LHAASO @ TeV 物理工作组会议

曹臻， IHEP，北京

泰达学院，塘沽， 2009

CRs at TeV

TeV γray astronomy

Ultra High Energy Cosmic Rays GZK cut-off related physics

“conventional” model

• Propagation effects• Fermi acceleration• Astro-accelerators?

Out line

• TeV γray astronomy (introduction)

• CR observational focus @ TeV region

• What can LHAASO contribute

• Status of the project

In our galaxy

All interesting objects

• PWN: Crab, Vela …

• SNR: RXJ1713, Cas A …

• XRB: Cygnus X-1, LS 5039

• ….

Models for γray emission• Electron origin model: synchrotron+IC• Synchrotron photons could be scattered again b

y electrons (SSC model)• Multi wavelength observation

lg10 (E/eV)

???

Hadronic model

ASCA data:

(synchrotron X rays)• Fine structures in the radiation

morphology points to B>100µG• If leptonic, X/TeV ratio requires

B~10µG (with IC/Sync B-2 )

Hadronic model favored

Difficulties:RXJ1713.7-3946 Leptonic model

Still pending: Hadronic model to be confirmed Occurence of such objects? (cf scan)

We are looking for good astro-accelerator lab in the sky

SN1006:γ ray observation still needs to be improved

The other example: PSR B1259-63• XRB: TeV emission occurs as the compact

object is far away from the Be Star?!

Could be an effect of absorption by photons from the B-star, however, is it really against the SSC model?

LSI+61 303 is Another example which does not Show difference Of spectral index

EarthEarth

LS I +61 303LS I +61 303

P~26.5 dayP~26.5 dayBH/NSBH/NS

Be StarBe Star

Radio OutburstsRadio Outburstsnear apastron,near apastron,

~4yr modulation~4yr modulation

High X-ray activityHigh X-ray activitythroughout orbit throughout orbit

(strongest at apastron,(strongest at apastron,secondary near secondary near

periastron)periastron)

TeV Activity detected TeV Activity detected by MAGIC/VERITAS by MAGIC/VERITAS around apastron around apastron

passagepassage

By Andy Smith at TeVPA 2009, SLAC

All Data 2006-2009All Data 2006-2009

Prel

imin

ary

Prel

imin

ary

Prel

imin

ary

Prel

imin

ary

Prelim

inary

Prelim

inary

1010σσ ~4.5~4.5σσ(pre-trial) (pre-trial)

ApastronApastron

Phases 0.9-0.5Phases 0.9-0.5Phases 0.5-0.9Phases 0.5-0.9

By Andy Smith at TeVPA 2009, SLAC

Almost isotropic and from z=0.0044(M87) to z=0.536(3c 279)

Many varying sources > 0.05ICrab at base states≥10 ICrab during flares

Very far sources:EBL absorption is severe above 10TeV

γastronomy: Mrk421flares

• 2006/7~8： 5.9σ• 2007： very calm• 2008/1~4： ~5.7σ

ASM of RXTE

2006/07-08

2006/09

2006/10

2006/09

2006/11

5.9σ

RXTE

ARGO

Mrk421single flare: 10ICrab

• ARGO has seen a 4σeffect

for 2008/05/02 transition.

Whipple

ARGO

2008 June 11-13day163-165

RXTE/ASM

Multi-wave-length Observation of Flares of Mrk421For LHAASO, only 1 minute is needed

Multi-wavelength observation:does SSC model work perfectly?

More sensitive observation with much larger exposureis essential in TeV regime

VERITASCollaboration

Mrk 501 Longterm Variability

There are many samples“Personality” seems very strong between transient events and objectsMany “guesses” with lacks of strong evidences. Strong demanding on population study: full sky survey！

Or some big pieces “dropped” into BH/NS and triggered an outburst??

TeV γRay Astronomy

• γRay Burst Search & Exotic phenomena– Yet successfully observed any GRB– Dark matter search– Quantum gravity effect search

Focus of CR observation @ TeV

• Knee and second knee

• Absolute energy scale at UHECR experiments

• Forward region behavior

• μ content in a shower

1017 eV Energy Spectrum: second knee: where is it? w

hy?

UHECR Research (experiment)

YBJ

access?

What can LHAASO help?

• All sky source survey

Scientific Problems and Possible Solutions

• TeVγray observation has an opportunity of finding CR origin: 80+ sources discovered– 50+ galactic sources: γat high energy (>30TeV) is crucial

(high sensitivity and high energy resolution)

– All-sky survey forγsource population is necessary

(full duty cycle, wide FOV and sufficient sensitivity)

• PeV CR spectra of individual composition– Bridge between space/balloon borne measurements and g

round based UHECR measurements

• Searching for Dark Matter galactic sub-structures

？

Hadronic model

Leptonic model

Large High Altitude Air Shower Observatory

Charge Particle

Arrayμdetector

Array

Water CArray

LHAASO Project: γastronomy and origin of CR

Wide FOVC-Telescope

Array&

Core DetectorArray

Forγastronomy

ARGO

？

Resolution for light and heavy composition

μ-content, Xmax and HE (>30TeV) shower particles

Proton Iron

For Proton and Helium:

1.5 m spacing

Nb>100 , any 5

(> 30 GeV)

For Iron:

3.75m spacing

Nb>100 , any 21

( > 30 GeV)

The keys are to lower threshold, making connections with direct measurements & measure spectra up to 100PeV

A bridge between balloon measurements and ground base UHECR experimentcovering both “knees” with absolute energy scale

An unique location

knee

Sec

ond

knee

We are here

Prototyping• R/D budget: ~$1M

• Detector unit prototype @ IHEP

On Site Prototype Exp.

• 1% of the final configuration of LHAASO

ARGO Hall

预先研究进展

• 1% 规模实验计划

From S. P. SWORDY, Space Science Reviews 99: 85–94, 2001.

CR Energy Spectrum

(160k events)

resolution < 10%With bias<3%Core resolution <1m

Conclusion• √s ~ 1TeV for CRs is a very important region ass

ociated with a transition from galactic origins to extra-galactic origins

• Elab~ 1TeV for γrays is one of the most active astro-particle physics fields. Many sources have been discovered in the last two decades

• LHAASO will boost all sky source survey power for population study, also have strong power for galactic CR source discovery

• Currently, the R/D for the project goes smoothly