the gev-tev connection - 東京工業大学 · 2018-06-02 · the gev-tev connection stunning...
TRANSCRIPT
The GeV-TeV connection… and Supernova remnants, Pulsar Wind Nebulae and other Galactic sources
S. Funk, Kavli Institute for Astroparticle Physics & Cosmology, Stanford & SLAC
Start to connect LAT to TeV sources
will talk about what we knew before the LAT, what we expect and some very early results ...
The GeV-TeV connection
Stunning diversity of astrophysical TeV accelerators
Patchy observations apart from scan of Galactic plane (l=+-60, b = +-5)
Typical energy flux densities: 10-12 ergs cm-2 s-1 (1-10 TeV) 1 degree
X γ
x0.5x0.5
Aharonian et al., Nature, 439, 695 (2006)
Comparing TeV sources to EGRET
Hints for GeV emission from EGRET for some of the most prominent and brightest TeV sources
Galactic Center
RX J1713.7-3946
LS 5039
Kookaburra, IC 443, HESS J1825-178
More on this from Fermi-LAT
GLAST (IC)
GLAST (π0)
HESS
Reimer & Funk, ASSci, 309, 203 (2006)
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
Aharonian et al., A&A 460, 365 (2006)
Comparing TeV sources to EGRET
EGRET: Energy flux (1-10 GeV)H.E.S.S.: Energy flux (1-10 TeV)GLAST: Sensitivity (1-yr) above 1 GeV (l=10, b=0)
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
Instrumental parametersDifferential sensitivity significantly better in TeV instrumentsAll sky coverage for Fermi-LAT vs patches of the skyAngular resolution: only comparable at the high-energy endDiffuse model is additional complication for Fermi-LAT
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
-4
-2
0
2
4
1015202530
3EG J1812-1316
3EG J1823-1314
3EG J1824-1514
3EG J1826-1302
3EG J1837-0423
3EG J1837-0606
HESS J1809-193
HESS J1813-178
HESS J1825-137 HESS J1826-148
HESS J1834-087
HESS J1837-069
-4
-2
0
2
4
-10-50510
3EG J1718-3313
3EG J1734-3232
3EG J1736-2908
3EG J1744-3011
3EG J1746-28513EG J1800-2338
3EG J1809-2328
HESS J1745-290
HESS J1745-303
HESS J1747-281
HESS J1800-240
HESS J1801-233
HESS J1804-216
3503550510
)!G
ala
cti
c L
ati
tud
e (
-4
-2
0
2
4
330335340345350
3EG J1639-4702
3EG J1655-4554
3EG J1710-4439
3EG J1714-3857
HESS J1614-518
HESS J1616-508HESS J1632-478HESS J1634-472
HESS J1640-465HESS J1702-420
HESS J1708-410
HESS J1713-381
HESS J1713-395
HESS J1718-385
)!Galactic Longitude (
Before Fermi-LATSystematic study in inner Galaxy between EGRET and H.E.S.S.
Check whether H.E.S.S. src is within EGRET contour
0 sources within 68% (chance coinc.: 0.5)
2 sources within 95% (chance coinc.: 1.4)
3 sources within 99%(chance coinc.: 2.5)
No coincidenceWithin 95%Within 99%
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
Spectral connectionFor some of the positionally coincident sources there is a good spectral match
For some sources H.E.S.S. data put severe constraints on emission model
Fermi-LAT will measure through whole band
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
Spectral connectionFor some of the positionally coincident sources there is a good spectral match
For some sources H.E.S.S. data put severe constraints on emission model
Fermi-LAT will measure through whole band
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
Physical expectation
For IC sources a GeV-TeV connection is rather unlikely (need old source or high B-field)
For pion-decay: connection natural, but remember the difference in energy flux sensitivity
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
Physical expectation
For IC sources a GeV-TeV connection is rather unlikely (need old source or high B-field)
For pion-decay: connection natural, but remember the difference in energy flux sensitivity
SF,
Rei
mer
, O.,
Torr
es, D
., H
into
n, J
. ApJ
679
, 129
9 (2
008)
The 3-month Fermi-LAT data
Fermi all-sky data allows for systematic study with TeV data.
