An image-based search for pulsars among Fermi unassociated LAT sources

Abstract

We describe an image-based method that uses two radio criteria, compactness and spectral index, to identify promising pulsar candidates among Fermi Large Area Telescope (LAT) unassociated sources. These criteria are applied to those radio sources from the Giant Metrewave Radio Telescope all-sky survey at 150 MHz (TGSS ADR1) found within the error ellipses of unassociated sources from the 3FGL catalog and a preliminary source list based on 7 years of LAT data. After follow-up interferometric observations to identify extended or variable sources, a list of 16 compact, steep-spectrum candidates is generated. An ongoing search for pulsations in these candidates, in gamma rays and radio, has found six millisecond pulsars and one normal pulsar. A comparison of this method with existing selection criteria based on gamma-ray spectral and variability properties suggests that the pulsar discovery space using Fermi may be larger than previously thought. Radio imaging is a hitherto underutilized source selection method that can be used, as with other multi-wavelength techniques, in the search for Fermi pulsars.

MNRAS, in press (13 pages, 12 figures, 4 tables)

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Cited by in corpus (15)

• The Third Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• Optical spectroscopy and demographics of redback millisecond pulsar binaries
• Neutron star mass estimates from gamma-ray eclipses in spider millisecond pulsar binaries
• Measuring the mass of the black widow PSR J1555-2908
• A black widow population dissection through HiPERCAM multi-band light curve modelling
• Searching for pulsars associated with polarised point sources using LOFAR: Initial discoveries from the TULIPP project
• Discovery of PSR J0523-7125 as a Circularly Polarized Variable Radio Source in the Large Magellanic Cloud
• Discovery, Timing, and Multiwavelength Observations of the Black Widow Millisecond Pulsar PSR J1555-2908
• Classifications of Fermi-LAT unassociated sources in multiple machine learning methods
• The MAVERIC survey: A catalogue of radio sources in southern globular clusters from the Australia Telescope Compact Array
• A GMRT 150 MHz Search for Variables and Transients in Stripe 82
• Is the black-widow pulsar PSR J1555-2908 in a hierarchical triple system?
• Radio counterparts of gamma-ray sources in the Cygnus region
• Identifying pulsar candidates in interferometric radio images using scintillation
• Searching for Gamma-Ray Millisecond Pulsars: Selection of Candidates Revisited