Marcos Lpez for the MAGIC Collaboration Univ. Complutense Madrid, - - PowerPoint PPT Presentation

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Marcos López for the MAGIC Collaboration

• Univ. Complutense Madrid, Spain, marcos@gae.ucm.es

ICRC 2017 – Busan

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The MAGIC telescopes

La Palma island MAGIC site Performance

• Energy range: 50 GeV to 50 TeV
• Sensitivity: 10% Crab in 1 h above 100 GeV
• Energy resolution: 15 – 23%
• Angular resolution: ∼0.1º

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Characteristics

• 2 Imaging Atmospheric Cherenkov Telescopes
• 17 m diameter with active mirror control
• Fast readout ∼2 GS/s
• ∼ 2TB per night

MAGIC continuous improvement

• 4x improvement sensitivity over last decade
• 10x at the lowest energies !

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MAGIC has made significant contributions to the study of galactic sources

MAGIC Galactic Physics Program

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Discovery of the first VHE pulsar Pulsars Search for Pevatrons SNRs Periodic emission from binary systems Bianry systems

Search for Microqusars

Mapping de Galactic Center

Fundamental Physics

Study of LIV Crab nebula over 4 decades PWN

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MAGIC

• 2008: Crab pulsar above 25 GeV
• Rule out low altitude models
• 2012: Spectrum measured up to 400 GeV
• Spectra follow power-laws

➔ No cutoff seen

Before MAGIC

• Different 𝜹-ray emission sites

proposed for Crab:

• Emission via curvature radiation
• Expected sharp exp. cut-offs at

few GeV

Pulsars at TeVs

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Pulsars

Where do 𝜹-rays come from?

New models proposed

• Within or beyond the magnetosphere
• If beyond, expected cutoff at ~0.5 TeV

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Pulsars at TeVs

MAGIC latest Crab results

• MAGIC detected TeV emission from Crab
• Used 8 years of data, 320 hours
• Spectra of both peaks extending as power-

laws far beyond the expected cutoffs:

• P1 detected up to 0.6 TeV (𝛥=3.5 ± 0.1 )
• P2 detected up to 1.5 TeV (𝛥=3.0 ± 0.1)

Implications of TeV emission

• Synchrotron-curvature ruled out

➔ Most likely, emission from outer magnetosphere via IC

• But no model can fully explain TeV

pulsations

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Pulsars

Up to which energy does the Crab pulsate?

MAGIC E > 400 GeV

Energy [GeV]

• 1

10 1 10

2

10

3

10

]

• 1

s

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[TeV cm dEdAdt dN

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E

• 15

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• 14

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• 10

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Fermi-LAT P1 Fermi-LAT P2 MAGIC P1 MAGIC P2 Phase

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

• 50

50 100 150 E > 400 GeV

Ansoldi et al., A&A 582 A133 (2016)

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arXiv:1707.01583 / D. Guberman ICRC2017

MAGIC latest results

• 160 h of data (2014 and 2016)
• SED measured up to 8 TeV
• Exponential cut-off (EPWL) fit preferred
• ver pure power-law (PWL) at 4.6𝝉
• Cut-off at ~ 3.5 TeV
• Even if TeV due solely to hadrons, Cas A

cannot be a PeVatron at present time

Cas A is not a Pevatron!

Context

• SNRs considered the most promising source of CRs up to the “Knee”.
• But no evidence (yet) of particle acceleration up to 1015 eV

Cassiopeia A (Cas A)

• Bright and point-like in GeV/TeV (HEGRA, VERITAS, MAGIC and Fermi)
• Considered a classical Pevatron candidate

SNRs

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Context

• Binary system: Be star + unknown compact
• bject (orbital period 26.5 days)
• Discovered at VHE by MAGIC in 2006
• Orbital variability: TeV emission only when

compact object is far from the stellar disc

• Modulation at longer time scales?

Latest results

• Extended campaign by MAGIC & VERITAS in

2010-14, added to archive data since 2006

• Superorbital 4.5 yr variability found at TeV !
• Period consistent with optical, radio and HE

Super-orbital Variability of LSI+61 303

Binaries Possible superorbital explanation Flip-flop magnetar scenario (Torres et al. 2012):

Expected antcorrelation between Size of the disk and VHE emission

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A&A 591, A76 (2016) / D. Hadash, ICRC 2017

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• Acceleration in microqusars jets may produce TeV, but not (yet) detected
• MAGIC has deeply studied 2 high-mass microquasars: Cygnus X-1 and X-3

Galactic jets at TeV?

