1. Isolated Neutron Stars for ART, eROSITA and LOBSTER
Sergei Popov
(SAI MSU)
Observer

2. Good old classics
The pulsar in the Crab nebula
A binary system

3. The new zoo of neutron stars
During last 10 years
it became clear that neutron stars
can be born very different.
In particular, absolutely
non-similar to the Crab pulsar.
Compact central X-ray sources
in supernova remnants.
Anomalous X-ray pulsars
Soft gamma repeaters
The Magnificent Seven
Unidentified EGRET sources
Transient radio sources (RRATs) ….

4. Main reviews NS basics: physics/0503245
SGRs & AXPs: astro-ph/ !!!!
Recent observations
AXPs astro-ph/
SGRs astro-ph/
Theory of magnetars: astro-ph/
Central compact X-ray
sources in supernova
remnants: astro-ph/
The Magnificent Seven: astro-ph/ !!!!
RRATs: astro-ph/
Cooling of NSs: astro-ph/ !!!!

5. Wanted! There are several types of uncatchable
compact objects which still are not detected:
Isolated accreting NSs
Isolated BHs
Isolated NSs on the Propeller stage
NSs in the galactic halo
Extragalactic magnetars
Also we want to detect more cooling INSs.
Finally, there are several interesting types
of accreting binaries, which can be detected:
Massive NS accreting from WDs
Accreting magnetars (including magnetors)

6. Evolution of NSs. I.: temperature
[Yakovlev et al. (1999) Physics Uspekhi]
First papers on the thermal
evolution appeared already
in early 60s, i.e. before
the discovery of radio pulsars.

7. Evolution of neutron stars. II.: rotation + magnetic field
Ejector → Propeller → Accretor → Georotator
1 – spin down
2 – passage through a molecular cloud
3 – magnetic field decay
astro-ph/
See the book by Lipunov (1987, 1992)

8. Isolated NS Census Rather conservative evolutionary scheme was used.
For example,
supersonic propellers
have not been considered
(Ikhsanov 2006).
astro-ph/

9. Accreting isolated NSs
At small fluxes <10-13 erg/s/cm2 accretors can become more abundant
than coolers. Accretors are expected to be slightly harder:
eV vs eV. Good targets for eROSITA!
From several hundreds up to
several thousands objects
at fluxes about few X 10-14,
but difficult to identify.
Monitoring is important.
Also isolated accretors can
be found in the Galactic center
(Zane et al. 1996,
Deegan, Nayakshin 2006).
astro-ph/

10. Young cooling radio dim NSs
Source
Period, s
RX 1856
7.05
RX 0720
8.39
RBS 1223
10.31
RBS 1556
6.88?
RX 0806
11.37
RX 0420
3.45
RBS 1774
9.44
The Magnificent seven
Radio quiet (?)
Close
Young
Thermal emission
Spectral features
Long periods
Poster by Malofeev

11. More cooling NSs eROSITA has better sensitivity
for sources with T>200 eV.
We expect that there are more
INS in the directions towards
OB associations.
These INS are younger and hotter
than the Magnificent Seven.
eROSITA can find few dozens.

12. Known magnetar candidates
AXPs
CXO 4U 1E
CXOU J
1 RXS J
XTE J 1E
AX J 1E
SGRs
+candidates

13. SGRs and AXPs

14. Are SGRs and AXPs brothers?
Bursts of AXPs
Spectral properties
Quiescent periods of SGRs ( since 1983)
Gavriil et al. 2002

15. AXPs: bursts and transients
Typical bursts of SGR ,
SGR
And of AXP 1E detected by RXTE
(from Woods, Thompson astro-ph/ )

16. SGRs: monitoring and extraG
SRG detectors can contribute to
observations of SGRs.
[D. Frederiks et al. astro-ph/ ]

17. Compact central X-ray sources in supernova remnants
Cas A
Puppis A

18. RRATs: also young coolers?
Rotating Radio Transients
have been discovered recently
(McLaughlin et al. 2005).
They can represent a very
numerous population of NSs.
One of RRATs is identified in
Chandra data as a young
cooling NS. Slightly hotter
than the Magnificent seven
(Reynolds et al. 2006).

