Searching for Radio Pulsars in
Unidentified Fermi-LAT BrightSources

Scott Ransom (NRAO)
For the Fermi Pulsar SearchConsortium (PSC)

Fermi Bright Source List
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205 sources after 3
months at >10σ
Many withassociations
Many new pulsars
Many without
associations might
be new pulsars
Blind searching in γrays is getting muchharder...

Abdo et al, 2009, ApJS, 183, 46

Why search for pulsars?
●Radio and γ-rays comefrom different parts ofmagnetosphere
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●Constrain emission
See work by Romani,Harding, Gonthier, etcDispersion Measure
gives a distanceRadio timing typicallymuch more accurate
Some pulsars we can't
find in γ-rays

Searches for γ-ray PSRs in EGRET srcs
were not very successful. Exceptions:
PSR J2229+6114 (Halpern et al 2001)
PSR J2021+3651 (Roberts et al 2002)

Which BSL Sources?
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Chose 27 sources:●

No associations●

Not flagged as variable

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Not already deeply
searched in radio
Dec > -40deg
8 sources at highgalactic latitude

30 hrs of GBT time●

Used 9-month posns●

Obs finished 2 wks ago

95% conf. regions wellmatched to 820MHz GBTbeam, 15' in diameter
100-m Green Bank Telescope

Observations and Data Analysis●●

Each src obs ~1 hour●

GBT+GUPPI @ 820MHz●

2048 freq channels●

61μs sampling●

200MHz of bandwidth●~110 GB / src●~3 TB total

Compute Intensive●●

Search over Dispersion Measure, frequency, andpotential orbital (linear) acceleration
Requires ~2 days on 50 CPUs per source

Results so far....
●9 sources have been searched fullyResults so far....
●●9 sources have been searched fully
5 of them are in the Galactic plane and nothing
was seenResults so far....
●●●9 sources have been searched fully
5 of them are in the Galactic plane and nothing
was seen
4 are high-Galactic latitude sources..
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0FGL J1311.9-3419 had nothingResults so far....
●●●9 sources have been searched fully
5 of them are in the Galactic plane and nothing
was seen
4 are high-Galactic latitude sources..
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0FGL J1311.9-3419 had nothing
0FGLs J2214.8+3002, J1231.5-1410, and J0614.33330 each have bright binary millisecond pulsars!

0FGL J2214.8+3002 is PSR J2214+30
3.12 ms spin
10 hr orbit
13 Mjup mincompanion~1.5 kpc (DM)
X-ray point
sources...
Very bright
Scintillation
Arecibo visible!

“Black-Widow”, NANOGrav MSP?

0FGL J2214.8+3002 is PSR J2214+30
3.12 ms spin
10 hr orbit
13 Mjup mincompanion~1.5 kpc (DM)
X-ray point
sources...
Very bright
Scintillation
Arecibo visible!

Chandra ACIS

0FGL J1231.5-1410 is PSR J1231-14
3.68 ms spin
1.86 day orbit
0.2 Msun mincompanion~400 pc (DM)Good X-raypoint source...
(thanks toMichael Wolff)“Normal” Binary MSP (and close)

0FGL J1231.5-1410 is PSR J1231-14
3.68 ms spin
1.86 day orbit
0.2 Msun mincompanion~400 pc (DM)Good X-raypoint source...
(thanks toMichael Wolff)
XMM-Newton (MOS)0FGL J0614.3-3330 is PSR J0614-33
3.15 ms spin
unknown orbit~2 kpc (DM)
X-ray point
sources...
Very bright
Scintillation

Unknown Binary MSP

0FGL J0614.3-3330 is PSR J0614-33
3.15 ms spin
unknown orbit~2 kpc (DM)
X-ray point
sources...
Very bright
Scintillation

Swift XRTConclusions●

3 out of 4 high-Galactic latitude sources searched so far
have bright radio MSPs!

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No γ-ray pulsations yet...(timing required)●

A new way to find such valuable systems:●●●

Basic physics tests (e.g. NS EoS)●

Gravitational wave detection (e.g. NANOGrav)

Still 18 more sources to search (4 high-lat)
Many more in Mallory Robert's 350MHz survey and othersearches at Parkes, Arecibo and Effelsberg●

γ-ray and radio luminosities of MSPs uncorrelated(?)●γ-ray and radio both likely have wide fan-beams