ジェットを”持たない”銀河からの高エネルギーガンマ線放射
林田 将明（東京大学宇宙線研究所)
201４年10月2日「高エネルギーガンマ線でみる極限宇宙2014」@東大柏キャンパス
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  1	  Gamma-ray emission from galaxies
AGNs	  with	  rela.vis.c	  jet	  e+/e-­‐	  νFν	Inverse-­‐Compton	  scaCering	  by	  electrons	  in	  the	  jets	  	  ν	  Blazar	  	  	  Radio	  Galaxies	  	  • low power BL Lac

FR I• high power FSRQFR IIsmall	  viewing	  angle	  -­‐>	  rela<vis<c	  beaming	  mis-­‐aligned	  blazar	  ?	  

14/10/02	  no relativistic jet!
(Seyferts, starbrust, galaxies)#

Masaaki	  Hayashida	  (ICRR)	  2	  extra-galactic γ-ray sources
with	  rela*vis*c	  jet	  blazar	  (761)	  radio	  galaxies	  	  (10)	  	  BL	  Lac	  (395)	  FR-­‐I	  FSRQ	  (310)	  FR-­‐II	  Seyfert	  radio	  loud	  14/10/02	  no	  bright	  jet	  galaxies	  	  (3+1)	  (2FGL)	  	  	  starburst	  (4)	  	  radio	  quiet	  Masaaki	  Hayashida	  (ICRR)	  3	  extra-galactic γ-ray sources
with	  rela*vis*c	  jet	  blazar	  (761)	  no	  bright	  jet	  radio	  galaxies	  	  (10)	  	  Seyfert	   galaxies	  	  BL	  Lac	  (395)	  FR-­‐I	  (3+1)	  FSRQ	  (310)	  FR-­‐II	  starburst	  (4)	  	  radio	  loud	  14/10/02	  (2FGL)	  	  	  radio	  quiet	  Masaaki	  Hayashida	  (ICRR)	  4	  starburst galaxies
an example of emission model (Lacki+14, ApJ)#

emission origins inthe HE (>100 MeV)
γ-ray band are#
• Bremsstrahlung#• inverse-Compton#• Pionic (π0àγγ)#

14/10/02	  Masaaki	  Hayashida	  (ICRR)	  5	  nucleus activity in radio-quiet galaxies“radio	  quiet”	  does	  not	  mean	  ‘radio	  silent’!!	  
“jet” (non-relativistic) in Seyfert!
•240-pc jet in NGC 4151(Sy1.5) is two-sided
and highly collimated(diameter < 1.4 pc, v < 0.03c at 0.1-10pc scale)#extended “lobe” (a few-10 kpc)!
Fermi bubble in our Galaxy!
（明日、佐々木さん）#14/10/02	  +Ultra Fast Outflow(UFO)
Masaaki	  Hayashida	  (ICRR)	   (井上Sさん）#6	

hadronic process in the disk
p-p interactions in the innermost parts of the accretion disk
if L < 10-3LEdd(明日、木村さん？）
Fermi

BH spin

Credit:	  NASA/CXC/M.Weiss

First idea was discussed for
Galactic black hole systems(Mahadeven et al.1997:Oka & Manmoto 2003),and then, applied to AGN by
14/10/02	

Niedzwiecki+13 ApJ
Masaaki	  Hayashida	  (ICRR)	  7	  Source samples(Fermi-­‐LAT	  2012	  ApJ,	  755)	  • IR galaxies: 64 low-redshift (z < 0.06) galaxies
based on HCN Survey (Gao & Solomon 2004)#(star-formation activity evidenced by dense molecular gas )#+ 5 local galaxies##(Fermi-­‐LAT	  2012	  ApJ,	  747,	  CA:MH)	  select	 cut	• Radio-quiet Seyfert galaxies:
120 sources based on
Swift-BAT 58 month catalog#
hard X-ray radio loudness parameter#

