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Solar vicinity, close-by young isolated NSs, and tests of cooling curvesPowerPoint Presentation

Solar vicinity, close-by young isolated NSs, and tests of cooling curves

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### 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

Isolated neutron stars population: in the Galaxy and at the backyard

- INSs appear in many flavours
- Radio pulsars
- AXPs
- SGRs
- CCOs
- RINSs

Note a recent discovery

by Lyne et al. (submited

to Nature, see later)

- Local population of young NSs
is different (selection)

- Radio pulsars
- Geminga+
- RINSs

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

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.

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).

(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).

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.

Solar vicinity

- Solar neighborhood is not a 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

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

Distribution of open clusters

(Piskunov et al. astro-ph/0508575)

Surface density of open clusters

(Piskunov et al.)

Spatial distribution of close-by open clusters in 3D

Grey contours show

projected density

distribution of young

(log T<7.9) clusters.

(Piskunov et al.)

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.

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

Standard test: temperature vs. age

Kaminker et al. (2001)

Log N – Log S

calculations

-3/2 sphere:

number ~ r3

flux ~ r-2

Log of the number of sources

brighter than the given flux

-1 disc:

number ~ r2

flux ~ r-2

Log of flux (or number counts)

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

- Sensitive to ages >105 years
- Two test are perfect together!!!

astro-ph/0411618

Model II. No D B

Model III. Yes C B

Model IV. No C B

Model V. Yes D B

Model VI. No E B

Model VII. Yes C B’

Model VIII.Yes C B’’

Model IX. No C A

Blaschke et al. used 16 sets of cooling curves.

They were different in three main respects:

Absence or presence of pion condensate

Different gaps for superfluid protons and neutrons

Different Ts-Tin

List of models (Blaschke et al. 2004)Pions Crust Gaps

Model I

- Pions.
- Gaps from Takatsuka & Tamagaki (2004)
- Ts-Tin from Blaschke, Grigorian, Voskresenky (2004)

Can reproduce observed Log N – Log S

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

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

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

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

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

Model VII

- Pions
- Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1.
1P0 proton gap suppressed by 0.5

- Ts-Tin from Blaschke, Grigorian, Voskresenky (2004)

Cannot reproduce observed Log N – Log S

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

Model IX

- No Pions
- Gaps from Takatsuka & Tamagaki (2004)
- Ts-Tin from Blaschke, Grigorian, Voskresenky (2004)

Can reproduce observed Log N – Log S

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!!!!

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)

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

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.

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)

Evolution of NS: spin + magnetic field

Ejector → Propeller → Accretor → Georotator

1 – spin-down

2 – passage through a molecular cloud

3 – magnetic field decay

astro-ph/0101031

Lipunov (1992)

Model I

- Pions.
- Gaps from Takatsuka & Tamagaki (2004)
- Ts-Tin from Blaschke, Grigorian, Voskresenky (2004)

Can reproduce observed Log N – Log S

(back)

Model IX

- No Pions
- Gaps from Takatsuka & Tamagaki (2004)
- Ts-Tin from Blaschke, Grigorian, Voskresenky (2004)

Can reproduce observed Log N – Log S

(back)

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)

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)

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)

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)

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)

Model VII

- Pions
- Gaps from Yakovlev et al. (2004), 3P2 neutron gap suppressed by 0.1.
1P0 proton gap suppressed by 0.5

- Ts-Tin from Blaschke, Grigorian, Voskresenky (2004)

Cannot reproduce observed Log N – Log S

(back)

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)

NS+NS binaries

Pulsar Pulsar mass Companion mass

B1913+16 1.44 1.39

B2127+11C 1.35 1.36

B1534+12 1.33 1.35

J0737-3039 1.34 1.25

J1756-2251 1.40 1.18

(PSR+companion)/2

J1518+4904 1.35

J1811-1736 1.30

J1829+2456 1.25

(David Nice, talk at Vancouver)

(Back)

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)

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