Searching Potential X-Searching Potential X-Ray Counterparts of GeRay Counterparts of GeV Sources J1837-0610V Sources J1837-0610

盧亭霓盧亭霓 Lu Ting-NiLu Ting-Ni

2006.11.21 2006.11.21

OutlineOutline• Introduction - Science purpose - GeV J1837-0610 • Data - download data - data reduction - analysis• Results• Conclusion• Reference

IntroductionIntroduction• Science purpose - try to find next γ-ray pulsar.

• Gev J1837-0610 - an unidentified γ-ray source. - with a X-ray counterpart candidate AX J1837.5-0610 (Roberts M. S. E. et al, 2001, ApJS, 133, 451-456).

Roberts M. S. E. et al, 2001, ApJS, 133, 451-456

Roberts M. S. E. et al, 2001, ApJS, 133, 451-456

IntroductionIntroduction• GeV J1837-0610

Roberts M. S. E. et al, 2001, ApJS, 133, 451-456

DataData• Download data - constrain: a. center offset < 25 arcmin. b. exposure time > 10 ksec.

DataData• Download data

Satellite name

ROSAT ASCA BeppoSax

MissionID

RP500204N00

26013000 26013010 21190001 211900011

Obs. date 1993.04.08

1998.04.02 1998.10.18 2001.03.12 2001.04.17

Exposure time (s)

19986 SIS18752

GIS21376

SIS18496

GIS 20256

LECS13494

MECS40060

LECS20039

MECS42605

DataData• Data reduction - abandon ROSAT data: cannot find any point-like source near the area with RA~18h37m, Dec~-06h10m.

The green circle is the region with center at (RA, Dec)=(18:37:29.000,-6:09:38.000), radius=90arcsec.

DataData• Data reduction - abandon SIS data of ASCA: there’s only FAST mode data can be used to do timing analysis, but the FAST mode data isn’t offered by the archieve data.

- abadon LECS data of Beppo-SAX: the exposure time is too short. Also, there’s not any point-like source near the area with RA~18h37m, Dec~-06h10m

DataData

Satellite name

ASCA BeppoSax

MissionID

26013000 26013010 21190001 211900011

Obs. date 1998.04.02 1998.10.18 2001.03.12 2001.04.17

Exposure time (s)

GIS21376

GIS 20256

MECS40060

MECS42605

Expansion time (s)

~37.3k ~40.1k ~94.5k ~105.1k

• Data reduction

DataData• Data reduction - filter region and determine position: a. ASCA: *The point spread function (PSF) of GIS alone is a Gaussian with a FWHM of 0.5×(5.9/E 〔 keV 〕 ) arcmin. *The main energy band of the photons is at between 2.3keV and 7.1keV.

The corresponds of the PI channel of ASCA to the energy band.

DataData• Data reduction - filter region and determine position: b. BeppoSAX:

Originated from the cookbook for BeppoSAX NFI spectral analysis V1.2

Originated from the cookbook for BeppoSAX NFI spectral analysis V1.2

The corresponds of the PI channel of BeppoSAX to the energy band.

DataData• Data reduction - filter region and determine position: besides, the region need to encloses the most photons of source but least photons of background.

DataData

• Data reduction - filter energy: a. ASCA:

http://heasarc.gsfc.nasa.gov/docs/asca/gis_sis_effective_area.html

DataData

• Data reduction - filter energy: b. BeppoSAX:

Originated from the cookbook for BeppoSAX NFI spectral analysis V1.2

DataData

Satellite name ASCA Beppo-SaxMission ID 26013000 26013010 21190001 211900011

Obs. date 1998.04.02 1998.10.18 2001.03.12 2001.04.17

Position (RA.Dec) (18:37:29.000,-6:09:38.000) (18:37:32.500,-06:09:49.000)

Radius of region (arcsec)

90 210

Energy band 2-10 keV 2-10 keV

DataData• Data reduction - barycentric time correction: to make the time on satellite be accordance with the time on earth.

Left: before doing barycentric time correction; Right: after doing barycentric time correction.

Example of ASCA data(1998-04-02)

DataData• Analysis - a. epoch folding. b. Zm2-Test. c. H-Test.

DataData

Satellite name ASCA BeppoSaxMission ID 26013000 26013010 21190001 211900011

Obs. date 1998.04.02 1998.10.18 2001.03.12 2001.04.17

Exposure time (s) GIS21376

GIS 20256

MECS40060

MECS42605

Expansion time (s) ~37.3k ~40.1k ~94.5k ~105.1k

Number of photons 205 163 739 770

Search frequency (Hz)

(0.01, 10) (0.01, 10) (0.01, 100) (0.01, 100)

DataData1998/04/2 　 　 2001/03/12 　 　MJD=5.090553135e+04 　 MJD=5.198125968e+04 　T=37.3 (ks) 　 　 T=94.5 (ks) 　 　

ASCA Period (s)

H value r.p. BeppoSAX Period (s) H value r.p.

