Isolated Neutron Stars. Intro.
Prediction ...
Neutron stars have been predicted in 30s:
L.D. Landau: Star-nuclei (1932) + anecdote
Baade and Zwicky:
neutron stars and supernovae (1934) (Landau)
(Baade)
(Zwicky)
Shapiro,Teukolsky (1983)
(from lectures by D. Yakovlev)
(see detailed description in the book by Haensel, Yakovlev, Potekhin and
in the e-print arXiv: 1210.0682)
Physikalische
Zeitschrift der Sowjetunion
Vol. 1, No. 2, 285-188, 1932
Written: Feb. 1931, Zurich
Received: Jan. 7, 1932
Published: Feb. 1932
Landau paper BEFORE neutron discovery
This is correct!
Disappered in reprints,
so we have difficulties
Baade and Zwicky – theoretical prediction
W. Baade (Mt. Wilson Observatory)
F. Zwicky (Caltech)
The meeting of American Physical
Society
(Stanford, December 15-16, 1933)
Published in Physical Review
(January 15, 1934)
Phys. Rev. 46, 76, 1934 July 1
Good old classics
The pulsar in the Crab nebula A binary system
For years two main types of NSs have been discussed:
radio pulsars and accreting NSs in close binary systems
The old zoo of neutron stars
In 60s the first X-ray sources have been discovered.
They were neutron stars in close binary systems, BUT ...
.... they were «not recognized»....
Now we know hundreds
of X-ray binaries with
neutron stars in the
Milky Way and in other
galaxies.
Rocket experiments. Sco X-1
Giacconi et al. 1962
In 2002 R. Giacconi
was awarded with the
Nobel prize.
On the photo: Giacconi, Gursky, Hendel
UHURU
The satellite was launched on
December 12, 1970.
The program was ended in
March 1973.
The other name SAS-1
2-20 keV
The first full sky survey.
339 sources.
Accretion in close binaries
Accretion is the most powerful
source of energy
realized in Nature,
which can give a huge
energy output.
When matter fall down
onto the surface of a
neutron star up to 10%
of mc2 can be released.
Accretion disc
The theory of
accretion discs
was developed
in 1972-73 by
N.I. Shakura and
R.A. Sunyaev.
Accretion is
important not only
in close binaries,
but also in
active galactic
nuclei and many
other types of
astrophysical
sources.
Close binary systems
About ½ of massive stars
Are members of close binary
systems.
Now we know many dozens
of close binary systems with
neutron stars.
•
L=Mηc2
The accretion rate can be up to 1020 g/s;
Accretion efficiency – up to 10%;
Luminosity –thousands of hundreds of the solar.
Discovery !!!!
1967: Jocelyn Bell. Radio pulsars.
Seredipitous discovery.
The pulsar in the Crab nebula
SNRs and PSRs
Igoshevetal.2022
There are:
- Young PSRs within SNRs
(see 2110.00179);
- Young PSRs without SNRs
(see 1204.0632);
- SNRs without PSRs
(see 2101.12486)
No PSRs – due to low sensitivity;
No remnants due to the ISM.
Joint studies of NSs and their SNRs are very useful to improve our understanding
of initial parameters and early evolution of compact objects (see e.g., 2104.10052).
TeV halos
1902.08203
Milagro and HAWC
TeV halos are powerd
by electrons and positrons
from PWNe, but their
farther diffusion outside a PWN
is suppressed.
New record:
76 seconds
2206.01346
PSR J0901−4046
MeerKAT observations
Slowly rotating NSs – in binaries
1705.01791
AX J1910.7+0917
P>10 hours! (36200+/-100 sec)
18-minutes PSR period?
Hurley-Walker et al. 2022
Murchison Widefield Array
GLEAM-X J162759.5-523504.3
72–231 MHz
DM=57 ± 1 pc cm−3
d=1.3 ± 0.5 kpc
RM=−61 ± 1 rad m−2
Hurley-Walker et al. 2022
The old Zoo: young pulsars & old accretors
NSs in the Milky Way
2105.04549
During last ~25 years
it became clear that neutron stars
can be born very different.
