TA Recent Results and Prospects
ISVHECRI-2014
CERN, Geneva
2014/08/19
Masaki Fukushima for Pierre Sokolsky
and the TA Collaboration
Telescope Array Collaboration
3
Ýêñïåðèìåíòû ïî ÊËÑÂÝ (E & 1018 ýÂ)
Yakutsk array
Pierre Auger
Telescope Array
Ã.È. Ðóáöîâ, È.È. Òêà÷åâ
Ñòàòóñ è ðåçóëüòàòû TA è Auger
3
UHE Cosmic Ray Spectrum
SD Data (6 Yrs: 20080511-20140511, 5400 km2 str yr)
Broken Power Law Fit
γ 1 = -3.298 +/- 0.029
γ 2 = -2.673 +/- 0.028
Log(E_GZK/eV) = 19.74 +/- 0.038
γ 3 = -4.539 +/- 0.441
Significance of GZK Effect:
Integrate log10(E/eV) = 19.8 to 21.0
Nexp = 85.9
Nobs = 32
GZK Chance Prob = 2.248e-11 = 6.59σ
Berezinsky E1/2::
Log(E/eV) = 19.73 +/- 0.042
Break significance = 6.59σ
12
CR Spectrum
SD Data (6 Yrs: 20080511-20140511)
Comparison with HiRes-I and HiRes-2
13
Fitting TA Spectrum with extra-Galactic Proton
Energy Loss with
• CMB
• Infra-Red
using CRPropa 2.0 checked with
transport eq.
(Kalachev+Kido, arXiv:1406.0735)
Source Distribution
• Uniform
• LSS (~2MASS XSCz)
up to 250 Mpc
• No magnetic field
4-parameter fit
• Injection spectrum : E -p
Emax = 1021 eV
• Evolution : (1+z)m
• Flux normalization
• Energy scale
Preliminary
Uniform : χ2/ NDF = 21.3 / 17
p = 2.2 and m = 6.4
CR Spectrum
SD Data (6 Yrs: 20080511-20140511)
Comparison with Auger: ICRC 2013 + 10%
14
¨
¨
¨
¨
¨
SD and FD energy
estimations disagree
FD estimate possesses
less model-dependence
Set SD energy scale to FD
energy scale using wellreconstructed events
from all 3 FD detectors
27% renormalization.
21% systematic
uncertainty in FD energy
scale
5 August 2014
COSPAR 2014
26
Xmax Technique
•
•
•
Shower longitudinal development
depends on primary particle type.
FD observes shower development
directly.
Xmax is the most efficient
parameter for determining
primary particle type.
PRL.104.161101
(2010)
HiRes
Number of charged particle
Shower longitudinal development
Xmax
Depth [g/cm2]
PRL.104.091101
(2010)
Auger
FD stereo Xmax
FD
Stereo
Xmax
• FD stereo 5-year data (Nov., 2007 – Nov. 2011)
preliminary
Both Data
& MC
•Blue:
Data: Iron
TA (QGSJET-II-03)
Y.Tameda
of
ICRC2013
•Red:
Red histogram:
QGSJET-II-03 protonBlack:
modelDatawith bias
Proton (QGSJET-II-03)
. Reconstruction
• Blue histogram: QGSJET-II-03 iron model
. Cut
2013/12/21
The TA data is consistent with QGSJET-II-03 proton prediction.
The TA data (stereo) is consistent with
QGSJET-II-03 proton prediction.
14
8
High Energy Hybrid Event
Energy: 1.282
1020 eV
Zenith Angle: 55.7°
Surface array constrains
geometry fit via extra timing
& core information
17
Xmax in Energy Slices
Comparison to p/Fe MC
18.2 < Log10(E/eV) < 18.4
18.4 < Log10(E/eV) < 18.6
18.6 < Log10(E/eV) < 18.8
18.8 < Log10(E/eV) < 19.0
Xmax in Energy Slices
Comparison to p/Fe MC
Log10(E/eV) > 19.0
Results are consistent with proton at all
energies and inconsistent with iron.
KS Test
• 472 AGN from 2006 Veron catalog with z < 0.018
P. Tiynakov
• E > 57 EeV, zenith angle < 45o, N = 42 (5 yr)
ICRC2013
Correlation
with
AGNs
• Separation angle = 3.1o
TA events:
correlated
not correlated
AGN
Anisotropy (Nearby AGN)
AGNs are from VCV 2006 catalog, cut by z (0 ＜ z ≦ 0.18).
There are 465 AGN in our field of view.
Primary Energy ＞ 57EeV, Angular Separation ＜ 3.1°.
• Probability to hit AGN with a single event po = 0.24
v  42•UHECR
events correlate out of 42 (0.40)
17 events
p = 1.4%
(>57EeV, θ<45°, 5 years)
v  472
AGNs from VCV catalog
2013/12/21
v  Separation angle : 3.1°
18
v  17 events correlate out of 42
à Chance probability p=1.4%
17 events correlate out of 42 events.
12
This probability is 0.014 from chance correlation.
2130 events
P. Tinyakov, ICRC2013
TA Skyplots
132 events
52 events
Correlation
with
LSS
Composition measured by TA
Anisotropy
(LSS)
Anisotropy (LSS)
P. Tiynakov
ICRC2013
Composition measured by TA
is consistent
with with
proton.
is consistent
proton.
v  Large-Scale Structure model
2MASS Galaxy catalog (XSCz)
Protons
Data form
(white
point)
Datasources
(white
point)
and Model
distribution
and Model
distribution
v
Grey
Pattern:
Model
with
(shaded
region)
(shaded
region)
from from
LSS LSS
TA exposure
at 6°100Mpc.
smearing angle
within
within
100Mpc.
v  White points: >57 EeV TA data
v  Our When
data deflection
is consistentangle
with θ
When
deflection
angle
θ
the LSS
model
~10%
set
to 6°,
p-value of
In alltosmearing
angles.
set
6°, p-value
of .
isotropy
is 0.001
isotropy is 0.001 .
v  Consistency with isotropy
at 6° smearing angle
Is ~0.1% level.
