Identifying the 3FHL Catalog. VI. Swift Observations of 3FHL Unassociated Objects with Source Classification via Machine Learning

Abstract

The Third Catalog of Hard Fermi Large Area Telescope Sources (3FHL) reports the detection of 1556 objects at E > 10 GeV. However, 177 sources remain unassociated and 23 are associated with a ROSAT X-ray detection of unknown origin. Pointed X-ray observations were conducted on 30 of these unassociated and unknown sources with Swift-XRT. A bright X-ray source counterpart was detected in 21 out of 30 fields. In five of these 21 fields, we detected more than one X-ray counterpart, totaling 26 X-ray sources analyzed. Multiwavelength data was compiled for each X-ray source detected. We find that 21 out of the 26 X-ray sources detected display the multiwavelength properties of blazars, while one X-ray source displays the characteristics of a Galactic source. Using trained decision tree, random forest, and support vector machine models, we predict all 21 blazar counterpart candidates to be BL Lacertae objects (BL Lacs). This is in agreement with BL Lacs being the most populous source class in the 3FHL.

arXiv comment15 pages, 11 figures, interactive plot link see, https://authortools.aas.org/AAS40568/figNint.html

References in corpus (55)

• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• On the Absorption of X-rays in the Interstellar Medium
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The Swift X-ray Telescope
• The SIMBAD astronomical database
• The Swift Ultra-Violet/Optical Telescope
• HI4PI: A full-sky HI survey based on EBHIS and GASS
• The VizieR database of Astronomical Catalogues
• The Fermi Gamma-Ray Burst Monitor
• Fermi Large Area Telescope Fourth Source Catalog
• The Spectral Energy Distribution of Fermi bright blazars
• Toward the Standard Population Synthesis Model of the X-Ray Background: Evolution of X-Ray Luminosity and Absorption Functions of Active Galactic Nuclei Including Compton-Thick Populations
• Incremental Fermi Large Area Telescope Fourth Source Catalog
• The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• Development of the Model of Galactic Interstellar Emission for Standard Point-Source Analysis of Fermi Large Area Telescope Data
• Roma-BZCAT: A multifrequency catalogue of Blazars
• The XMM-Newton serendipitous survey IX. The fourth XMM-Newton serendipitous source catalogue
• 3FHL: The Third Catalog of Hard Fermi-LAT Sources
• Modeling the Emission Processes in Blazars
• 2FHL: The Second Catalog of Hard Fermi-LAT Sources
• The Cosmic Evolution of Fermi BL Lacertae Objects
• Hard X-ray properties of blazars
• The First Fermi-LAT Catalog of Sources Above 10 GeV
• The Origin of the Extragalactic Gamma-Ray Background and Implications for Dark-Matter Annihilation
• 2SXPS: An improved and expanded Swift X-ray telescope point source catalog
• A $\gamma$-ray determination of the Universe's star-formation history
• Swift X-ray Telescope Monitoring of Fermi-LAT Gamma Ray Sources of Interest
• The WISE gamma-ray strip parametrization: the nature of the gamma-ray Active Galactic Nuclei of Uncertain type
• Classification and Ranking of Fermi LAT Gamma-ray Sources from the 3FGL Catalog using Machine Learning Techniques
• Multiwavelength Observations of the Powerful Gamma-ray Quasar PKS 1510-089: Clues on the Jet Composition
• ESO-VLT optical spectroscopy of BL Lac objects: II. New redshifts, featureless objects and classification assessments
• A new measurement of the Hubble constant and matter content of the Universe using extragalactic background light $\gamma$-ray attenuation
• Two new catalogs of blazar candidates in the WISE infrared sky
• Optical Spectroscopic Observations of Gamma-ray Blazar Candidates. V. TNG, KPNO, and OAN Observations of Blazar Candidates of Uncertain Type in the Northern Hemisphere
• Optical spectroscopic survey of a sample of Unidentified Fermi objects
• Research and characterisation of blazar candidates among the Fermi/LAT 3FGL catalogue using multivariate classifications
• 3FGLzoo. Classifying 3FGL Unassociated Fermi-LAT Gamma-ray Sources by Artificial Neural Networks
• Optical spectroscopic survey of a sample of Unidentified Fermi objects: II
• Broadband Observations of High Redshift Blazars
• The Highest-Energy Photons Seen by the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory
• A new method to unveil blazars among multi-wavelength counterparts of Unassociated Fermi gamma-ray Sources
• Identifying the 3FHL catalog: CTIO results
• Identifying the 3FHL catalog: I. Results of the KOSMOS optical spectroscopy campaign
• Multiwavelength Spectral Analysis and Neural Network Classification of Counterparts to 4FGL Unassociated Sources
• Source-count Distribution of Gamma-Ray Blazars
• A serendipitous discovery of GeV gamma-ray emission from supernova 2004dj in a survey of nearby star-forming galaxies with Fermi-LAT
• High-redshift blazars through nustar eyes
• X-ray Spectra and Multiwavelength Machine Learning Classification for Likely Counterparts to Fermi 3FGL Unassociated Sources
• Identifying the 3FHL catalog: I. Archival Swift Observations and Source Classification
• Identifying the 3FHL catalog: V. Results of the CTIO-COSMOS optical spectroscopy campaign 2019
• Identifying the 3FHL Catalog. IV. Swift Observations of Unassociated Fermi-LAT 3FHL Sources

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• A Multiwavelength Machine-learning Approach to Classifying X-ray Sources in the Fields of Unidentified 4FGL-DR4 sources
• A New Mid-Infrared and X-ray Machine Learning Algorithm to Discover Compton-thick AGN
• Identifying the 3FHL catalog: VI. Results of the 2019 Gemini optical spectroscopy campaign
• Future Detections of the Warm-Hot Intergalactic Medium using Bright Power Law Sources with NewAthena
• Exploring the nature of Galactic unassociated sources detected by the Fermi-LAT