In particular, absolutely
non-similar to the Crab pulsar.
o High-B PSRs
o Compact central X-ray sources
in supernova remnants.
o Anomalous X-ray pulsars
o Soft gamma repeaters
o The Magnificent Seven
o Transient radio sources (RRATs)
The new zoo of young neutron stars
Old and new zoos: Harding arXiv:1302.0869
See a more recent review in 1712.06040
Compact central X-ray sources in
supernova remnants
Cas A RCW 103
6.7 hour period
(de Luca et al. 2006)
Rapid cooling
(Heinke et al. 1007.4719)
Catalogue of CCOs
http://www.iasf-milano.inaf.it/~deluca/cco/main.htm
+ candidates + RCW103
Anti-magnetars
0911.0093
Star marks the CCO from
0911.0093
1301.2717:
Spins and derivative are
measured for
PSR J0821-4300 and
PSR J1210-5226
“Hidden” magnetars
Halpern,Gotthelf2010
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
A pulsar with growing field?
Espinoza et al. arXiv: 1109.2740
Will it become a magnetar?
PSR J1734−3333
n=0.9+/-0.2
Magnetars
◼ dE/dt > dErot/dt
◼ By definition: The energy of the magnetic field is released
Magnetic fields 1014–1015 G
~30 sources known
Magnetic field estimates
◼ Spin down
◼ Long spin periods
◼ Energy to support
bursts
◼ Field to confine a
fireball (tails)
◼ Duration of spikes
(alfven waves)
◼ Direct measurements
of magnetic field
(cyclotron lines) Ibrahim et al. 2002
Extragalactic SGRs
[D. Frederiks et al. astro-ph/0609544]
It was suggested long ago (Mazets et al. 1982)
that present-day detectors could already detect
giant flares from extragalactic magnetars.
However, all searches in, for example,
BATSE database did not provide good candidates
(Lazzati et al. 2006, Popov & Stern 2006, etc.).
Finally, recently several good candidates
have been proposed by different groups
(Mazets et al., Frederiks et al., Golenetskii et al.,
Ofek et al, Crider ...., see arxiv:0712.1502 and
references therein, for example).
Burst from M31
Recent summary can be found in Burns et al.
ApJ (2021) 2101.05144
Extragalactic hyperflares
2101.05144
Transient radio emission from AXP
(Camilo et al. astro-ph/0605429)
Radio emission was detected from XTE J1810-197
during its active state.
Clear pulsations have been detected.
Large radio luminosity.
Strong polarization.
Precise Pdot measurement.
Important to constrain models, for better distance
and coordinates determinations, etc.
ROSAT and XMM images
an X-ray outburst
happened in 2003.
AXP has spin period 5.54 s
Recent radio data on this source: 1903.02660
Another AXP detected in radio
1E 1547.0-5408
P= 2 sec
SNR G327.24-0.13
0802.0494 (see also arxiv:0711.3780 )
Pdot changed significantly on the scale of just
~few months
Rotation and magnetic axis seem to be aligned
Also this AXP demonstrated weak
SGR-like bursts (Rea et al. 2008, GCN 8313)
Radio
X-rays
[simultaneous]
Short radio pulses from magnetars
2005.08410
XTE 1810
1E 1547.0–5408
2011.06607
1908.04304
Transient radiopulsar
PSR J1846-0258
P=0.326 sec
B=5 1013 G
0802.1242, 0802.1704
Among all rotation powered
PSRs it has the largest Edot.
Smallest spindown age (884 yrs).
The pulsar increased
its luminosity in X-rays.
Increase of pulsed X-ray flux.
Magnetar-like X-ray bursts (RXTE).
Timing noise.
See additional info about this pulsar
at the web-site
http://hera.ph1.uni-koeln.de/~heintzma/SNR/SNR1_IV.htm
However,
no radio emission
detected.
Due to beaming?
Bursts from the transient PSR
Gavriil et al. 0802.1704
Chandra: Oct 2000 June 2006
Weak dipole field magnetar
Old magnetar ? (1107.5488)
B<7.5 1012 G (arXiv:1010.2781)
Spin period of a neutron star grows.
The rate of deceleration is related to the dipole magnetic field.
Measuring the spin-down rate we measure the field.
The source is a soft gamma-ray
repeater: SGR 0418+5729
P=9.1 s
The straight line in the plot
corresponds to a constant
spin periods: i.e. no spin-down
200 400
Spectral data suggests high field on the surface: 1103.3024
Another low field magnetar
1203.6449
Swift J1822.3-1606 (SGR 1822-1606)
1204.1034
P=8.44 s
B=3-5 1013 G
New data: 1211.7347
One more low-field magnetar
1311.3091
3XMM J185246.6+003317
P=11.5 s No spin-down detected after 7 months
B<4 1013 G
Transient magnetar
RCW103 – a special kind of magnetar
1904.05424
Looked like a CCO
6.7 hours spin period!