Cygnus X-1

• A recent analysis of ~8 yrs of Fermi-LAT

shows detection up to 20 GeV

• MAGIC observed 100 h during 2007-2014

➔ No detection above 200 GeV

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Cygnus X-3

• Detected in 2009 by Fermi during a flare
• In 2016, flaring in radio and GeV
• MAGIC follow-up observations for 70 hr

➔No detection at TeV

VHE flux is suppressed ➔ no efficient acceleration on the jets

See also A. Fernández-Barral @ ICRC 2017 MAGIC Coll., submitted to MNRAS (2017)

Binaries

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Galactic Center

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Ahnen et al., A&A, 601 (2017) A33 2013 2014 2015 Gas Cloud Sgr A*

ESO simulation

Flux > 1 TeV 10x Flux > 10 TeV

• In 2012 found a gas cloud (~3 Earth masses) orbiting towards the SMBH Sgr A*
• MAGIC observed 70 h (2012-15) the GC

Light curve

• No TeV variability found during the

passage of the gas cloud

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E [GeV]

2 −

10

1 −

10 1 10

2

10

3

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4

10

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]

• 1

s

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[TeV cm dE dA dt dN

2

E

14 −

10

13 −

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12 −

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11 −

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10 −

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Fermi, Malyshev et al. 2015 MAGIC, this work 0.1 deg (Schmelling) MAGIC, this work 0.1 deg (Forward)

• Had. model, Chernyakova et al. 2011
• Had. model, Ballantyne et al. 2011
• Had. model, Linden et al. 2012
• Had. model, Fatuzzo et al. 2012

Hybrid model, Guo et al. 2012

• Lept. model, Kusunose et al. 2012
• Syst. err. MAGIC

Galactic Center

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Spectrum of Sgr A*: 0.3 - 50 TeV

• Power-law with an exp. cutoff at 7.6 TeV
• Matches nicely Fermi spectrum
• Compatible with leptonic or hadronic models

Ahnen et al., A&A, 601 (2017) A33

SgrA* & G0.9 removed

Morphology

• Detected Sgr A* and G0.9+ 0.1
• Removing foreground ➔ Discovered new

VHE source in the radio Arc region: MAGIC J1746.4-2853

Sgr A* G0.9 Arc Sgr A* G0.9 Arc

• In 2012 found a gas cloud (~3 Earth masses) orbiting towards the SMBH Sgr A*
• MAGIC observed 70 h (2012-15) the GC

Light curve

• No TeV variability found during the

passage of the gas cloud

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Follow-up of HAWC sources

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Unidentified HAWC sources

• The 2nd HAWC catalogue (2017) contains 39 detected TeV sources.
• 19 of them have no association with any known VHE source

HAWC source Tobs [h]

2HWC J2006+341 61 2HWC J1907+084 4 2HWC J1852+013 120

• Re-analysis of these MAGIC observations looking for point-like emission (0.10º)
• r slightly extended (0.16º)

➔ No signal found MAGIC archive data

• Some of these 19 Unid. sources were in the FoV (<1.5º) of former MAGIC
• bservations:

Preliminary

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MAGIC welcomes observational proposals by external scientists: Looking forward to do great science together !

MAGIC opening to external scientists

https://magic.mpp.mpg.de/outsiders/magicop/

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• Starting from this year,

external scientists can apply for MAGIC

• bservation time
• Deadline for the call:

03-Nov-2017

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Outstanding recent MAGIC galactic results:

• Crab pulsation up to TeV
• Cas A is not a Pevatron
• Superorbital TeV modulation in LS I+61
• Deep observations of microquasars ➔ No detections so far
• 4 year observations of Galactic Center ➔ Detection of a source in the Arc region
• Follow-up studies of Unid. HAWC sources ➔ No counterpart found

Summary

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For more details, see the 7 dedicated MAGIC galactic contributions @ ICRC 2017:

