Transcript Discovery of new population (?) of isolating neutron star

Discovery (?) for new population
of isolated neutron star
“Transient radio bursts from rotating neutron
star” M.A. McLaughlin et al., Nat. Feb. 16, 2006
“Discovery of the X-ray counter part to the
rotating radio transient J1819-1458
S.P. Reynolds et al., ApJL, vol. 636, L71, 2006
Observation
 Parkes multibeam survey between January
and February 2002.
Isolated bursts radio emissions from the eleven
sources
 Since August 2003, all the sources have been
re-observed at least nine times
- Between four to 229 bursts were detected
from each sources
Very bright radio sources!!
 14000-MHz flux densities is range
0.1 to 3.6Jy
ex. ~mJy for normal radio pulsar
What is the object?
 The duration of the each burst is
between 2-30ms.
 The average time between the bursts is
range between 4m to 3h.
 Periodicity searches identify
as the rotating objects with
0.4 - 7s period ranges
Neutron star?
T
2-30ms
4m-3h
 CHANDRA observed X-ray counter
part (CXOU J181934.1-145804)
from one (J1819-1458) of them
kT~0.12keV, R~10km
Neutron
Pulsar parameters
Normal radio pulsar?
 Only burst like emissions are observed
(no regular pulsed radio emission)
 Peak flux densities are higher than
normal radio emission from the pulsar
Only giant pulses are
observed ?
Giant pulse?
 Too lower magnetic field, 1~10G, at the
light cylinder.
ex. Crab pulsar ~106G
 Too wide pulse width, 2~30ms
ex. Crab pulsar ~ nano s
If emission width is determined by plasma frequency,
the emission height is h>Rlc.
ex. Crab pulsar ~ 10 R (private communication
with Jaroschek)
Summary
 The burst like radio emissions were
measured from 11 rotating neutron star.
 The radio emission mechanism would
be different from normal and giant
pulsed emissions.
 These new discovered objects belong to
new population of isolated neutron star
Rotating RAdio Transients (RRATs)