LHAASO @ TeV 物理工作组会议 曹臻，IHEP，北京 泰达学院，塘沽，2009

CRs at TeV Ultra High Energy Cosmic Rays GZK cut-off related physics TeV γray astronomy

“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 by electrons (SSC model) Multi wavelength observation ??? lg10 (E/eV)

Difficulties: RXJ1713.7-3946 ASCA data: (synchrotron X rays) Leptonic 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 sIC/sSync a B-2 ) Hadronic model favored Hadronic 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

LS I +61 303 Radio Outbursts near apastron, ~4yr modulation Be Star TeV Activity detected by MAGIC/VERITAS around apastron passage High X-ray activity throughout orbit (strongest at apastron, secondary near periastron) Be Star BH/NS P~26.5 day Earth By Andy Smith at TeVPA 2009, SLAC

All Data 2006-2009 Preliminary Apastron Preliminary Preliminary By Andy Smith at TeVPA 2009, SLAC Apastron Preliminary Phases 0.9-0.5 Phases 0.5-0.9 ~4.5σ(pre-trial) 10σ Preliminary Preliminary

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 5.9σ 2006/07-08 2006/09 2006/10 2006/11 2006/09 ASM of RXTE ARGO 2006/7~8：5.9σ 2007：very calm 2008/1~4：~5.7σ RXTE

Mrk421single flare: 10ICrab Whipple ARGO has seen a 4σeffect for 2008/05/02 transition.

Multi-wave-length Observation of Flares of Mrk421 For LHAASO, only ARGO RXTE/ASM 2008 June 11-13 day163-165 Multi-wave-length Observation of Flares of Mrk421 For LHAASO, only 1 minute is needed

Multi-wavelength observation: does SSC model work perfectly? More sensitive observation with much larger exposure is essential in TeV regime VERITAS Collaboration

Mrk 501 Longterm Variability

There are many samples “Personality” seems very strong between transient events and objects Many “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? why?

UHECR Research (experiment) access? YBJ

What can LHAASO help? All sky source survey

Scientific Problems and Possible Solutions Hadronic model Leptonic model ？ 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 ground based UHECR measurements Searching for Dark Matter galactic sub-structures

Large High Altitude Air Shower Observatory LHAASO Project: γastronomy and origin of CR Wide FOV C-Telescope Array & Core Detector μdetector Array Water C Array Charge Particle Array Large High Altitude Air Shower Observatory

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 experiment covering both “knees” with absolute energy scale

An unique location knee Second knee We are here

R/D budget: ~$1M Detector unit prototype @ IHEP Prototyping

On Site Prototype Exp. 1% of the final configuration of LHAASO ARGO Hall 1% of the final configuration of LHAASO

预先研究进展 1%规模实验计划

CR Energy Spectrum (160k events) resolution < 10% With bias<3% Core resolution <1m From S. P. SWORDY, Space Science Reviews 99: 85–94, 2001.

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