ASTROPHYSICAL SCENARIOS Félix Mirabel Neutron stars amp Black holes in stellar binary systems that radiate in gammarays Will not refer to other types gammaray ID: 216415
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GAMMA-RAY COMPACT BINARIES*ASTROPHYSICAL SCENARIOS
Félix Mirabel
*
Neutron stars & Black
holes
in
stellar
binary
systems
that
radiate
in gamma-rays.
(Will not
refer
to
other
types gamma-ray
stellar
binaries
,
e.g
. Eta Carina) Slide2
COMPACT GAMMA-RAY BINARIES IN 2006 The
only
known
were PSR B1259-63, LSI +61 303 & LS 5039
g
-rays produced by inverse Compton scattering: relativistic electrons collide with stellar and/or synchrotron photons and boost their energies to HE & VHE ranges. In PSR B1259-63 the electrons are powered by the rotational energy of the pulsar. In microquasars relativistic electrons would come from accretion-powered jets and in that publication I proposed as candidate sources Cyg X-1 & Cyg X-3.
PSR B1259-63
Mirabel: Perspective in Science (2006) Slide3
COMPACT GAMMA-RAY BINARIES IN 2012
Mirabel: Perspective
in
Science (2012) Sp Types of donors
: Casares et al. (2012)
Name g-ray s Sp Type PSR B1259-63 HE, VHE O9.5 VeAGL J2241+4454 HE ? B3 IV ne+shHESS J0631+057 VHE B0 VpeLS I+61 303 HE, VHE B0 Ve (?) Name g-ray s Sp Type LS 5039 HE, VHE O6.5 V((f)) 1FGL J1018 HE, VHE? O6 V((f))Name g-ray s Sp TypeCyg X-3 HE WNE([2,5])Cyg X-1 HE, VHE? O7 VLS I+61 303 HE, VHE B0 Ve (?)
g
-ray
binaries
are
NSs
and
BHs
orbiting
massive stars
So far no detection of any LMXB (e.g. GRS 1915+105) The g-ray emission is modulated with the orbital period and/or periastron
HE, E>100 MeV & VHE, E>100 GeV PRODUCED BY LEPTONIC AND HADRONIC INTERACTIONS
HE in
superior
conjunctionSlide4
I
n this area of research, (namely “Compact
g
–ray binaries”), it would be convenient if CTA could have a low energy threshold. This is also the case to make progress in other areas of high energy astrophysics, such as in studies of Pulsars, GRBs, AGN…
In
this context, high photon stadistics at a few tens of GeVs would be an advantage to unambiguously identify compact gamma-ray binaries in the Milky Way, Slide5
FUTURE CHALLENGES IN THIS AREA OF RESEARCH
The typical confusion in star formation
regions
can be
overcomed by correlated
multi-l orbital modulations in the gamma-rays, X-rays, IR, and radio waves. (e.g. Cyg X-3, 1FGL J1018.6-5856). CTA may provide the required photon statistics for high sensitivity and angular resolution, that would identify a larger population of compact gamma-ray
sources in the Milky
Way
.
Since
as
compact
binaries
, AGN,
blazars
,
GRBs
& neutron stars are rapidly variable sources of g-rays, the “CTA-STAC underlines the importance of all the detector systems, SST, MST and LST, for making possible observations with unique sensitivity, including transient sources down to 20 GeV » Slide6
OLD SIMULATION AS A FUNCTION OF ALTITUDESlide7
NEW SIMULATION UP TO 50 GeV AS A
FUNCTION OF ALTITUDE FOR 50h
3700 m
2000 m
Would
the sensitivity change for much shorter exposures? Could the simulations be extended down to 20 Gev? Maier (2013) presented by Hinton at the CTA SSC