Discovery of Three Candidate Magnetar-powered Fast X-ray Transients from Chandra Archival Data

Abstract

It was proposed that a remnant stable magnetar could be formed in a binary neutron-star merger, leading to a fast X-ray transient (FXT) that can last for thousands of seconds. Recently, Xue et al. suggested that CDF-S XT2 was exactly such a kind of source. If confirmed, such emission can be used to search for electromagnetic counterparts to gravitational wave events from binary neutron-star mergers that have short gamma-ray bursts and the corresponding afterglows seen off-axis and thus too weak to be detected. Here we report the discovery of three new FXTs, XRT 170901, XRT 030511, and XRT 110919, from preliminary search over Chandra archival data. Similar to CDF-S XT2, these new FXTs had a very fast rise (less than a few ten seconds) and a plateau of X-ray flux $\sim$$1.0\times 10^{-12}$ erg s${}^{-1}$ cm${}^{-2}$ lasting for 1-2 ks, followed by a steep decay. Their optical/IR counterparts, if present, are very weak, arguing against a stellar flare origin for these FXTs. For XRT 170901, we identified a faint host galaxy with the source at the outskirts, very similar to CDF-S XT2. Therefore, our newly discovered FXTs are also strong candidates for magnetar-powered X-ray transients resulting from binary neutron star mergers.

arXiv comment13 pages, 9 figures, submitted version after addressing the referee's comments

References in corpus (51)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• GW190425: Observation of a Compact Binary Coalescence with Total Mass $\sim 3.4M_{\odot }$
• An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A
• Short-Duration Gamma-Ray Bursts
• Evidence for a Canonical GRB Afterglow Light Curve in the Swift/XRT Data
• A kilonova as the electromagnetic counterpart to a gravitational-wave source
• The 70 Month Swift-BAT All-Sky Hard X-Ray Survey
• Swift and NuSTAR observations of GW170817: detection of a blue kilonova
• What is the Most Promising Electromagnetic Counterpart of a Neutron Star Binary Merger?
• An extremely luminous X-ray outburst at the birth of a supernova
• Signatures of magnetar central engines in short GRB lightcurves
• The Dark Energy Survey Data Release 1
• Stellar SEDs from 0.3-2.5 Microns: Tracing the Stellar Locus and Searching for Color Outliers in SDSS and 2MASS
• X-Ray Flares from Postmerger Millisecond Pulsars
• Bayesian Estimation of Hardness Ratios: Modeling and Computations
• The Afterglow, Energetics and Host Galaxy of the Short-Hard Gamma-Ray Burst 051221a
• Early X-ray and optical afterglow of gravitational wave bursts from mergers of binary neutron stars
• Off-axis emission of short gamma-ray bursts and the detectability of electromagnetic counterparts of gravitational wave detected binary mergers
• Short GRB 130603B: Discovery of a jet break in the optical and radio afterglows, and a mysterious late-time X-ray excess
• The Swift Burst Analyser I: BAT and XRT spectral and flux evolution of Gamma Ray Bursts
• Can X-ray emission powered by a spinning-down magnetar explain some GRB light curve features?
• The prompt-afterglow connection in Gamma-Ray Bursts: a comprehensive statistical analysis of Swift X-ray light-curves
• Jet Breaks in Short Gamma-Ray Bursts. II: The Collimated Afterglow of GRB 051221A
• Chandra Multiwavelength Project X-ray Point Source Catalog
• X-ray Flashes from Off-axis Gamma-Ray Bursts
• Constraining properties of GRB magnetar central engines using the observed plateau luminosity and duration correlation
• The WFC3 Infrared Spectroscopic Parallel (WISP) Survey
• A complete sample of bright Swift short Gamma-Ray Bursts
• A magnetar-powered X-ray transient as the aftermath of a binary neutron-star merger
• Effects of Fall-Back Accretion on Proto-Magnetar Outflows in Gamma-Ray Bursts and Superluminous Supernovae
• Bright broad-band afterglows of gravitational wave bursts from mergers of binary neutron stars
• On the magnetar origin of the GRBs presenting X-ray afterglow plateaus
• Discovery of a new kind of explosive X-ray transient near M86
• Classification of X-ray Sources in the XMM-Newton Serendipitous Source Catalog
• A New, Faint Population of X-ray Transients
• Physics of radiation mediated shocks and its applications to GRBs, supernovae, and neutron star mergers
• Ultraluminous X-ray bursts in two ultracompact companions to nearby elliptical galaxies
• Two fast X-ray transients in archival Chandra data
• Blasts from the Past: Supernova Shock Breakouts among X-Ray Transients in the XMM-Newton Archive
• Unveiling the population of orphan Gamma Ray Bursts
• Swift follow-up of gravitational wave triggers: results from the first aLIGO run and optimisation for the future
• A unified binary neutron star merger magnetar model for the Chandra X-ray transients CDF-S XT1 and XT2
• Optical and X-ray Rest-frame Light Curves of the BAT6 sample
• A Supernova Candidate at z=0.092 in XMM-Newton Archival Data
• On the properties of a newborn magnetar powering the X-ray transient CDF-S XT2
• Discovery of the Candidate Off-nuclear Ultrasoft Hyper-luminous X-ray Source 3XMM J141711.1+522541
• CDF-S XT1 and XT2: White Dwarf Tidal Disruption Events by Intermediate-Mass Black Holes?
• Constraining the Braking Index and Energy Partition of Magnetar spindown with {\em Swift}/XRT data
• The electromagnetic and gravitational-wave radiations of X-ray transient CDF-S XT2

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• Science objectives of the Einstein Probe mission
• Extragalactic fast X-ray transient candidates discovered by Chandra (2000-2014)
• Extragalactic FXT Candidates Discovered by Chandra (2014-2022)
• On the diversity of magnetar-driven kilonovae
• A fast X-ray transient from a weak relativistic jet associated with a type Ic-BL supernova
• The Fast X-ray Transient XRT 210423 and its Host Galaxy
• EP241021a: a months-duration X-ray transient with luminous optical and radio emission
• New JWST redshifts for the host galaxies of CDF-S XT1 and XT2: understanding their nature
• Representation Learning for Time-Domain High-Energy Astrophysics: Discovery of Extragalactic Fast X-ray Transient XRT 200515
• Redshifts of candidate host galaxies of four fast X-ray transients using VLT/MUSE
• Comparing the Space Densities of Millisecond-Spin Magnetars and Fast X-Ray Transients
• The STATiX pipeline for the detection of X-ray transients in three dimensions
• Unveiling the nature of the Einstein Probe transient EP 241021a
• Characterising EP241107a: Multiwavelength Observations of an Einstein Probe-detected Fast X-ray Transient
• Search for the Optical Counterpart of Einstein Probe Discovered Fast X-ray Transients from Lulin Observatory
• Extracting latent representations from X-ray spectra. Classification, regression, and accretion signatures of Chandra sources
• Identifying Host Galaxies of Binary Black Hole Mergers with Next-Generation Gravitational Wave Detector Networks