10-48	  8	14/10/02	  Masaaki	  Hayashida	  (ICRR)	  Analysis results
Data: 3-years Fermi-LAT data above 100 MeV!
• 7 LAT detections:
SMC, LMC, M31,M82, NGC 253,
NGC 4945, NGC 1068#( 2 TeV detections:M82, NGC 253)#• No detection inradio-quiet Seyferts#
upper	  limits	  >	  100	  MeV	  The mean ULs (>100 MeV) :~ 4×10-9 ph cm-2 s-1#possible detections?
ESO 323-G077, NGC 6814#

14/10/02	  Masaaki	  Hayashida	  (ICRR)	  9	  Global Emissions
Radio and Far-IR SED for M82!

Empirical Radio!
Far-IR Correlation!

Reviewed	  by	  e.g.	  Condon	  (1992)	  Thermal	  Dust	  Synchrotron	  Thermal	  Bremsstrahlung	  Yun et al. (2001)#(Kennicutt 1998)(Yun et al. 2001)
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  10	  Luminosity Scaling Relations
Ackermann et al. 2012, ApJ, 755, 164#(Kennicutt 1998)

Gamma-ray vs. IR
Luminosity
Power law slope = 1.17 ± 0.07
Sqrt(variance) = 0.24
Upper limits included in fit
Correlation significance accounting
for selection effects and distanceuncertainties
P < 0.005(P < 0.02 excluding galaxies
hosting Swift -BAT AGN)
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  11	  Luminosity Scaling Relations
Ackermann et al. 2012, ApJ, 755, 164#(Kennicutt 1998)

Gamma-ray vs. IR
Luminosity
Luminosity ratio is measure of
gamma-ray yield per unit starformation
In “calorimetric limit”, inelastic
collisions dominate CR energy losses(here, assume each SNR injects
1050 erg of CR nuclei)(most probably)!

gamma rays originate from CR!
in (all) star-forming galaxies !!!
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  12	  However,,#

14/10/02	  Masaaki	  Hayashida	  (ICRR)	  13	  However,,#(Hayashida+13, ApJ)#

one exception!!!
gamma-ray flux is higher than flux expected from Calorimetric limits#
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  14	  Circinus galaxy	•••(RA, Dec: J2000) = (14h13m09.95s, -65d20’21.2”) (southern source)#
Distance: 4.2 Mpc (Tully et al. 2009)#
Black hole mass (1.7±0.3)x106Msun (Greenhill et al. 2003),
also known as a starburst galaxy and Seyfert 2 type AGN.#• kpc-scale radio lobes, as well as jet-like structure(e.g., M. Elmouttie et al. 1998)	
Radio	  1.4	  GHz	  (ATCA)	  Map	

14/10/02	  Masaaki	  Hayashida	  (ICRR)	  15	  GeV	  γ-­‐ray	  TS	  map	  with	  a	  radio/IR	  map	(Hayashida+13,ApJ)#

4-year observation by Fermi-LAT!
radio	  contour	  (20	  cm)	color:	  H-­‐band	  (2MASS)	  contour:	  1.4	  GHz	  (ATCA)	  Circinis	  is	  well	  located	  inside	  of	  	  LAT	  68	  %	  CL	  region.	  

Circinus	  TS:	  58	  (~7	  σ),	  a	  single	  point-­‐like	  source	  14/10/02	  Masaaki	  Hayashida	  (ICRR)	  16	  Gamma-ray spectrum	
(Hayashida+13,ApJ)#• Simple	  power	  law,	  Index:	  2.19±0.12	  • Flux	  (>	  100MeV):	  (1.88±0.58)x10-­‐8	  ph	  cm-­‐2	  s-­‐1	
Black: Circinus#
Orange: NGC 253#
Blue: M82#