0.468115 3.77E+0

19.58E-

071.921297

4.36E+01

1.91E-07

1.133890 3.51E+0

12.05E-

0628.453860

4.46E+01

1.48E-07

3.835480 3.59E+0

11.62E-

0632.594138

4.12E+01

3.61E-07

4.098285 3.99E+0

15.16E-

0739.523627

4.63E+01

9.67E-08

6.487490 3.95E+0

15.76E-

0755.713702

4.13E+01

3.52E-07

6.487495 3.60E+0

11.57E-

0656.907721

4.54E+01

1.21E-07

1998/10/18 　 　 2001/04/17 　 　MJD=5.110510478e+04 　 MJD=5.201665630e+04 　T=40.1 (ks) 　 　 T=105.1 (ks) 　 　

ASCA Period (s)

H value r.p. BeppoSAX Period (s) H value r.p.

3.745875 4.27E+0

12.42E-

075.4447178

4.32E+01

2.12E-07

6.964355 4.07E+0

14.14E-

0727.8330645

4.33E+01

2.07E-07

8.000580 5.15E+0

14.00E-

0849.4017113

4.37E+01

1.87E-07

　 　 　 55.5315288 4.32E+0

12.12E-07

　 　 　 69.1390553 4.38E+0

11.82E-07

　 　 　 98.2426908 4.68E+0

18.55E-08

Trial periods at which H value is larger than about 35

DataData• Analysis - search counterpart periods of data: use the condition that the age of a pulsar should be larger than 1000 years to find possible periods in other data (which is observed at different time).

ResultResult

　 date period (s)H value

date

counterpart

period (s)

H value

dp/dt (10-13 s/

s) 　

P1

2001/04/17

0.0144636052

43.82001/03

/120.0144630

248 23.6 1.898

P2

2001/03/12

0.0306803632

41.22001/04

/170.0306809

504 21.7 1.920

P3

1998/04/02

0.2607236 35.92001/04

/170.2607847

1 23.5 6.369

P4

1998/10/18

0.2669603 42.72001/04

/170.2672506

622.4 36.864

P5

2001/03/12

0.5204817 43.61998/10

/180.5200600 20.1 55.699

P6

1998/04/02

2.13623 37.72001/04

/172.139328 19.1

323.046

Tentative counterpart periods in ASCA and BeppoSAX data

Periods are reported with digits accurate to about one tenth of corresponding Fourier widths. The random probability (r.p.) is for one single trial only.

ResultResult

　 period (s)Τc (year)

　

dp/dt (10-13 s/s)

　S.P.E.

(erg s-1)B field

(G)

P10.01446360

52 1207 1.898

2.48E+39

1.68E+12

P20.03068036

32 2531 1.920

2.63E+38

2.46E+12

P3 0.2607236 6486 6.369 1.42E+3

61.30E+1

3

P4 0.2669603 1148 36.864 7.64E+3

63.18E+1

3

P5 0.5204817 1480 55.699 1.56E+3

65.45E+1

3

P6 2.13623 1048 323.04

6 1.31E+3

52.66E+1

4

Properties of the six tentative counterpart periods

Periods are reported with digits accurate to about one tenth of corresponding Fourier widths. Here used the period that has larger H value. The Τc is the characteristic age and equals to P/2P’. S.P.E. is the spin downenergy .

Comparison between the six tentative counterpart periods and the high energy pulsar

ConclusionConclusion• Age: the age of Crab is about 1300 years, but P1, P4 and P6 is young than Crab.• Period: the period of existent γ-ray pulsar is at the scale of millisecond, but P6 has period of 2 seconds.• S.P.E.: the S.P.E. of existent γ-ray pulsar is about 1034~1038 (erg s-1), but the S.P.E. of P1 is about 1039 (erg s-1).• Compare with existent γ-ray pulsar, I thought P2 is

more possible period within the six case, and infered from above that Gev J1837-0610 may be a crab-like pulsar.

ReferenceReference• Roberts M. S. E., et al, 2001, ApJS, 133, 451-456• Gottfried Kanbach, 2002, 2002nsps. Conference• P. M. Wallace and N. J. Griffis, et al, 2000, APJ, 540: 184-191• M. Tavani, et al, 1997, APJ, 479: L109-L112• Takanori Sakamoto, 2001, 2001ASPC, Vol. 251• http://www.atnf.csiro.au/research/pulsar/psrcat/• http://heasarc.gsfc.nasa.gov/docs/asca/gis_sis_effective_ar

ea.html

THANK YOU VERY

MUCH~~~!!