Transcript Orihin and evolution of magnetars

Magnetars inside
antimagnetars
Sergei Popov
(SAI MSU)
(co-authors: A. Kaurov, A. Kaminker)
Kaplan arXiv: 0801.1143
NS birth rate
[Keane, Kramer 2008, arXiv: 0810.1512]
CCOs
For three sources there are strong indications for
large (>~100 msec) initial spin periods and
low magnetic fields:
1E 1207.4-5209 in PKS 1209-51/52,
RX J0822-43 in Pup A and
PSR J1852+0040 in Kesteven 79
See list in: 1301.2717
Puppis A
Anti-magnetars
Star marks the CCO in Kes 79
(from 0911.0093)
Note, that there is no room
for antimagnetars from the
point of view of birthrate
in many studies of different
NS populations.
Further evolution of CCOs
Popov et al.
MNRAS 2010
Halpern,
Gotthelf
CCOs
1010
Chashkina,
Popov 2012
PSRs+
Magnetars+
Close-by coolers
1012
HMXBs
B
1011
1013
Among young isolated NSs about 1/3 can be related to CCOs.
If they are anti-magnetars, then we can expect that 1/3 of NSs
in HMXBs are also low-magnetized objects.
They are expected to have short spin periods <1 sec.
However, there are no many sources with such properties.
Possible solution: emergence of magnetic field (see Ho 2011).
B
Yakovlev, Pethick 2004
Where are old CCOs?
According to cooling studies they have to be bright till at least 105 years.
But there are no candidates in the solar vicinity.
We propose that a large set of data on HMXBs and cooling NSs
is in favour of field emergence on the time scale 104 ≤ τ ≤ 105 years.
Some PSRs with thermal emission for which additional heating was proposed
can be descendants of CCOs with emerged field.
The final element for the GUNS?
The field is buried by fall-back, and then re-emerges on the scale ~104 yrs.
Bernal, Page, Lee 2013
Vigano, Pons 2012
Emerged pulsars in the P-Pdot diagram
Emerged pulsars are expected to have
P~0.1-0.5 sec
B~1011-1012 G
Negative braking indices or at least n<2.
About 20-40 of such objects are known.
Parameters of emerged PSRs:
similar to “injected” PSRs
(Vivekanand, Narayan, Ostriker).
The existence of significant fraction
of “injected” pulsars formally
do not contradict recent pulsar current studies
(Vranesevic, Melrose 2011).
Part of PSRs supposed to be born with
long (0.1-0.5 s) spin periods can be
matured CCOs.
Espinoza et al. arXiv: 1109.2740
“Hidden” magnetars
Halpern, Gotthelf 2010
Kes 79. PSR J1852+0040. P~0.1 s
Shabaltas & Lai (2012) show that
large pulse fraction of the NS in Kes
79 can be explained if its magnetic
field in the crust is very strong:
few ×1014 G.
• If submergence of the field happens rapidly,
so the present day period represents the initial one
• Then, the field of PSR 1852 was not enhanced
via a dynamo mechanism
• Detection of millisecond “hidden” magnetars
will be a strong argument in favour of dynamo.
arXiv: 1307.3127
Magnetar bursts
Growing twist
(images from Mereghetti arXiv: 0804.0250)
Non-global twist model
1306.4335
What causes what?
The chicken or the egg?
Crust or magnetosphere?
It would be nice to have
magnetars without crust,
and magnetars without
magnetospheres.
Hypothetical highly magnetized
quark stars can be the first of them,
and “frozen” (aka “hidden”)
magnetars – can be testbeds
to study crustal processes without
magnetospheric phenomena.
Crust of magnetosphere?
What triggers the burst?
What provides energy?
Beloborodov, Levin 2014
Masada et al. 2010
Lander et al. 2014
How often do magnetars burst?
Perna, Pons 2011
Visibility of the thermal effect
If a NS has low quiescent luminosity, then an additional release of
thermal energy during an outburst can be well visible.
If the luminosity was already high – then it is very difficult
to observe an outburst.
Pons, Rea 2012
What about Kes 79?
Very stable
flux for years!
(see also
Bogdanov 2014)
Why?
Always in a high
state?
Or nearly no
activity for years?
AXP CXO
J010043.1-7211
is known to have
constant flux
for a long time.
Halpern, Gotthelf 2010
RCW 103 as a “hidden” magnetar
with active crust
Kes 79 looks very quiet, stable ....
...but RCW 103 – not.
•
•
•
•
Fluxes
Temperatures
Variability
Pulse profile changes
Only thermal radiation!
No traces of any kind of
magnetospheric activity.
De Luca et al. (2006)
Let us model RCW103!
Cartoon of the model
Photons and neutrinos
Mostly released heat
is carried away by νs.
Kaminker et al. 2014
How bright it can be?
If we move the heating
layer down (towards higher
density) – then the surface
emission is not strongly
enhanced.
Modeling RCW103
Heating was on for 120 days.
Different curves correspond
to different composition of
the heat blanketing layer.
Conclusions
•Studies of “hidden” magnetars
can be used to probe
processes in the crust of
strongly magnetized NSs.
• Kes 79 looks very stable,
which is strange for a
“hidden” magnetar
• RCW103 can be a ”hidden”
magnetar, and its activity
can be explained in this model.
A compact object in SN1987A
can be ``hidden’’ magmetar,
as it was born soon after a
coalescence (Morris, Podsiadlowski 2007)
and strong fall-back has been
proposed to explain its properties
(Chevalier 1989, Bernal et al. 2010).