60 citations · 229 across the 22 of their papers we have counts for
23 papers
Magnetar Fireballs and Short Bursts: Curved Spacetime Lensing, QED Effects, Spectra, Polarization, and Impulse Responses
Zorawar Wadiasingh, Hoa Dinh Thi, Constantinos Kalapotharakos +12
Magnetar short bursts (SBs) are hard X-ray transients of durations s peaking at keV, and are prime targets for new high-energy missions and polarimeters. The…
In-orbit Demonstration of X-ray Pulsar Navigation with NinjaSat
Naoyuki Ota, Takuya Takahashi, Toru Tamagawa +26
This study demonstrated the pulsar navigation capability of the CubeSat X-ray observatory NinjaSat, which is equipped with two Gas Multiplier Counters (GMCs). The GMCs are sensitiv…
NICER Magnetar Burst Catalog
Che-Yen Chu, Chin-Ping Hu, Teruaki Enoto +13
In this paper, we present a comprehensive catalog of short bursts from magnetars based on eight years of NICER observations. A total of 1130 bursts were identified from 14 sources,…
Unveiling the Nature of Superorbital Modulation of SMC X-1 using NinjaSat
Chin-Ping Hu, Naoyuki Ota, Takuya Takahashi +13
We report a long-term, high-cadence timing and spectral observation of the X-ray pulsar SMC X-1 using NinjaSat, a 6U CubeSat in low-Earth orbit, covering nearly a full superorbital…
Return of the Clocked Burster: Exceptionally Short Recurrence Time in GS 1826-238
Tomoshi Takeda, Toru Tamagawa, Teruaki Enoto +15
We report the discovery of an exceptionally short burst recurrence time in the well-known clocked burster GS 1826238, observed with the CubeSat X-ray observatory NinjaSat. In 20…
Vacuum birefringence and the polarized X-ray emission from a radio magnetar
Rachael E. Stewart, Hoa Dinh Thi, George Younes +13
Magnetars are isolated neutron stars with exceptionally strong surface fields exceeding G. Their bright X-ray emission probes physical regimes in which quantum electrodyn…
Thermonuclear superburst of MAXI J1752457 observed with NinjaSat and MAXI
Amira Aoyama, Teruaki Enoto, Takuya Takahashi +17
An uncatalogued bright X-ray transient was detected with MAXI on November 9, 2024, named MAXI J1752457. The NinjaSat X-ray observatory promptly observed the source from November…
Rapid Spectral Evolution of SGR 1935+2154 During its 2022 Outburst
Chin-Ping Hu, Zorawar Wadiasingh, Wynn C. G. Ho +9
During the 2022 outburst of SGR 1935+2154, a Fast-Radio-Burst-like event (FRB 20221014A) and X-ray activities occurred between two spin-up glitches, suggesting these glitches may c…
Timing and Spectral Evolution of the Magnetar 1E 1841-045 in Outburst
G. Younes, S. K. Lander, M. G. Baring +19
We present the timing and spectral analyses of the NICER, NuSTAR, and IXPE observations of the magnetar 1E 1841-045 covering 82 days following its August 2024 bursting activity as…
NinjaSat: Astronomical X-ray CubeSat Observatory
Toru Tamagawa, Teruaki Enoto, Takao Kitaguchi +22
NinjaSat is an X-ray CubeSat designed for agile, long-term continuous observations of bright X-ray sources, with the size of 6U ( mm) and a mass of 8 kg.…
X-ray polarization of the magnetar 1E 1841-045
Rachael Stewart, George A. Younes, Alice K. Harding +15
We report on IXPE and NuSTAR observations beginning forty days after the 2024 outburst onset of magnetar 1E 1841-045, marking the first IXPE observation of a magnetar in an enhance…
NinjaSat monitoring of Type-I X-ray bursts from the clocked burster SRGA J144459.2604207
Tomoshi Takeda, Toru Tamagawa, Teruaki Enoto +25
The CubeSat X-ray observatory NinjaSat was launched on 2023 November 11 and has provided opportunities for agile and flexible monitoring of bright X-ray sources. On 2024 February 2…
