A Multi-wavelength search for Black Widows and Redbacks counterparts of candidate $\gamma$-ray millisecond pulsars

Abstract

The wealth of detections of millisecond pulsars (MSPs) in $\gamma$-rays by {\em Fermi} has spurred searches for these objects among the several unidentified $\gamma$-ray sources. Interesting targets are a sub-class of binary MSPs, dubbed "Black Widows" (BWs) and "Redbacks" (RBs), which are in orbit with low-mass non-degenerate companions fully or partially ablated by irradiation from the MSP wind. These systems can be easily missed in radio pulsar surveys owing to the eclipse of the radio signal by the intra-binary plasma from the ablated companion star photosphere, making them better targets for multi-wavelength observations. We used optical and X-ray data from public databases to carry out a systematic investigation of all the unidentified $\gamma$-ray sources from the Fermi Large Area Telescope (LAT) Third Source Catalog (3FGL), which have been pre-selected as likely MSP candidates according to a machine-learning technique analysis. We tested our procedure by recovering known binary BW/RB identifications and searched for new ones, finding possible candidates. At the same time, we investigated previously proposed BW/RB identifications and we ruled out one of them based upon the updated $\gamma$-ray source coordinates.

22 pages, 14 figures, 21 pages - This manuscript is based on the MSc Thesis work of C. Braglia, defended on April 2020 at the University of Milan, accepted for publication in MNRAS

References in corpus (19)

• The Zwicky Transient Facility: System Overview, Performance, and First Results
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• A Radio Pulsar/X-ray Binary Link
• Introduction to astroML: Machine Learning for Astrophysics
• Optical spectroscopy and demographics of redback millisecond pulsar binaries
• Binary Millisecond Pulsar Discovery via Gamma-Ray Pulsations
• X-ray states of redback millisecond pulsars
• Identification of the High-Energy Gamma-Ray Source 3FGL J1544.6-1125 as a Transitional Millisecond Pulsar Binary in an Accreting State
• The Einstein@Home Gamma-ray Pulsar Survey. I. Search Methods, Sensitivity and Discovery of New Young Gamma-ray Pulsars
• The NuSTAR Serendipitous Survey: Hunting for The Most Extreme Obscured AGN at >10 keV
• Radio Detection of the Fermi LAT Blind Search Millisecond Pulsar J1311-3430
• 1FGL J0523.5-2529: A New Probable Gamma-ray Pulsar Binary
• 2FGL J1653.6-0159: A New Low in Evaporating Pulsar Binary Periods
• Search for transitions between states in redbacks and black widows using seven years of Fermi-LAT observations
• An investigation on the factors affecting machine learning classifications in $\gamma$-ray astronomy
• A Likely Redback Millisecond Pulsar Counterpart of 3FGL J0838.8-2829
• Orbital Dynamics of Candidate Transitional Millisecond Pulsar 3FGL J1544.6-1125: An unusually face-on system
• Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS
• The Hubble Catalog of Variables (HCV)

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• Deeper analysis of Fermi-LAT unassociated 4FGL J2112.5-3043 for possible identification