SGR-like bursts.
Quiescent magnetar J1622–4950
arXiv: 1007.1052
Normally, magnetars are detected via their
strong activity: gamma-ray bursts or
enhanced X-ray luminosity.
This one was detected in radio observations
The field is estimated to be B~3 1014 G
It seems to be the first magnetar to be
Detected in a quiescent state.
PSR J1622–4950 was detected in a radio survey
As a pulsar with P=4.3 s.
Noisy behavior in radio
Chandra
ATCA
See reviews on high-B PSRs in 1010.4592, 1805.01680
Is J1622–4950 a transient magnetar?
1203.2719
PSR J1622–4950
X-ray flux is decaying
for several years.
Probably, the source
was active years before.
G333.9+0.0 SNR ?
See also 1204.2045
Yes! Revival of J1622–4950
1804.01933 Among few (~5) magnetars with detected radio emission.
ROSAT
ROentgen SATellite
Launched 01 June 1990.
The program was successfully ended
on 12 Feb 1999.
German satellite
(with participation of US and UK).
Close-by radioquiet NSs
◼ Discovery: Walter et al.
(1996)
◼ Proper motion and
distance: Kaplan et al.
◼ No pulsations
◼ Thermal spectrum
◼ Later on: six brothers
RX J1856.5-3754
Magnificent Seven
Name Period, s
RX 1856 7.05
RX 0720 8.39
RBS 1223 10.31
RBS 1556 -----
RX 0806 11.37
RX 0420 3.45
RBS 1774 9.44
Radioquiet
Close-by
Thermal emission
Absorption features
Long periods
For RBS 1556 (RX J1605) the period is uncertain: 1901.08533, 1906.02806
1401.7147
Several radio pulsars can be similar to M7.
E.g. PSR J0726−2612 (see 1906.01372).
Radio observations
Kondratiev et al. arXiv: 0907.0054
Up to now the M7 are not detected for sure at radio wavelengths,
however, there was a paper by Malofeev et al., in which the authors
claim that they had detect two of the M7 at very low wavelength (<~100 MHz).
At the moment the most strict limits are given by Kondratiev et al.
Non-detection is still consistent with narrow beams.
Spectral properties
KaplanarXiv:0801.1143
Spectra are blackbody plus one or several wide
absorption features.
The origin of features is not understood, yet.
VanKerkwijketal.(2004)
New data: Kaplan et al. 1105.4178
Possible hard X-ray excesses are reported
for two out of the M7: 1910.02956.
Hard X-ray excess in RX J1856
2209.03874
Calvera et al.
In 2008 Rutledge et al. reported the discovery of an enigmatic
NS candidated dubbed Calvera. It is high above the galactic plane.
Shevchuk et al. arXiv: 0907.4352
Possible discovery of Calvera's supernova remnant 2207.14141
More data on Calvera
XMM-Newton observations. Zane et al. arXiv: 1009.0209
Thermal emission (two blackbody or two atmospheric: ~55/150 eV and ~80/250 eV)
P=0.06 sec
Pdot =3.2 10-15 (B=4.4 1011 G)
No radio emission
Not detected by Fermi
New data 1510.00683, 1902.00144, 2110.14930
1310.6789
The isolated neutron star candidate
2XMM J104608.7-594306
Pires & Motch arXiv: 0710.5192 and Pires et al. arXiv: 0812.4151
A new INS candidate.
B >26, V >25.5, R >25
(at 2.5σ confidence level)
log(FX/FV) >3.1
kT = 118 +/-15 eV
unabsorbed X-ray flux:
Fx ~1.3 10−12 erg s−1 cm−2
in the 0.1–12 keV band.
At 2.3 kpc (Eta Carina)
the luminosity is
LX ~ 8.2 1032 erg s−1
R∞ ~ 5.7 km
M7-like? Yes!
But P=19 msec
Spin period of 2XMM J1046-5943
1508.05246
Calvera-like?
M7 among other NSs
Evolutionary links of M7
with other NSs are not
clear, yet.
M7-like NSs can be
numerous.
They can be descendants
of magnetars.
Can be related to RRATs.
Or, can be a different
population.
Pires et al. (2015), A&A
How to find new candidates?
1. Digging the data
Many attempts failed. One of the latest used SDSS optical data together
with ROSAT X-ray. Candidates have been observed by Chandra.
Nothing was found (Agueros et al. arXiv: 1103.2132).
2. eROSITA is in orbit!
In 2019 spectrum-RG with eROSITA was launched.