Identified sources are AGN, Pulsars, LMC, high-mass X-ray binaries, the Earth, the Sun and the Moon
The Inner Galaxy
3 sources within 95% EGRET contour
Now with the LAT:
Confirm 2 of the 3
LS 5039
W28 SNR
+ GC source
+ HESS J1616-508
+ HESS J1834-087
+ HESS J1804-216
Beyond Inner Galaxy:
LS I61+303
IC443, ...
No coincidenceWithin 95%Within 99%
The Inner Galaxy
3 sources within 95% EGRET contour
Now with the LAT:
Confirm 2 of the 3
LS 5039
W28 SNR
+ GC source
+ HESS J1616-508
+ HESS J1834-087
+ HESS J1804-216
Beyond Inner Galaxy:
LS I61+303
IC443, ...
No coincidenceWithin 95%Within 99%
Coincidences with SNRs / PWNePositional coincident sources with SNRs and PWNe such as:
W28, W41, W51, IC443, Kookaburra, ...
As seen for CTA 1 and many others, the LAT detects many pulsars
Pulsed emission and extension analysis crucial for association
Abd
o et
al,
Sci
ence
, 322
, 121
8 (2
008)
... but probably not young SNRsBrightest young TeV SNR (RX J1713.7-3946) not in the bright source list (same for Cas A, RCW 86, Vela Jr., SN 1006)
Remember difference in energy flux sensitivity between Fermi-LAT and TeV telescopes
Old SNRs are preferred targets (lots of GeV-emitting protons still there) A
haro
nian
& A
toya
n, A
&A
309
, 917
(199
6)
The Crab Pulsar and Its Nebula
Most prominent example: Crab Nebula
Clearly detected in off-pulse emission
Spectrum matches the TeV spectrum
All phases
Off-pulseco
urte
sy M
.H. G
rond
in (L
AT-C
olla
bora
tion)
cour
tesy
M.H
. Gro
ndin
(LAT
-Col
labo
ratio
n)
cour
tesy
M.H
. Gro
ndin
(LAT
-Col
labo
ratio
n)
The Crab Pulsar and Its Nebula
Most prominent example: Crab Nebula
Clearly detected in off-pulse emission
Spectrum seems to connect nicely to the TeV spectrum
cour
tesy
M.H
. Gro
ndin
(LAT
-Col
labo
ratio
n)
cour
tesy
M.H
. Gro
ndin
(LAT
-Col
labo
ratio
n)
-4
-2
0
2
4
1015202530
3EG J1812-1316
3EG J1823-1314
3EG J1824-1514
3EG J1826-1302
3EG J1837-0423
3EG J1837-0606
HESS J1809-193
HESS J1813-178
HESS J1825-137 HESS J1826-148
HESS J1834-087
HESS J1837-069
LAT PSR J1826-1256
LS 5039
-4
-2
0
2
4
-10-50510
3EG J1718-3313
3EG J1734-3232
3EG J1736-2908
3EG J1744-3011
3EG J1746-28513EG J1800-2338
3EG J1809-2328
HESS J1745-290
HESS J1745-303
HESS J1747-281
HESS J1800-240
HESS J1801-233
HESS J1804-216
LAT PSR J1732-31
LAT PSR J1809-2332
3503550510
)!G
ala
cti
c L
ati
tud
e (
-4
-2
0
2
4
330335340345350
3EG J1639-4702
3EG J1655-4554
3EG J1710-4439
3EG J1714-3857
HESS J1614-518
HESS J1616-508HESS J1632-478HESS J1634-472
HESS J1640-465HESS J1702-420
HESS J1708-410
HESS J1713-381
HESS J1713-395
HESS J1718-385
PSR J1709-4429
)!Galactic Longitude (
Summary
We have just started the process of systematically comparing the GeV to TeV sky
Bright TeV sources might not be bright GeV sources (and vice versa)
Young SNRs not in bright source list
Many pulsars, need extension measurement for association
… exciting times ahead of us