Multiwavelength identification of millisecond pulsar candidates in the Galactic bulge

Abstract

The existence of a population of millisecond pulsars in the Galactic bulge is supported, along with other evidence, by the Fermi GeV excess, an anomalous γ-ray emission detected almost 15 years ago in the direction of the Galactic center. However, radio surveys searching for pulsations have not yet revealed bulge millisecond pulsars. Identifying promising bulge millisecond pulsar candidates is key to motivating pointed radio pulsation searches. Candidates are often selected among steep-spectrum or polarized radio sources, but multiwavelength information can also be exploited: The aim of this work is to pinpoint strong candidates among the yet unidentified X-ray sources. We investigated the multiwavelength counterparts of sources detected by the Chandra X-ray observatory that have spectral properties expected for millisecond pulsars in the Galactic bulge. We considered that ultraviolet, optical, and strong infrared counterparts indicate that an X-ray source is not a bulge pulsar, while a radio or a faint infrared counterpart makes it a promising candidate. We identify a large population of more than a thousand X-ray sources without optical, ultraviolet, or strong infrared counterparts. Among them, five are seen for the first time in unpublished radio imaging data from the Very Large Array. We provide the list of promising candidates, for most of which follow-up pulsation searches are ongoing.

arXiv comment10 pages, 3 figures

References in corpus (47)

• The Gaia mission
• The ATNF Pulsar Catalogue
• The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• Search for an isotropic gravitational-wave background with the Parkes Pulsar Timing Array
• Searching for the nano-Hertz stochastic gravitational wave background with the Chinese Pulsar Timing Array Data Release I
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• CASA, the Common Astronomy Software Applications for Radio Astronomy
• The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals
• VISTA Variables in the Via Lactea (VVV): The public ESO near-IR variability survey of the Milky Way
• 2MASS Extended Source Catalog: Overview and Algorithms
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• The Second Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• The Chandra Source Catalog
• The UKIDSS Galactic Plane Survey
• Frame dragging and other precessional effects in black hole-pulsar binaries
• A Catalog of X-ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic Center
• The Third Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• A Quantitative Test of the No-Hair Theorem with Sgr A* using stars, pulsars, and the Event Horizon Telescope
• Probing the Spacetime Around Sgr A* with Radio Pulsars
• A new source detection algorithm using FDR
• The 1.28 GHz MeerKAT Galactic Center Mosaic
• The XMM-Newton serendipitous ultraviolet source survey catalogue
• Circular polarization in pulsar integrated profiles
• Classification of X-ray Sources in the XMM-Newton Serendipitous Source Catalog
• The Galactic Bulge Survey: outline and X-ray observations
• An all-sky survey of circular polarisation at 200 MHz
• The formation of the double neutron star pulsar J0737--3039
• Radio detection prospects for a bulge population of millisecond pulsars as suggested by Fermi LAT observations of the inner Galaxy
• A Catalog of Diffuse X-ray-Emitting Features within 20 pc of Sgr A*: Twenty Pulsar Wind Nebulae?
• An Ultra-deep Chandra Catalog of X-ray Point Sources in the Galactic Center Star Cluster
• The GCE in a New Light: Disentangling the $\gamma$-ray Sky with Bayesian Graph Convolutional Neural Networks
• X-ray Census of Millisecond Pulsars in the Galactic field
• Radial Distribution of X-ray Point Sources near the Galactic Center
• A neural simulation-based inference approach for characterizing the Galactic Center $\gamma$-ray excess
• Gaia pulsars and where to find them
• Dissecting the inner Galaxy with $\gamma$-ray pixel count statistics
• Probabilistic classification of X-ray sources applied to Swift-XRT and XMM-Newton catalogs
• The X-ray binary population in the Galactic Center revealed through multi-decade observations
• Dim but not entirely dark: Extracting the Galactic Center Excess' source-count distribution with neural nets
• Gravitational-Wave and X-ray Probes of the Neutron Star Equation of State
• Searching for pulsars associated with polarised point sources using LOFAR: Initial discoveries from the TULIPP project
• A population of compact radio variables and transients in the radio bright zone at the Galactic center observed with the Jansky Very Large Array
• Serendipitous Discovery of PSR J1431-6328 as a Highly-Polarized Point Source with the Australian SKA Pathfinder
• Spectral characterization of the non-thermal X-ray emission of gamma-ray pulsars
• The Galactic bulge millisecond pulsars shining in X rays: A gamma-ray perspective
• Massive Star Formation in the Galactic Center

Cited by in corpus (1)

• Einstein@Home Searches for Gamma-ray Pulsars in the Inner Galaxy