Transcript Close-by young isolated neutron stars (and black holes)

Solar vicinity,
close-by young isolated NSs,
and tests of cooling curves
Sergei Popov
(Sternberg Astronomical Institute)
Co-authors: H.Grigorian, R. Turolla, D. Blaschke
ECT*, Trento, September 14, 2005
Plan of the talk
 Intro. Close-by NSs
 Age-Distance diagram
 Solar vicinity. Stars
 Spatial distribution
 Mass spectrum
 Two tests of cooling
 Brightness constraint
 Sensitivity of two tests
 Final conclusions
2
Isolated neutron stars population:
in the Galaxy and at the backyard
 INSs appear in many flavours
 Radio pulsars
 AXPs
 SGRs
Note a recent discovery
by Lyne et al. (submited
 CCOs
to Nature, see later)
 RINSs
 Local population of young NSs
is different (selection)
Radio pulsars
Geminga+
RINSs
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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
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Magnificent Seven
Name
Period, s
RX 1856
-
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
Long periods
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Population of close-by young NSs
 Magnificent seven
 Geminga and 3EG J1853+5918
 Four radio pulsars with thermal emission
(B0833-45; B0656+14; B1055-52; B1929+10)
 Seven older radio pulsars, without detected
thermal emission.
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Age-distance diagram
A toy-model: a local
sphere (R=300 pc)
and a flat disk.
Rate of NS formation
in the sphere is
235 Myr-1 kpc-3
(26-27 NS in Myr in
the whole sphere).
Rate in the disc is
10 Myr-1 kpc-2
(280 NS in Myr up to
3 kpc).
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(astro-ph/0407370)
More realistic age-dist. diagram
Initial distribution
from Popov et al. 2005.
Spatial evolution is not
followed.
For the line of “visibility”
(solid line in the middle)
I assume the limiting
flux 10-12 erg s-1 cm-2
and masses are <1.35
(Yakovlev et al. curves).
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Realistic age-distance diagram
Realistic initial distribution.
Spatial evolution is taken
into account.
The line of “visibility” is
drawn as the dotted line.
Five curves correspond to
1, 4 , 13, 20 and 100 NSs.
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Solar vicinity
 Solar neighborhood is not a

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
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

typical region of our Galaxy
Gould Belt
R=300-500 pc
Age: 30-50 Myrs
20-30 SN per Myr (Grenier 2000)
The Local Bubble
Up to six SN in a few Myrs
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The Gould Belt
 Poppel (1997)
 R=300 – 500 pc
 Age 30-50 Myrs
 Center at 150 pc from
the Sun
 Inclined respect to the
galactic plane at 20
degrees
 2/3 massive stars in
600 pc belong to the
Belt
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Distribution of open clusters
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(Piskunov et al. astro-ph/0508575)
Surface density of open clusters
(Piskunov et al.)
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Spatial distribution of close-by
open clusters in 3D
Grey contours show
projected density
distribution of young
(log T<7.9) clusters.
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(Piskunov et al.)
Clusters and absorption
Triangles –
Gould Belt clusters.
(Piskunov et al.)
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Spatial distribution
More than ½ are in
+/- 12 degrees from
the galactic plane.
19% outside +/- 30o
12% outside +/- 40o
(Popov et al. 2005
Ap&SS 299, 117)
Lyne et al. reported transient dim radio sources with possible periods
about seconds in the galactic plane discovered in the Parkes survey
(talk by A. Lyne in Amsterdam, august 2005; subm. to Nature).
Shall we expect also Lyne’s objects from the Belt????
YES!!! And they even have to be brighter (as they are closer).
The problem – low dispersion.
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Mass spectrum of NSs
 Mass spectrum of local
young NSs can be
different from the
general one (in the
Galaxy)
 Hipparcos data on
near-by massive stars
 Progenitor vs NS mass:
Timmes et al. (1996);
Woosley et al. (2002)
(masses of secondary objects in NS+NS)
astro-ph/0305599
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Two tests
Age – Temperature
&
Log N – Log S
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Standard test: temperature vs. age
Kaminker et al. (2001)
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Log of the number of sources
brighter than the given flux
Log N – Log S
calculations
-3/2 sphere:
number ~ r3
flux
~ r-2
-1 disc:
number ~ r2
flux
~ r-2
Log of flux (or number counts)
20
Log N – Log S as an additional test
 Standard test: Age – Temperature
 Sensitive to ages <105 years
 Uncertain age and temperature
 Non-uniform sample
 Log N – Log S
 Sensitive to ages >105 years
(when applied to close-by NSs)
 Definite N (number) and S (flux)
 Uniform sample
 Two test are perfect together!!!
astro-ph/0411618
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List of models (Blaschke et al. 2004)
Blaschke et al. used 16
sets of cooling curves.
They were different in
three main respects:
1. Absence or presence
of pion condensate
2. Different gaps for
superfluid protons and
neutrons
3. Different Ts-Tin
Pions Crust
 Model I.








