HESS - 2004

MAGIC - 2004 (VERITAS to come - 2006)

July 22-23, 2004July 22-23, 2004


World Picture of sub-TeV World Picture of sub-TeV ObservatoriesObservatoriesFour Major Observatories ideally distributed to give maximum Four Major Observatories ideally distributed to give maximum

coveragecoverage

CANGAROO III, 4 tel., 2004HESS, 4 tel., 2004

VERITAS,2004 1 tel. 2006 4 tel.

MAGIC, 1 tel., 2004 2 tel., 2006

July 22-23, 2004July 22-23, 2004


pp

Chicago Airport Display

July 22-23, 2004July 22-23, 2004


VERITASVERITAS

Four telescope system Four telescope system 12 m aperture12 m aperture 80m separation80m separation Filled triangle configurationFilled triangle configuration 499 pixel camera (0.15º/499 pixel camera (0.15º/pixel, 3.5º FOV)pixel, 3.5º FOV)

Kitt Peak, Tucson (32ºN, Kitt Peak, Tucson (32ºN, 36ºW, 1800m a.s.l.)36ºW, 1800m a.s.l.)

Current statusCurrent status Prototype telescope Prototype telescope

operating at Whipple operating at Whipple basecampbasecamp

FundedFunded Sources detected Sources detected VERITAS-4 in 2006VERITAS-4 in 2006

July 22-23, 2004July 22-23, 2004


1 GeV 100 GeV

GLAST (2 Years)

VERITAS-4(3 in 50 hrs)

Whipple 10 m (3 in 50 hrs)

July 22-23, 2004July 22-23, 2004


Prototype VERITAS Telescope

VERITAS Movie Cameras:

Advanced technology cameras;

500 Mhz FADCs

2 ns slices through shower images

(Leeds group has played major role in their design and construction)

July 22-23, 2004July 22-23, 2004


Typical Event: Typical Event: PrototypePrototype

July 22-23, 2004July 22-23, 2004


Results: Markarian 421Results: Markarian 421

Alpha<8 gives:

ON =1570 OFF=635.8

Sigma=19.9

Total Exposure=18.7 hours

Mean rate=0.83 gammas/min

July 22-23, 2004July 22-23, 2004


SummarySummaryNot one source but manyNot one source but many

Extragalactic Sources in profusionExtragalactic Sources in profusion

No Smoking Gun YET for Cosmic Ray Origins No Smoking Gun YET for Cosmic Ray Origins

A New Astronomical Discipline is EstablishedA New Astronomical Discipline is Established

Foundations are laid for Major Advances with next Foundations are laid for Major Advances with next Generation Systems working with auger, GLAST, Generation Systems working with auger, GLAST, icecube, etc.icecube, etc.

THESE MAY BE THE important PROBES OF UHECR THESE MAY BE THE important PROBES OF UHECR SOURCESSOURCES

July 22-23, 2004July 22-23, 2004


You have read the book: now watch the movie! (in 2 ns slices)

VERITAS Movie Camera

tev gamma-ray astronomy and uhecr-1 trevor c. weekes, whipple observatory, harvard-smithsonian...

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tev gammarays

cosmic sources

study tev gamma rays

uhecr sources observations

wavelengths tev band

class of sources

ray showers

compact images of gamma