J/ApJ/910/160 Fermi LAT sources observed with the GMRT (Bhattacharyya+, 2021)
Discovery and timing of three millisecond pulsars in radio and gamma-rays with
the Giant Metrewave Radio Telescope and Fermi Large Area Telescope.
Bhattacharyya B., Roy J., Johnson T.J., Ray P.S., Freire P.C.C., Gupta Y.,
Bhattacharya D., Kaninghat A., Stappers B.W., Ferrara E.C., Sengupta S.,
Rathour R.S., Kerr M., Smith D.A., Parkinson P.M.S., Ransom S.M.,
Michelson P.F.
<Astrophys. J., 910, 160 (2021)>
=2021ApJ...910..160B 2021ApJ...910..160B
ADC_Keywords: Pulsars; Gamma rays; Radio sources
Keywords: High energy astrophysics ; High time resolution astrophysics ;
Millisecond pulsars ; Radio astronomy ; Gamma-ray astronomy ;
Binary pulsars
Abstract:
We performed deep observations to search for radio pulsations in the
directions of 375 unassociated Fermi Large Area Telescope γ-ray
sources using the Giant Metrewave Radio Telescope (GMRT) at 322 and
607MHz. In this paper we report the discovery of three millisecond
pulsars (MSPs), PSR J0248+4230, PSR J1207-5050, and PSR J1536-4948. We
conducted follow-up timing observations for ∼5yr with the GMRT and
derived phase-coherent timing models for these MSPs. PSR J0248+4230
and J1207-5050 are isolated MSPs having periodicities of 2.60ms and
4.84ms. PSR J1536-4948 is a 3.07ms pulsar in a binary system with an
orbital period of ∼62 days about a companion of a minimum mass of
0.32M☉. We also present multifrequency pulse profiles of these
MSPs from the GMRT observations. PSR J1536-4948 is an MSP with an
extremely wide pulse profile having multiple components. Using the
radio timing ephemeris we subsequently detected γ-ray pulsations
from these three MSPs, confirming them as the sources powering the
γ-ray emission. For PSR J1536-4948 we performed combined
radio-γ-ray timing using ∼11.6yr of γ-ray pulse times of
arrival (TOAs) along with the radio TOAs. PSR J1536-4948 also shows
evidence for pulsed γ-ray emission out to above 25GeV,
confirming earlier associations of this MSP with a ≥10GeV point
source. The multiwavelength pulse profiles of all three MSPs offer
challenges to models of radio and γ-ray emission in pulsar
magnetospheres.
Description:
As part of a broader effort coordinated by the Fermi PSC, we selected
sources from early versions of the Fermi-LAT catalogs (Abdo+ 2010,
J/ApJS/188/405 and Nolan+ 2012, J/ApJS/199/31), analyses of sources
that were not associated with likely γ-ray-emitting counterparts
and were visible from the Giant Metrewave Radio Telescope (GMRT).
The search observations were performed between 2010 November and 2013
September with the GMRT Software Backend (GSB), producing simultaneous
incoherent and coherent beam filter-bank outputs of 512x0.0651MHz
sampled every 61.44us. Details of the observational configuration are
described in Bhattacharyya+ (2013ApJ...773L..12B 2013ApJ...773L..12B).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 65 339 Summary of the GMRT observations
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See also:
B/psr : ATNF Pulsar Catalogue (Manchester+, 2005)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJ/753/83 : Associations to 1FGL sources (Ackermann+, 2012)
J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)
J/ApJS/208/17 : 2nd Fermi LAT cat. of gamma-ray pulsars (2PC) (Abdo+, 2013)
J/ApJS/209/34 : The first Fermi-LAT >10GeV catalog (1FHL) (Ackermann+, 2013)
J/ApJS/232/18 : The third Fermi-LAT >10GeV catalog (3FHL) (Ajello+, 2017)
J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- ID Source designation
14- 15 I2 h RAh Hour of right ascension (J2000)
17- 18 I2 min RAm Minute of right ascension (J2000)
20- 24 F5.2 s RAs Second of right ascension (J2000)
26 A1 --- DE- Sign of declination (J2000)
27- 28 I2 deg DEd Degree of declination (J2000)
30- 31 I2 arcmin DEm Arcminute of declination (J2000)
33- 36 F4.1 arcsec DEs Arcsecond of declination (J2000)
38- 53 F16.10 d MJD [55521.59/56552.14] Observing epoch (MJD)
55- 57 I3 MHz Freq [322/607] Observed frequency
59- 61 I3 min Dur [3/150] Duration
63- 65 F3.1 mJy Smin [0.2/4.9] 10σ detection limit (1)
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Note (1): 10σ detection threshold calculated using the radiometer
equation (Lorimer & Kramer 2004hpa..book.....L 2004hpa..book.....L) with the GMRT
Exposure Time Calculator (ETC).
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History:
From electronic version (PDF) of the journal
(End) Emmanuelle Perret [CDS] 20-Sep-2022