It is expected that with this telescope tens of
new M7-like NSs can be found (Boldin et al., Pires et al.)
Pulsars invisible in radio?
(Grenier astro-ph/0011298)
(Nolan et al. astro-ph/9607079)
EGRET data
Many unidentified sources
Fermi pulsars
1211.3726
In the 2nd catalogue
there are 117 pulsars.
1/3 mPSR
The rest are young:
1/3 radio-loud
1/3 radio-quiet
Full 2nd catalogue is presented in 1305.4385
In the 3rd catalogue there are 167 pulsars
https://fermi.gsfc.nasa.gov/ssc/data/access/lat/4yr_catalog/3FGL-table/
Discovery of
radio transients
McLaughlin et al. (2006) discovered a new type of sources– RRATs
(Rotating Radio Transients).
For most of the sources periods about few seconds were discovered.
The result was obtained during the Parkes survey of the Galactic plane.
Burst duration 2-30 ms, interval 4 min-3 hr
Periods in the range 0.4-7 s
>100 sources known.
Thermal X-rays were observed from one of the RRATs
(Reynolds et al. 2006). This one seems to me the youngest.
Review: 1109.6896
Catalogue: http://www.as.wvu.edu/~pulsar/rratalog/
RRATs. X-ray + radio data
arXiv: 0710.2056
X-ray pulses overlaped on
radio data of RRAT J1819-1458.
RRAT – are pulsars?
Vela
PSR
J1646–6831
J1647–36
J1226–32
1212.1716
It looks like RRATs bursts are just some kind of magnetospheric activity.
Some PSRs have similar bursts.
It is not easy to plot a boarder line between RRATs and PSRs.
RRATs properties
RRATs with P-Pdot
seem to be
similar to PSRs
About low-frequency
detection see
1807.07565.
1503.05170 Catalogue: http://astro.phys.wvu.edu/rratalog
>100 now, see 1706.08412
LIGO search for GW from PSRs
1902.08442
The ellipticity measures
the degree of asymmetry of the star
with respect to its rotation axis.
LIGO results
1902.08442
Second run
33 PSRs studied.
The labels “AG” and “ BG”
refers to a search
performed after or before
the glitch of a given pulsar.
LIGO search for GW from PSRs
1902.08507
221 PSRs
data from 2015-2017
Limits on ellipticity
1902.08507
Blind search for GWs from NSs
1903.01901, new results in 2107.00600 and 2201.00697
Pulsars, positrons, PAMELA
[Dan Hooper et al. 2008
arXiv: 0810.1527]
[O. Adriani et al.] arXiv:0810.4995
Geminga, PSR B0656+14, and all PSRs
NS birth rate
Keane, Kramer 2008, arXiv: 0810.1512
Too many NSs???
Keane, Kramer 2008, arXiv: 0810.1512
It seems, that the total birth rate is larger than the rate of CCSN.
e- - capture SN cannot save the situation, as they are <~20%.
Note, that the authors do not include CCOs.
So, some estimates are wrong, or some sources evolve into others.
See also astro-ph/0603258. GRAND UNIFICATION: 1005.0876
Conclusion
◼ There are several types of
sources: CCOs, M7,
SGRs, AXPs, RRATs ...
◼ Magnetars
◼ Significant fraction of all
newborn NSs are not similar
to the Crab pulsar
◼ Unsolved problems:
1. Are there links?
2. Reasons for diversity
Some reviews on isolated neutron stars
• NS basics: physics/0503245
astro-ph/0405262
• Thermal emission 1507.06186
• Magnetars: 1507.02924
• Magnetar bursts: arXiv: 1101.4472
• CCOs: astro-ph/0311526
arxiv:0712.2209
• Quark stars: arxiv:0809.4228
• The Magnificent Seven: astro-ph/0609066
arxiv:0801.1143
• RRATs: arXiv:1008.3693
• Cooling of NSs: astro-ph/0402143
• NS structure arXiv:0705.2708
• EoS arXiv: 1001.3294
1512.07820
• NS atmospheres 1403.0074
• NS magnetic fields arxiv:0711.3650
•Different types arXiv:1005.0876
arXiv:1302.0869
arXiv: 1712.06040
•Radio pulsars 1602.07738
Read the OVERVIEW in the book by Haensel, Yakovlev, Potekhin
Lectures can be found
at my homepage:
http://xray.sai.msu.ru/~polar/
html/presentations.html
• Internal structure
and astrophysics 1603.02698
• SN and compact remnants 1806.07267