Compare with the LSS
Smearing angle
13
• Hotspot center R.A.=146.7o, Dec. = 43.2o (max. 5.1σ)
• Chance probability from Isotropic sky : 3.7 x 10-4 (3.4 σ)
i.e. 5.1σ enhancement anywhere in TA’s FoV & any size r=15, 20,… 35o.
Event Distribution New 1 year
New 1-year data : 15 events
39
5+1 year data
5 August 2014
Events with E > 57 EeV
COSPAR 2014
20
¨
¨
¨
¨
¨
¨
72 events (5 years) + 15 events (6th year) total with
E > 57 EeV
19 events (5 years) + 4 events (6th year) in hotspot
5.1σ Li-Ma significance goes to 5.55σ
3.4σ (with sampling penalty) goes to 4.0σ
For 6th year only, 4/15 events in previous hotspot:
7% probability
The hotspot is getting hotter!
5 August 2014
COSPAR 2014
22
TAx4 Proposal
TA High Energy Extension (TAx4)
Basically it uses same method as TA, with a FD and 3 times larger
coverage area by SDs. SD full area can not be covered by FD field of
view.
²  Now there is hint of anisotropy
at 3σ level
forexperiment
northern sky.
This
is mainly
for anisotropy study,
v  Plan to expand
4 times
This is TA
forby
detecting
2
more cosmic (3,000km
rays which)
1. Add 500
scint.
counters
have
energy
over GZK. If
withare
2.1 proton,
km spacing
they
their
2. 10 refurbished
HiRes
tels 50Mpc.
source is
within
From our current result
the inconsistency
v  Scienceof(3-year
observation)with
isotropy at high energy
we are halfway to
1. Study ofregion,
anisotropy
a clue?
à catching
Expect 5σ
2. Xmax at highest energy region
3. UHE photon
& neutrino
search
Now, proposing
construction.
18
TALE SDs
pes
35 TALE SDs were deployed among 101 SDs.
TALE
Low-E Extension)
TALE
(TA(TA
Low-energy
Extension)
16.5 eV
down
to
10
v  Target
range
10 -10
eV
TALE
(TA
Low-energy
Extension)
- Second Knee
16 SDs in operation
16.5
10 TALE FDs:
ICRC2013
refurbished HiRes-II telescopes
Oral, 717
installed and running.
19
• E = 1016.5 – 1019 eV
• ~1017 eV cosmic ray shower:
TALE SDs with LHC center-ofcompatible
mass energy
35 TALE SDs were deployed among 101 SDs.
- Change of mass composition
• Second
10 TALE
FDs: knee at ~1017.5 eV?
- LHC center of mass E
•refurbished
Drastic change
oftelescopes
composition
HiRes-II
17
18
v
TALE
is
operating
partly
now
eV?
at
10 ~10
Observed hybrid
events
installed
and running.
16 SDsTALE
in operation
layout
TA FD/TALE FD
• Transition from galactic to
extra-galactic cosmic rays?
Observed
?
FD data
TALE FD events (data)
SD data
Observed hybrid events
TALE FD ev
25
101 TALE SDs
2013/12/21
2013/12/21
FD data
TALE FD events (data)
SD data
24
19
CR Spectrum
SD Data (6 Yrs: 20080511-20140511)
+ high elevation TALE telescopes (no MD so far)
and events with large Cerenkov contribution
Very Early TALE Data
54
SPECTRUM: from Knee to Cutoff
Akeno
Akeno
Tibet
Tibet
KASCADE-G KASCADE-G
Tunka
Tunka
IceTop
TA
Akeno
KASCADE-G
Tunka
IceTop
TA
FY stereo
HiRes-MIA
Auger
TA
AGASA
FY stereo
HiRes-1+2
HiRes stereo
Auger
TA
HiRes-1
HiRes stereo
1
SPECTRUM: from Knee to Cutoff
¨
¨
¨
TA sees evidence for anisotropy in the Northern
Hemisphere
TA has observed the GZK Cutoff and extended the
spectrum energy down to 1016 eV with 4 spectral
features
TA observes a proton-like composition
5 August 2014
COSPAR 2014
49
Burst of Particle Showers associated with Lightning
• Burst == 3 particle showers within 1ms.
• 5 Bursts in 5 years
• ~10-4 burst from randoms (of CR-EAS).
core
lightning
core
•
•
•
•
Core locations ~2km apart.
Common “origin” ~3km above Ground.
(highly curved shower front r~3km)
Lightning found within 1ms (NLDN-db)
Lightning location ~ core location
T. Okuda
CosPA 2013
Thank You, and see you all
@UHECR2014 in Springdale, Utah
for Oct.12th-15th.
Thanks are also for Douglas Bergman, Kazumasa Kawata,
John N. Matthews, Grisha Rubtsov, Pierre Sokolsky,
Peter Tinyakov and the TA colleagues for preparing
this presentation quickly.
Anisotropy at 1018eV
v  Large-scale anisotropy search
- verify AGASA anisotropy
- Statistics TA =1.6 x AGASA
à No strong anisotropy
K.Kawata
ICRC2013
Oversampling 20°-radius circle
v  Point-like source search
- Neutral particle from our Galaxy
à No significant excess
Stringent upper limit in north sky
TA Data>1EeV
TA Data(1018-1018.4eV)
Oversampling 20°-radius circle
18
14