• A. Fernández-Barral:

Pulsar Wind Nebulae

• D. Guberman:

Cassiopeia A

• D. Hadash:

Binary Systems

• A. Fernández-Barral: Cygnus X-1 & Cygnus X-3
• M. Strzys:

Gamma-Cygni

• M. López:

Black Widow B1957+20 binary system

• M. Gaug:

Lorentz invariance violations using the Crab pulsar

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BACKUP

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PSR B1957+20:P2

Energy [GeV]

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10 1 10

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dN/dE [TeV cm

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MAGIC UL FERMI =1.45 Ec=1.8 b=1.0 Γ PLExpCutoff: =2.23 Γ PL: MAGIC UL FERMI =1.45 Ec=1.8 b=1.0 Γ PLExpCutoff: =2.23 Γ PL: MAGIC UL FERMI =1.45 Ec=1.8 b=1.0 Γ PLExpCutoff: =2.23 Γ PL:

PSR B1957+20:P2

Pulsar searches

Geminga

• After Crab, it is the brighter Fermi

pulsar in the Northern Sky

• VHE emission tail?
• Observed by MAGIC for 60 h
• No signal detected above 50 GeV.
• Upper limits don’t allow to rule out the

existence of a VHE power-law tail.

Pulsars

MAGIC Geminga P2

Ahnen et al., A&A 591 A138 (2016)

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Black widow B1957+20 ms pulsar

• MS pulsars orbiting low massive stars

could produce VHE emission

• But not (yet) detected
• MAGIC observed the system for 66 h
• 4 possible regions in which 𝜹-rays could be

produced

• No emission detected in any case

Region Expected emission

• I. Bow shock

Extended / steady

• II. Inner nebula

Point-like / steady

• III. Binary system

Point-like / modulated

• IV. Pulsar

Point-like / pulsed

Pulsar phase

• 0.2
• 0.1

0.1 0.2 0.3 0.4 0.5 0.6 0.7 Events 340 360 380 400 420 440 460

MAGIC > 50 GeV

P2

Ahnen et al., arXiv:1706.01378

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• A. Fernández-Barral, ICRC 2017

Latest MAGIC observations

• MAGIC has observed 3 promising PWN

candidates around high spin-down power Fermi pulsars

• No signal found from any candidate.
• MAGIC results are in agreement with the

expected luminosity in the 1-10 TeV band.

• PWNe are the most numerous population of TeV sources in our galaxy:
• Powered by young and energetic pulsars ➔ Particles accelerated to VHE in

the pulsar surroundings, or at the shocks

• MAGIC detected the less luminous (3C 58) and the most luminous ones (Crab)

Pulsar Wind Nebulae searches

16 Pulsar Campaign Tobs [h] PSR J0631+1036 2015/16, 2016/17 37 PSR J1954+2838 2015 16 PSR J1958+2845 2015 4

The band shows the fit obtained from detected PWNe and ULs in HESS galactic survey

PWN

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Galactic jets at TeV?

Binaries

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V404 Cygni

• Low-mass X-ray binary: BH and K3 III star,
• rbital period: 6.5 days
• Quiescent since 1989

MAGIC observations during June 2015 exceptional flares

• Series of outbursts in hard X-rays (flux

reached 50 Crabs)

• One of these X-ray flares coincident with a

giant radio flare and a 4σ hint by Fermi-LAT

• MAGIC triggered by the INTEGRAL
• Observed 10h in several nights
• Non-detection by MAGIC
• Inefficient particle acceleration inside

the jets or not enough energetics of the VHE emitter.

• MAGIC has studied also low-mass microquasars
• INTEGRAL

FERMI-LAT hint

MAGIC time bins

arXiv:1707.00887 / Accepted by MNRAS

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• New trigger system installed in MAGIC telescopes,

to reduce the energy threshold and improve the performance for pulsars:

• Trigger threshold ~30 GeV

Phase 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 Events 650 700 750 800 850 900

T

• bs = 10.2 [h]

7.2 σ

Outlook: New stereo SumTrigger

• This should allow MAGIC to detect additional VHE pulsars in the Northern Sky

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• Test Crab pulsar data shows that new trigger system outperforms the standard
• ne.
• M. López (EWASS 2016)