• No indicationof curved
spectral shape#• No significant
variability#

14/10/02	  Masaaki	  Hayashida	  (ICRR)	  17	  Comparison in the γ-ray and IR/radio	(Hayashida+13,ApJ)#• Circinus	  Galaxy	  shows	  higher	  Lγ/LIR	  and	  in	  Lγ/Lradiora<os	  	  • higher	  than	  the	  calorimetric	  limit	  (with	  10%	  eﬃciency)	  calorimetric	  limit	  when	  ηESN=1050	  erg	  14/10/02	  Masaaki	  Hayashida	  (ICRR)	  18	  Origin	  of	  γ	  ray	  emission?	  
• relativistic jets? -> no radio result shows apronounced nuclear jet activity• Disk? (including hadronic process)à our Seyfert study revealed such emission
should be less than a few % of X-ray luminosityà not sufficient to account for the excess• Lobes? (see next slides)

14/10/02	  Masaaki	  Hayashida	  (ICRR)	  19	  Radio	  images	  and	  ﬂux	We	  extract	  radio	  ﬂuxes	  from	  each	  region	  in	  accordance	  disk	
1.4	  GGHz	  Hz	  1.4	  with	  Elmouje	  et	  al.	  1998	  	  core	
core		  lobe	
lobe	
Deﬁni<on	  of	  components:	  <lobe>	  :SE:	  ellipse	  with	  r=70",55”	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  NW:	  circle	  r=44.6"	  <core>	  :	  circle	  r=35”	  	  2.4	  GGHz	  Hz	  2.4	  plume	  plume	  4.8	  GGHz	  Hz	  4.8	  8.6	  GGHz	  Hz	  8.6	  lobes+plumes	  contribute	  to	  ~10	  %	  level	  of	  the	  total	  radio	  ﬂux	  14/10/02	  20	  (ATCA	  data	  provided	  by	  M.	  Elmouje)	  Masaaki	  Hayashida	  (ICRR)	  Broad-­‐band	  SED	Black	  circle:	  total	  ﬂuxes	  of	  the	  galaxy	  All	  points	  are	  corrected	  for	  the	  •Galac<c	  absorp<on	  ••	  	  	  	  	  	  	  	  	  emission	  model	  for	  the	  lobes	  +	  plumes	  B	  =	  5-­‐10	  µG	  equipar<<on	  (ue/uB=1)	  seed	  photons	  • CMB	  • FIR-­‐to-­‐op<cal	  • UV-­‐to-­‐hard	  X-­‐ray	  lobes+plumes
synchrotron!

IC!

γ-­‐ray	  spectrum	  expected	  from	  γ-­‐IR	  rela<on	  in	  starbursts	  Lobe	  can	  hardly	  account	  for	  the	  observed	  GeV	  emission	  (unless	  very	  far	  from	  the	  equipar<<on)	  14/10/02	  the origin is not clear, yet,,,,21	  Masaaki	  Hayashida	  (ICRR)	  CTA case for Circinus galaxy• 50 hours observations#
E2 dN/dE (TeV cm-2 s-1)

intrinsic spectrum-1110

expected spectrum (CTA), 50.00h

LAT data#6’#

10-12

10-13

preliminary!
10-14
0.0010.002

0.010.02

0.1 0.2

12 34

10 20
100
energy E(TeV)

Blue: simple power low#
Red: × exp(−E/5TeV)#
Green: × exp(−E/0.5 TeV)#

can clearly detect cut offs!!
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  can resolve!
disk and lobe!!!
22	  GeV-TeV spectra in starbursts
Currently,,,,#
Gamma-ray spectra of M82 and NGC 253 are well describedby simple power laws given current statistical precision
NGC 253
H.E.S.S.
Collaboration2012

14/10/02	  Masaaki	  Hayashida	  (ICRR)	  23	  CTA Science Opportunities
Gamma-ray detections ofNGC 253 with future
differential sensitivity
curves overlaid

NGC	  253	  defined as 2σ detections inbins of 1/3 decade in energy(courtesy Stefan Funk,
Keith Bechtol
see also arXiv:1205.0832)