Monitoring Observations of SMC X-1's Excursions (MOOSE) III: X-ray Spectroscopy of a Warped, Precessing Accretion Disc
Rawan Karam, Kristen C. Dage, Bailey E. Tetarenko +11
The MOOSE (Monitoring Observations of SMC X-1 Excursions) program uses the Neutron Star Interior Composition Explorer Mission (NICER) to monitor the high mass X-ray binary SMC X-1…
Rapid spin changes around a magnetar fast radio burst
Chin-Ping Hu, Takuto Narita, Teruaki Enoto +12
Magnetars are neutron stars with extremely high magnetic fields that exhibit various X-ray phenomena such as sporadic sub-second bursts, long-term persistent flux enhancements, and…
Similarity to earthquakes again: periodic radio pulses of the magnetar SGR 1935+2154 are accompanied by aftershocks like fast radio bursts
Yuya Tsuzuki, Tomonori Totani, Chin-Ping Hu +1
It was recently discovered that the time correlations of repeating fast radio bursts (FRBs) are similar to earthquake aftershocks. Motivated by the association between FRBs and mag…
A NICER View on the 2020 Magnetar-Like Outburst of PSR J1846-0258
Chin-Ping Hu, Lucien Kuiper, Alice K. Harding +6
We report on our monitoring of the strong-field magnetar-like pulsar PSR J1846-0258 with the Neutron Star Interior Composition Explorer (NICER) and the timing and spectral evolutio…
The 2022 high-energy outburst and radio disappearing act of the magnetar 1E 1547.0-5408
Marcus E. Lower, George Younes, Paul Scholz +19
We report the radio and high-energy properties of a new outburst from the radio-loud magnetar 1E 1547.05408. Following the detection of a short burst from the source with Swift-…
Investigation of a likely orbital periodicity of Nova Hercules 2021 in X-rays and gamma-rays
Lupin Chun-Che Lin, Jhih-Ling Fan, Chin-Ping Hu +2
We report a detection of a 0.153 days period in the classical nova V1674 Her using the NICER observations taken within a month since the outburst (i.e., about MJD 59405). The X-ray…
A Comprehensive Analysis of the Gravitational Wave Events with the Hilbert-Huang Transform: From Compact Binary Coalescence to Supernova
Chin-Ping Hu, Lupin Chun-Che Lin, Kuo-Chuan Pan +4
We analyze the gravitational wave signals with a model-independent time-frequency analysis, which is improved from the Hilbert-Huang transform (HHT) and optimized for characterizin…
BURSTT: Bustling Universe Radio Survey Telescope in Taiwan
Hsiu-Hsien Lin, Kai-yang Lin, Chao-Te Li +44
Fast Radio Bursts (FRBs) are bright millisecond-duration radio transients that appear about 1,000 times per day, all-sky, for a fluence threshold 5 Jy ms at 600 MHz. The FRB radio-…
Long term radio and X-ray evolution of the magnetar Swift J1818.0-1607
K. M. Rajwade, B. W. Stappers, A. G. Lyne +10
We report on the the long term monitoring campaign of the seemingly youngest magnetar Swift~J1818.0-1607 at radio and X-ray wavelengths over a span of one year. We obtained a coher…
X-ray burst and persistent emission properties of the magnetar SGR 1830-0645 in outburst
G. Younes, C. -P. Hu, K. Bansal +18
We report on NICER X-ray monitoring of the magnetar SGR 1830-0645 covering 223 days following its October 2020 outburst, as well as Chandra and radio observations. We present the m…
An optical and X-ray study of the contact binary, BH Cassiopeiae
Junhui Liu, Ali Esamdin, Yu Zhang +10
We present the revised and high quality CCD time series observations in 2017 and 2018 of the W UMa-type contact binary BH~Cas. The combination of our new determinations of minimum…