On the Deepest Search for Galactic Center Pulsars and an Examination of an Intriguing Millisecond Pulsar Candidate

Abstract

We report results of one of the most sensitive pulsar surveys to date targeting the innermost region of the Galactic Center (GC) using the Robert C. Byrd Green Bank Telescope (GBT) at X-band (8--12GHz) using data from the Breakthrough Listen initiative. In total, we collected 9.5 hr of data covering the wider $\sim 8^{\prime }$ diameter of the GC bulge, and 11 hr on the inner $1.4^{\prime }$ region between 2021 May and 2023 December. We conducted a comprehensive Fourier-domain periodicity search targeting both canonical pulsars (CPs) and millisecond pulsars (MSPs), using constant and linearly changing acceleration searches to improve sensitivity to compact binaries. Assuming weak scattering, our searches reached luminosity limits of $L_{\min }\approx 0.14\mathrm{mJy}\mathrm{kp}{\mathrm{c}}^2$ for CPs and $L_{\min }\approx 0.26\mathrm{mJy}\mathrm{kp}{\mathrm{c}}^2$ for MSPs -- sensitive enough to detect the most luminous pulsars expected in the GC. Among 5,282 signal candidates, we identify an interesting 8.19 ms MSP candidate (DM of 2775 pc cm${}^{-3}$), persistent in time and frequency across a 1-hr scan at a flux density of $S_{\min }\approx 0.007\mathrm{mJy}$. We introduce a novel randomization test for evaluating candidate significance against noise fluctuations, including signal persistence via Kolmogorov-Smirnov tests and flux-vs-DM behavior. We are unable to make a definitive claim about the candidate due to a mixed degree of confidence from these tests and, more broadly, its non-detection in subsequent observations. This deepens the ongoing missing pulsar problem in the GC, reinforcing the idea that strong scattering and/or extreme orbital dynamics may obscure pulsar signals in this region.

arXiv comment27 pages, 13 figures, published in ApJ

References in corpus (74)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• The ATNF Pulsar Catalogue
• Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar
• The Temperature of the Cosmic Microwave Background
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• PSRCHIVE and PSRFITS An Open Approach to Radio Pulsar Data Storage and Analysis
• A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty
• Stellar Orbits Around the Galactic Center Black Hole
• A Radio Pulsar/X-ray Binary Link
• DSPSR: Digital Signal Processing Software for Pulsar Astronomy
• A periodically active pulsar giving insight into magnetospheric physics
• A strong magnetic field around the supermassive black hole at the centre of the Galaxy
• Fourier Techniques for Very Long Astrophysical Time Series Analysis
• The Fermi Galactic Center GeV Excess and Implications for Dark Matter
• The characteristics of millisecond pulsar emission: I. Spectra, pulse shapes and the beaming fraction
• Searches for Fast Radio Transients
• Frame dragging and other precessional effects in black hole-pulsar binaries
• On the birthrates of Galactic neutron stars
• Prospects for Probing the Spacetime of Sgr A* with Pulsars
• An Extended Star Formation History for the Galactic Center from Hubble Space Telescope/NICMOS Observations
• An Overabundance of Transient X-ray Binaries within 1 pc of the Galactic Center
• 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
• Accelerating incoherent dedispersion
• The 1.28 GHz MeerKAT Galactic Center Mosaic
• Sgr A* and General Relativity
• Early formation and recent starburst activity in the nuclear disc of the Milky Way
• Hyperstrong Radio-Wave Scattering in the Galactic Center. II. A Likelihood Analysis of Free Electrons in the Galactic Center
• Arecibo Pulsar Survey Using ALFA. IV. Mock Spectrometer Data Analysis, Survey Sensitivity, and the Discovery of 41 Pulsars
• Multiwavelength Constraints on Pulsar Populations in the Galactic Center
• Discovery of Three Pulsars from a Galactic Center Pulsar Population
• G359.95-0.04: Pulsar Candidate Near Sgr A*
• A Fourier Domain "Jerk" Search for Binary Pulsars
• Discovery of 28 pulsars using new techniques for sorting pulsar candidates
• Pulse Broadening Measurements from the Galactic Center Pulsar J1745--2900
• Finding Radio Pulsars in and Beyond the Galactic Center
• A High-Frequency Search for Pulsars Within the Central Parsec of SgrA*
• Discovery of two pulsars towards the Galactic Centre
• A survey of nulling pulsars using the Giant Meterwave Radio Telescope
• The Peculiar Pulsar Population of the Central Parsec
• A comparison of Galactic electron density models using PyGEDM
• The Breakthrough Listen Search for Intelligent Life: A Wideband Data Recorder System for the Robert C. Byrd Green Bank Telescope
• Pulsar-black hole binaries: prospects for new gravity tests with future radio telescopes
• The Breakthrough Listen Search for Intelligent Life: Public Data, Formats, Reduction and Archiving
• The Breakthrough Listen Search For Intelligent Life Near the Galactic Center I
• Pulsar-Black Hole Binaries in the Galactic Center
• Einstein@Home Discovery of 24 Pulsars in the Parkes Multi-beam Pulsar Survey
• Detecting pulsars in the Galactic centre
• On Detecting Millisecond Pulsars at the Galactic Center
• Pulse Morphology of the Galactic Center Magnetar PSR J1745-2900
• Single-pulse radio observations of the Galactic Center magnetar PSR J1745-2900
• PSR J2322$-$2650 -- A low-luminosity millisecond pulsar with a planetary-mass companion
• Formation of Tidal Captures and Gravitational Wave Inspirals in Binary-Single Interactions
• A coherent acceleration search of the Parkes multi-beam pulsar survey - techniques and the discovery and timing of 16 pulsars
• On the detectability of eccentric binary pulsars
• Locating the intense interstellar scattering towards the inner Galaxy
• The X-ray binary population in the Galactic Center revealed through multi-decade observations
• The High Time Resolution Universe Pulsar Survey - VII: discovery of five millisecond pulsars and the different luminosity properties of binary and isolated recycled pulsars
• Probing the formation history of the nuclear star cluster at the Galactic Centre with millisecond pulsars
• Searching for broadband pulsed beacons from 1883 stars using neural networks
• An 86-GHz search for Pulsars in the Galactic Center with the Atacama Large Millimeter/submillimeter Array
• A population of compact radio variables and transients in the radio bright zone at the Galactic center observed with the Jansky Very Large Array
• Searching for pulsars in the Galactic Centre at 3 and 2 mm
• Strong field effects on pulsar arrival times: general orientations
• Strong field effects on pulsar arrival times: circular orbits and equatorial beams
• Multi-epoch searches for relativistic binary pulsars and fast transients in the Galactic Centre
• Rotation measure variations in Galactic Centre pulsars
• Fermi LAT observations of Sagittarius A*: Imaging Analysis
• Testing space-time geometries and theories of gravity at the Galactic Center with pulsar's time delay
• Green Bank Telescope Discovery of the Redback Binary Millisecond Pulsar PSR J0212+5321
• $4-8\mathrm{GHz}$ Spectro-temporal Emission from the Galactic Center Magnetar $\mathrm{PSR}J1745-2900$
• Performance of a novel fast transients detection system
• Millisecond Pulsar Kicks Cause Difficulties in Explaining the Galactic Center Gamma-Ray Excess
• Observability of pulsar beam bending by the Sgr~A* black hole