Example CTA Research Areas•••Are γ-ray spectra of starbursts more complex than simple power laws?
Highest energy CRs in starburst systems?
Can the starburst / disk be separated with CTA imaging?
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  24	  CTA Science Opportunities
Gamma-ray detections ofNGC 253 with future
differential sensitivity
curves overlaid

NGC	  253	  M82, CTA 30 h#

defined as 2σ detections inbins of 1/3 decade in energy(courtesy Stefan Funk,Keith Bechtol
see also arXiv:1205.0832)(Acero+13 Aph) #Example CTA Research Areas•••

Are γ-ray spectra of starbursts more complex than simple power laws?
Highest energy CRs in starburst systems?
Can the starburst / disk be separated with CTA imaging?
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  25	  Cascade emission in galaxies
Y .Inoue 2011, ApJ#

HE gamma-ray (above 10 TeV) can not escape from galaxies #14/10/02	  Masaaki	  Hayashida	  (ICRR)	  26	  HE Astrophysical Neutrinos(IceCube coll.14, PRL: 詳細は明日の石原さん）#

37 events: flux: E2Ф ~ 10-8 GeV cm-2 s-1 sr -1 #No significant clustering of the events#Candidate sources à starbursts ? !
(extragalactic, many sources, Emax~1015-17 eV?) #(see also Murase+13 PRD, Chang & Wang 14 ApJ, Tamborra+14 JCAP)#
14/10/02	  Masaaki	  Hayashida	  (ICRR)	  27	  Neutrino emission
102
νF[erg/cm/s]
ν-10

10-11

Neutrino
π 0-dec.

10test calc.#
by Asano(ICRR)#
IC

ν~1.44 γ-12(π0-dec)!

10-13
109
14/10/02	  1010

1011

1012

1013

Masaaki	  Hayashida	  (ICRR)	  1014

1015
ε [eV]
28	  contribution of SB galaxies (with Asano-san)Observational results by Fermi :#Γ=2.2!

(0.1GeV)L0.1=1.34×10-5LIR!

Mpc-­‐3	  (erg/s)-­‐1	

Infrared Luminosity Function (Gruppioni+13)	

(>0.01L*)#

1.9×1040 erg/s/Mpc3#

10 -48α=1.00, σ=0.35, L*=1011.17Lsun#

10 -49

10 -50z=0#

10 -51(0.1GeV)L0.1/Mpc3=2.56×10-5 erg/s/Mpc3!
!

10 -52
1 ´ 10 43

5 ´ 10 431 ´ 10 44

5 ´ 10 441 ´ 10 45

5 ´ 10 45

LIR	

Converted to ν : #14/10/02	  Masaaki	  Hayashida	  (ICRR)	  29	  contribution of SB galaxies (with Asano-san)if neutrino index = 2#(z<4)#: constant#

too low if (1+z)3!
or very high evolution!

IceCube:!

E2Ф (@PeV) ~ 10-8 GeV cm-2 s-1 sr-1	  	  	  14/10/02	  Masaaki	  Hayashida	  (ICRR)	  30	  contribution of SB galaxies (with Asano-san)if neutrino index = 2#(z<4)#: constant#(Ackermann+14, ApJ)#

too low if (1+z)3!
or very high evolution!

IceCube:!

E2Ф (@PeV) ~ 10-8 GeV cm-2 s-1 sr-1	  	  	  14/10/02	  Masaaki	  Hayashida	  (ICRR)	  31	  Summary• Starbursts have been established as γ-ray source amongradio-quiet galaxies#– globally: Γ~2.2, following Lγ vs. LIR (vs. Lradio) correlation#• The origin of γ-ray emission is likely to originate fromcosmic rays interacting with ISM #• One expectation: Circinus galaxy#– shows higher γ-ray luminosity than expected from CR origin#– but, the emission origin is not clear, yet#

• CTA helps to understand the γ-ray origin and cosmic-ray
properties#– detailed γ-ray spectral shape (cut off?)#– Highest energy CRs in starburst systems?
– PeV neutrino origin???#14/10/02	  Masaaki	  Hayashida	  (ICRR)	  32