44th Rencontres de Moriond - La Thuile, Valle d’Aosta, February 1-8, 2009

The MAGICThe MAGIC extragalactic extragalactic skysky

Barbara De LottoBarbara De LottoUniversitUniversità di Udine & INFN - Italyà di Udine & INFN - Italy

on behalf ot the MAGIC Collaborationon behalf ot the MAGIC Collaboration

The telescope MWL campaigns

Recent results & discoveries Hints of new physics?

Imaging Air Cherenkov Imaging Air Cherenkov TechniqueTechnique

~ 10 kmParticleshower

~ 1o

Ch

eren

kov

ligh

t

~ 120 m

Gammaray

Cherenkov light Image of particle shower in telescope camera

- reconstruct: arrival direction, energy- reject hadron background statistically in the analysis

The MAGIC siteThe MAGIC site

La Palma, IAC28° North, 18°West

~2240 m asl

• Currently the largest single-dish Cherenkov telescope (17 m diameter)

• In operation since fall 2004 ( starting AO-5 in Spring ’09)

• Sensitivity: 1.6% Crab in 50 h

• Angular resolution: 0.1 deg

• Energy resolution: ~ 20%

• Enhanced duty cycle (by 50%) thanks to moonlight & twilight observations

• Substantially lower energy threshold than other installations:

• 55 GeV nominal

• 25 GeV pulsar (“sum”) trigger

• Fast repositioning (~30 s)

• 2nd telescope (MAGIC-II) first light this winter, ceremony on April 24th

The MAGIC The MAGIC telescopetelescope

~150 physicists, 23 institutesGermany, Italy, Spain leading

Propagation of Propagation of -rays-raysx

xx

Measured spectrum affected by attenuation in the EBL:

For rays, relevant background component is optical/infrared (EBL) different models for EBL: minimum density given by cosmology/star formation

Measurement of spectral features permits to constrain EBL models

Science 2008

≈

~ E-2

VHEEBL e+e-

dominant process for the absorption:

maximal for:

Heitler 1960

() ~

Attenuation of Attenuation of -rays-rays

),( zEoe

-ray horizon:-ray horizon:

(E,z) = 1(E,z) = 1

Importance of decreasing the energy threshold to look further away

Blanch & Martinez 2005

region of opacity:

> 1

optical depth

Fazio & Stecker 1970

Extragalactic VHE Extragalactic VHE -ray -ray sourcessources

24 AGN discovered by IACTs:

Ref.:

Extragalactic VHEExtragalactic VHE-ray sources:-ray sources:23 blazars & 1 radio galaxy23 blazars & 1 radio galaxy

AGN with relativistic jet aligned with observer’s line of sight of observer

non-thermal emission, highly variable

Blazars:

observerobserver

AGNs: sources of extragalactic CRs?VHE -rays: leptonic or hadronic origin?

E2 d

F/d

E

energy E

0decay

IC

shape of spectrum

Extragalactic Background Light Propagation mechanisms Lorentz Invariance

e- (TeV) Synchrotron (eV-keV)

(TeV) Inverse Compton (eV)

B

leptonic acceleration

-

0

+

(TeV)

p+ (>>TeV)

matter

hadronic acceleration

Highlights in Highlights in MAGICMAGIC extragalactic observationsextragalactic observations

Mrk421 (z=0.031) 1ES2344 (z=0.044)

1ES1959 (z=0.047)

Mrk501 (z=0.034) Mrk180 (z=0.045)

MAGIC discovery

1ES1218 (z=0.18)

MAGIC discovery

+ 3 more in press …

M87 (z=0.0043)

S5 0716 (z=0.31)

BL-Lacertae (z=0.069)

MAGIC discovery

1ES1011 (z=0.212)

MAGIC discovery

3C279 (z=0.536)

MAGIC discovery

MAGIC J0223(3C66B?)

MAGIC discovery

PG 1553+113 (z>0.25)

MAGIC codiscovery

MAGIC disc

overy

PRELIMINARY

Bright Blazars Multiwavelength Bright Blazars Multiwavelength campaignscampaigns

•Simultaneous Multifrequency Observations covering •15 decades in photon energy:

VHE: H.E.S.S., MAGIC, VERITASHE: Agile, FermiX-ray: Suzaku, Swift, Chandra,

IntegralOptical: KVARadio: Metsahövi, …

•

Some recent MWL campaigns: •Mrk 421, Mrk 501, PG 1553+113, 1ES 1218+304, 1H 1426+428, M87

•Further under process, organized …

1ES 1959+650 1ES 1959+650 ApJ 679 (2008) 1029ApJ 679 (2008) 1029

MWL campaign during May 2006 with Suzaku and Swift Two-peaked SED VHE emission (E>200 GeV) at one of the lowest ever observed states,

no significant variability detected Modeled by a one-zone SSC model

Mrk 421 June ‘08 Mrk 421 June ‘08 flareflare

Donnarumma+ ApJ 691 (2009) L13 ApJ 691 (2009) L13

Hard X-ray flare triggered MWL campaign:WEBT, Swift, Agile, MAGIC, VERITAS

Time variability in TeV and X-ray comparable

SSC modeling

Interpretation paper under development

PG 1553+113PG 1553+113

MWL campaign during July 2006 with H.E.S.S., Suzaku and KVA

Simultaneous MWL campaign during March-April 2008 with Agile, XTE/ASM and KVA

[paper in preparation]