19. Unidentified EGRET sources
Grenier (2000), Gehrels et al. (2000)
Unidentified sources are divided into several groups.
One of them has sky distribution similar to the Gould Belt objects.
Search in 56 EGRET error-boxes resulted in no PSR detections
(Crawford et al. 2006).
GLAST (and, probably, AGILE) can help to solve this problem.
eROSITA and LOBSTER also can contribute.

20. Проект Джильда-Гала Проект в основном создается учеными МИФИ
(Институт Космофизики)
Солнечно-синхронная
круговая орбита
Высота орбиты 835 км
Наклонение градуса
Чувствительность от 10 МэВ
Большое поле зрения
Хороший тайминг
Запуск 2010 год
Срок работы 5-7 лет
Мониторинг неба в гамма-лучах

21. Isolated BHs Isolated BHs can be detected due to accretion
or due to some exotic emission.
Punsly et al. (astro-ph/ ) predict that
some of EGRET unidentified sources can be
isolated BHs. Corresponding X-ray luminosity
is about erg/s.
astro-ph/

22. Massive NS accreting from WDs
Observations of very massive NSs are important
for EOS studies.
Probably, most massive NSs cannot be observed
as radio pulsars.
astro-ph/

23. Binaries with magnetars - magnetors
Can RCW 103 be a prototype?
6.7 hour period (de Luca et al. 2006)
Possible explanations:
Magnetar, spun-down by disc
Double NS system
Low-mass companion + magnetar=
magnetor
RCW 103

24. Conclusion There are several types of sources: CCOs, M7,
SGRs, AXPs, RRATs ...
Unsolved problems:
1. Are there links?
2. Reasons for diversity
Detectors on-board SRG
can contribute in discovery of new INS and
other interesting objects

25. Main reviews NS basics: physics/0503245 SGRs & AXPs: astro-ph/0406133
Magnetars:
Observations
AXPs astro-ph/
SGR astro-ph/
- Theory astro-ph/
Central compact X-ray
sources in supernova
remnants: astro-ph/
The Magnificent Seven: astro-ph/
RRATs: astro-ph/
Cooling of NSs: astro-ph/
Труды ГАИШ том 72 (2003)

26. Dorothea Rockburne (

27. Magnetorotational evolution of radio pulsars
Spin-down.
Rotational energy is released.
The exact mechanism is
still unknown.

28. Known AXPs Sources Periods, s CXO 010043.1-72 8.0 4U 0142+61 8.7
6.4
CXOU J
10.6
1RXS J
11.0
XTE J
5.5 1E
11.8
AX J
7.0 1E

29. What is special about magnetars?
Link with massive stars
There are reasons to suspect that magnetars are connected to massive stars.
Link to binary stars
There is a hypothesis that magnetars are formed in close binary systems
(astro-ph/ ).
Westerlund 1
The question is still on the list.

30. Close-by radio quiet NSs
Discovery: Walter et al. (1996)
Proper motion and parallax:
Kaplan et al.
No pulsations
Thermal spectrum
Later on:
six brothers
RX J

31. 27 Dec 2004 Giant flare SGR 1806-20 Spike 0.2 s Fluence 1 erg/cm2
E(spike)= erg
L(spike)= erg/s
Long «tail» (400 s)
P=7.65 s
E(tail) erg
Distance 15 kpc

32. SGRs: periods and giant flares
P, s
Giant flares
8.0
5 March 1979
(?)
6.4
18 June 1998
7.5
27 Dec 2004
5.2
27 Aug 1998
New result:
oscillations
in the “tail”.
“Trembling”
of the crust
(Israel et al. 2005,
Watts and Strohmayer 2005).
See the review in
Woods, Thompson
astro-ph/

33. Anomalous X-ray pulsars
Identified as a separate group in 1995.
(Mereghetti, Stella 1995 Van Paradijs et al.1995)
Similar periods (5-10 sec)
Constant spin down
Absence of optical companions
Relatively weak luminosity
Constant luminosity