Yes
Model II. No
Model III. Yes
Model IV. No
Model V. Yes
Model VI. No
Model VII. Yes
Model VIII.Yes
Model IX. No
C
D
C
C
D
E
C
C
C
Gaps
A
B
B
B
B
B
B’
B’’
A
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Model I
 Pions.
 Gaps from Takatsuka & Tamagaki
(2004)
 Ts-Tin from Blaschke, Grigorian,
Voskresenky (2004)
Can reproduce observed Log N – Log S
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Model II
 No Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Tsuruta (1979)
Cannot reproduce observed Log N – Log S
24
Model III
 Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Blaschke,
Grigorian, Voskresenky (2004)
Cannot reproduce observed Log N – Log S
25
Model IV
 No Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Blaschke, Grigorian,
Voskresenky (2004)
Cannot reproduce observed Log N – Log S
26
Model V
 Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Tsuruta (1979)
Cannot reproduce observed Log N – Log S
27
Model VI
 No Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Yakovlev et al.
(2004)
Cannot reproduce observed Log N – Log S
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Model VII
 Pions
 Gaps from Yakovlev et
al. (2004), 3P2 neutron
gap suppressed by 0.1.
1P proton gap
0
suppressed by 0.5
 Ts-Tin from Blaschke,
Grigorian, Voskresenky
(2004)
Cannot reproduce observed Log N – Log S
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Model VIII
 Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1. 1P0
proton gap suppressed by
0.2 and 1P0 neutron gap
suppressed by 0.5.
 Ts-Tin from Blaschke,
Grigorian, Voskresenky
(2004)
Can reproduce observed Log N – Log S
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Model IX
 No Pions
 Gaps from Takatsuka &
Tamagaki (2004)
 Ts-Tin from Blaschke,
Grigorian, Voskresenky
(2004)
Can reproduce observed Log N – Log S
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HOORAY!!!!
Log N – Log S can select models!!!!!
Only three (or even one!) passed the second test!
…….still………… is it possible just to update
the temperature-age test???
May be Log N – Log S is not necessary?
Let’s try!!!!
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Brightness constraint
 Effects of the crust
(envelope)
 Fitting the crust it is
possible to fulfill the
T-t test …
 …but not the
second test:
Log N – Log S !!!
(H. Grigorian astro-ph/0507052)
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Sensitivity of Log N – Log S
 Log N – Log S is very sensitive to gaps
 Log N – Log S is not sensitive to the crust if it is
applied to relatively old objects (>104-5 yrs)
 Log N – Log S is not very sensitive to presence or
absence of pions
Model I (YCA) Model II (NDB) Model III (YCB)
Model IV (NCB) Model V (YDB) Model VI (NEB)
Model VII(YCB’) Model VIII (YCB’’) Model IX (NCA)
We conclude that the two test complement each other
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THAT’S ALL. THANK YOU!
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Resume
 We live in a very interesting region of the Milky
Way!
 Log N – Log S test can include NSs with
unknown ages, so additional sources
(like the Magnificent Seven) can be used
to test cooling curves
 Two tests (LogN–LogS and Age-Temperature)
are perfect together.
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Radio detection
Malofeev et al. (2005) reported detection of
1RXS J1308.6+212708 (RBS 1223)
in the low-frequency band (60-110 MHz)
with the radio telescope in Pushchino.
(back)
37
Evolution of NS:
spin + magnetic field
Ejector → Propeller → Accretor → Georotator
1 – spin-down
2 – passage through a molecular cloud
3 – magnetic field decay
Lipunov (1992)
astro-ph/0101031
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Model I
 Pions.
 Gaps from Takatsuka & Tamagaki
(2004)
 Ts-Tin from Blaschke, Grigorian,
Voskresenky (2004)
Can reproduce observed Log N – Log S
(back)
39
Model IX
 No Pions
 Gaps from Takatsuka &
Tamagaki (2004)
 Ts-Tin from Blaschke,
Grigorian, Voskresenky
(2004)
Can reproduce observed Log N – Log S
(back)
40
Model III
 Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Blaschke,
Grigorian, Voskresenky (2004)
Cannot reproduce observed Log N – Log S
(back)
41
Model II
 No Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Tsuruta (1979)
Cannot reproduce observed Log N – Log S
(back)
42
Model IV
 No Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Blaschke, Grigorian,
Voskresenky (2004)
Cannot reproduce observed Log N – Log S
(back)
43
Model V
 Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Tsuruta (1979)
Cannot reproduce observed Log N – Log S
(back)
44
Model VI
 No Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1
 Ts-Tin from Yakovlev et al.
(2004)
Cannot reproduce observed Log N – Log S
(back)
45
Model VII
 Pions
 Gaps from Yakovlev et
al. (2004), 3P2 neutron
gap suppressed by 0.1.
1P proton gap
0
suppressed by 0.5
 Ts-Tin from Blaschke,
Grigorian, Voskresenky
(2004)
Cannot reproduce observed Log N – Log S
(back)
46
Model VIII
 Pions
 Gaps from Yakovlev et al.
(2004), 3P2 neutron gap
suppressed by 0.1. 1P0
proton gap suppressed by
0.2 and 1P0 neutron gap
suppressed by 0.5.
 Ts-Tin from Blaschke,
Grigorian, Voskresenky
(2004)
Can reproduce observed Log N – Log S
(back)
47
NS+NS binaries
Pulsar
B1913+16
B2127+11C
B1534+12
J0737-3039
J1756-2251
Pulsar mass
Companion mass
1.44
1.35
1.33
1.34
1.40
1.39
1.36
1.35
1.25
1.18
(PSR+companion)/2
J1518+4904
J1811-1736
J1829+2456
1.35
1.30
1.25
(David Nice, talk at Vancouver)
(Back)
48
P-Pdot for new transient sources
Lyne et al. 2005
Submitted to Nature
(I’m thankful to
Prof. Lyne for giving
me an opportunity
to have a picture
in advance)
Estimates show that
there should be about
400 000
sources of this type
in the Galaxy
(back)
49