Differential spectrum compatible with H.E.S.S. and previous measurements

Reimer+ ApJ 682 (2008)

A&A 493 (2009)

Spectral Energy Distributiom:homogeneous one-zone SSC model

PRELIMINARY

KVA

AGILE

U.L. MAGIC

XTE/ASM

M87M87

constant flux

>350 GeV

150-350 GeV

day-scale : 5.6 σ

α=–2.2

α=–2.6

(Crab nebula)

• VERITAS/MAGIC/H.E.S.S. monitoring

• 8 on 2008 Feb 1 → Trigger issued to VERITAS and H.E.S.S.

• 9.9 in overall sample (22.8 hours) between 2008 Jan 30-Feb 11

• Flux variable between 3-15% Crab

• High variability > 350 GeV

• Confirming day-scale variability (5.6). No intra-night variability

• Compatible with constant between 150-350 GeV

ApJ Lett. 685 (2008) L23

The first non-blazar radio galaxy observed to emit VHE -rays

Optical triggers Optical triggers new discoveries new discoveries

Mkn 180z = 0.045

ToO trigger

MAGIC12.1 hS=5.5 σ

March 2006

ToO trigger 1ES 1011+496 z = 0.212

MAGIC 18.7hS=6.2 σ

March-May 07ApJ, 667 (2007) L21

S5 0716+714MAGIC PRELIMINARY

Significance 6.8 σ

S5 0716+714 z = 0.31

KVA optical telescope at la Palma

ApJ, 648 (2006) L105

The 3C 66A/B regionThe 3C 66A/B region B: radio Galaxy A: distant Blazar, VHE candidate (EGRET, Crimea, VERITAS, Fermi) MAGIC observations triggered by optical outburst in 2007

ApJ Lett. 692 (2009) 29

3C 66B is more likely the source of emission (MAGIC J0223+430)

• flat-spectrum radio-quasar at z=0.536

• brightest EGRET source. Highly variable, fast variability (~6 hours)

• MAGIC observed it in 2006 during WEBT campaign for 9.7 hours in 10 nights

• Clear detection 23rd Feb 2006 (6.2)

First FSRQ in TeV -rays

Major jump in redshift

3C279 3C279 the most the most distantdistant Science 320 (2008) 1752

skymap

Energy spectrum of Energy spectrum of 3C2793C279

Measured and EBL-corrected spectrum:

3C279 and the 3C279 and the -ray -ray horizonhorizon

Test of the transparency of the universe extended to z = 0.536!

Is there a new land just behind the horizon?

Spectral characteristics of observed Spectral characteristics of observed AGNAGN

ob

serv

ed

sp

ect

ral

ind

ex

redshift

Selection bias? New physics?

adapted from De Angelis, Mansutti, Persic, Roncadelli MNRAS 2009

Limits on 3C454.3Limits on 3C454.3

We have also searched farther out: during summer 2007 intense emission of

3C454.3 - a well known FSRQ @ z = 0.86 - detected by AGILE

Upper limits derived fromMAGIC data together with nearly simultaneousmultifrequency dataallow to constrain the SED

Quantification of the delay:

(0.030±0.012) s/GeV

Probability of no delay: 2.6%

Possible explanations:

• Astrophysical: intrinsic source effects

photons at different energies were

emitted simultaneously

• Propagation effect due to Lorentz invariance violation:

Probing the Planck energy scale

ApJ 669 (2007) 892 Phys Lett B 668 (2008) 253

Energy-delayed flare of Energy-delayed flare of Mrk501:Mrk501:

IF

2

' 1 ss E

E

E

Ecc

Flares: a way to new physics?

150-250 GeV

250-600 GeV

600-1200 GeV

> 1200 GeV

July 9 ‘05July 9 ‘05

Opens the way to future population AGN studies at different z

MAGIC is producing high quality astrophysics after ~3.5 MAGIC is producing high quality astrophysics after ~3.5 observation cycles:observation cycles:

Lowest energy threshold => deepest horizon Lowest energy threshold => deepest horizon We have discovered 8 new extragalactic sources, We have discovered 8 new extragalactic sources,

detected and studied 5 knowndetected and studied 5 known Important contributions to the understanding of AGN, EBLImportant contributions to the understanding of AGN, EBL Now reaching out much further in redshift: high energy Now reaching out much further in redshift: high energy

photons (often traveling through large distances) are a photons (often traveling through large distances) are a powerful probe of fundamental physics under extreme powerful probe of fundamental physics under extreme conditions conditions

MAGIC-II starts operations on April 24MAGIC-II starts operations on April 24thth

CONCLUSIONSCONCLUSIONS

BACKUP

Optical depth