Constraining the X-ray - Infrared spectral index of second-timescale flares from SGR1935+2154 with Palomar Gattini-IR

Abstract

The Galactic magnetar SGR1935+2154 has been reported to produce the first known example of a bright millisecond duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs), bolstering the association of FRBs to active magnetars. The detection of a coincident bright X-ray burst has revealed the first observed multi-wavelength counterpart of a FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared wavelengths using the Palomar Gattini-IR observing system in J-band, made possible by a recently implemented detector read-out mode that allowed for short exposure times of 0.84 s with 99.9% observing efficiency. With a total observing time of 12 hours (47728 images) on source, we place median $3\sigma$ limits on the second-timescale emission of $<20$ mJy (13.1 AB mag). We present non-detection limits from epochs of four simultaneous X-ray bursts detected by the Insight-{\it HXMT} and {\it NuSTAR} telescopes during our observing campaign. The limits translate to an extinction corrected fluence limit of $<125$ Jy ms for an estimated extinction of $A_J=2.0$ mag. These limits provide the most stringent constraints to date on the fluence of flares at frequencies of $\sim 10^{14}$ Hz, and constrain the ratio of the near-infrared (NIR) fluence to that of coincident X-ray bursts to $R_{\mathrm{NIR}}<2.5\times 10^{-2}$. Our observations were sensitive enough to easily detect a near-infrared counterpart of FRB 200428 if the NIR emission falls on the same power law as that observed across its radio to X-ray spectrum. The non-detection of NIR emission around the coincident X-ray bursts constrains the fluence index of the brightest burst to be steeper than $0.35$.

arXiv comment10 pages, 4 figures, submitted to ApJL. Comments welcome

References in corpus (31)

• A 3D Dust Map Based on Gaia, Pan-STARRS 1 and 2MASS
• Drizzle: A Method for the Linear Reconstruction of Undersampled Images
• The Relation Between Optical Extinction and Hydrogen Column Density in the Galaxy
• Fast Radio Bursts
• Fast Radio Bursts: An Extragalactic Enigma
• A model for fast extragalactic radio bursts
• Fast radio bursts as synchrotron maser emission from decelerating relativistic blast waves
• INTEGRAL discovery of a burst with associated radio emission from the magnetar SGR 1935+2154
• Fast radio burst source properties and curvature radiation model
• Supergiant Pulses from Extragalactic Neutron Stars
• Proper image subtraction - optimal transient detection, photometry and hypothesis testing
• Blast Waves from Magnetar Flares and Fast Radio Bursts
• The discovery, monitoring and environment of SGR J1935+2154
• Implications of a "Fast Radio Burst" from a Galactic Magnetar
• On the radiation mechanism of repeating fast radio bursts
• Local Circumnuclear Magnetar Solution to Extragalactic Fast Radio Bursts
• A search for optical bursts from the repeating fast radio burst FRB 121102
• X-ray and radio observations of the magnetar SGR J1935+2154 during its 2014, 2015, and 2016 outbursts
• A Sino-German 6cm polarization survey of the Galactic plane VII. Small supernova remnants
• Palomar Gattini-IR: Survey overview, data processing system, on-sky performance and first results
• Burst properties of the most recurring transient magnetar SGR J1935+2154
• Correlated Infrared and X-ray Flux Changes Following the 2002 June Outburst of the Anomalous X-ray Pulsar 1E 2259+586
• On the Distance of SGR 1935+2154 Associated with FRB 200428 and Hosted in SNR G57.2+0.8
• Discovery and Monitoring of the likely IR Counterpart of SGR 1806-20 during the 2004 gamma-ray burst-active state
• Infrared and X-ray variability of the transient Anomalous X-ray Pulsar XTE J1810-197
• The first observation of an intermediate flare from SGR 1935+2154
• Optical and infrared flares from a transient Galactic soft gamma-ray repeater
• The multiwavelength counterparts of fast radio bursts
• Zwicky Transient Facility constraints on the optical emission from the nearby repeating FRB 180916.J0158+65
• Radio Pulsation Search and Imaging Study of SGR J1935+2154
• Identification of the infrared counterpart of SGR 1935+2154 with the Hubble Space Telescope

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