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Tatehiro Mihara (RIKEN MAXI team)10/12/2024, 10:3020m
MAXI has been working for 15 years and contributing to a part of the time-domain astronomy by the quick alerts of transients. The main instrument GSC of MAXI has been stable after some damage occurred in the first year. The other instrument SSC has damaged due to the radiation damage. The main system of the MAXI suffered abrupt shut down twice in 2022 June. Since then SSC was stopped to reduce...
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Hitoshi Negoro (Nihon University)10/12/2024, 10:5020m
MAXI discovered 35 newly discovered X-ray novae or short transients, including 14 or more black hole candidates and the first Be/whit-dwarf nova MAXI J0158-744. The nature of some of them are still unknown. MAXI also detected a number of X-ray novae and X-ray or gamma bursts. I briefly summarize those transients sources MAXI discoverd/detected in 15 years.
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Jamie Kennea (Penn State)10/12/2024, 11:1030m
The Neil Gehrels Swift Observatory, which turns 20 years old in November 2024, is an epochal mission for TDAMM science thanks to it's rapid response capabilities, allowing for fast turn around observation of transients both discovered by Swift itself, and other observatories. It's combination of sensitive X-ray and UV/Optical telescopes allows for broadband follow-up of events discovered by...
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Sean Pike (UC, San Diego)10/12/2024, 11:4020m
MAXI provides all-sky monitoring in the X-ray band, identifying multiple new sources each year, but a fraction of these transient sources falls too close to the Sun for most X-ray observatories to safely perform rapid follow-up observations. NuSTAR, however, is able to observe sources with much smaller angular separation from the Sun than other observatories, making it a uniquely capable tool...
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Weimin Yuan (National Astronomical Observatories, Chinese Academy of Sciences)10/12/2024, 13:3030m
The Einstein Probe (EP) is a space X-ray observatory designed to detect mainly high-energy transient and variable sources in the universe. It aims at detecting such sources at unprecedented sensitivity and spatial resolution in the soft X-ray band and performing quick onboard follow-up observations in X-rays. The Einstein Probe is a project led by the Chinese Academy of Sciences in...
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Dongyue Li (National Astronomical Observatories, CAS)10/12/2024, 14:0520m
Eintein Probe (EP) is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability, and was lauched on January 9, 2024. It carried out a series of performance verification and calibration observation after launch and had begun scientific observations since late July. By now, EP has detected more than 30 fast X-ray transients, and long-term transients of different...
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Makoto Tashiro (Saitama univ)10/12/2024, 14:2530m
The X-Ray Imaging and Spectroscopy Mission (XRISM) project was initiated in 2018. Following the development of onboard components, the proto-flight was conducted from 2021 to 2023 at JAXA Tsukuba Space Center. The spacecraft was launched from JAXA Tanegashima Space Center on September 7, 2023, and onboard components, including the observation instruments, were activated during the four months...
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Tomokage Yoneyama (Chuo University)10/12/2024, 15:2030m
X-ray Imaging and Spectroscopy Mission (XRISM) has two X-ray instruments. Resolve, an X-ray microcalorimeter, has an extreme energy resolution of 5 eV at 6 keV. Xtend, an X-ray CCD array, has a large field of view (FoV) of 38 arcmin square, which gives us opportunities to observe many serendipitous sources. We developed the XRISM/Xtend Transient Search (XTS), a project to quick search and fast...
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Yohko Tsuboi (Chuo University)10/12/2024, 15:5030m
Since MAXI's launch in 2009, we have continuously surveyed stellar flares. The flare sample now exceeds 200 and has been found to originate from about 30 active stars, including RS CVn systems, Algol systems, dMe stars, dKe stars, YSOs, and undefined-type stars. The observed parameters of these MAXI flares are: luminosity of 10^31-10^34 erg s-1 in the 2-20 keV band, emission of 10^54-10^57...
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Miki Kurihara (UTokyo, ISAS)10/12/2024, 16:2015m
We detected a giant X-ray flare from the RS-CVn type binary star UX Ari using MAXI on 2020 August 17 and started a series of NICER observations 89 minutes later. For a week, the entire duration of the flare was covered with 32 snapshot observations including the rising phase. The X-ray luminosity reached 2$\times$10$^{33}$~erg~s$^{-1}$ and the entire energy release was $\sim 10^{38}$~erg in...
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Roger Romani (Stanford University)10/12/2024, 17:0030m
The Imaging X-ray Polarimeter Explorer (IXPE) has opened up a new window on the X-ray sky, with observations of nearly 100 sources. In this talk I summarize IXPE's technical advances, the challenges of polarization measurements, our successes to date and the prospects for future discovery. IXPE has obtained polarization images of a number of X-ray nebulae, including pulsar wind nebulae and...
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Wataru Iwakiri (Chiba University)10/12/2024, 17:3020m
MAXI provides us with a powerful tool for detecting soft X-ray transients, such as outbursts of LMXBs or HMXBs, long-duration X-ray bursts, and stellar flares. To investigate more detailed physical processes of these X-ray transients, it is important to obtain the precision timing and spectroscopy data by rapid follow-up observations with high-sensitivity X-ray detectors. The Neutron Star...
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Anna Ho (Cornell University)10/12/2024, 17:5030m
For the last half-century, relativistic outflows accompanying the final collapse of massive stars have predominantly been detected via high-energy emission, as long-duration gamma-ray bursts (GRBs). Yet, it has long been hypothesized that GRBs are the tip of the iceberg of relativistic stellar explosions, because the conditions required to produce and detect a GRB are contrived. I will present...
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Erik Kuulkers (ESA)11/12/2024, 09:0030m
This presentation will review the main, unique, contributions of the INTErnational Gamma-Ray Astrophysics Laboratory, INTEGRAL, to time domain astronomy.
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Biswajit Paul (Raman Research Institute)11/12/2024, 09:3020m
Orbital phase-resolved spectroscopy of High Mass X-ray Binaries (HMXBs) allow detailed probe of the X-ray reprocessing environment and line of sight absorption of the X-rays by the stellar wind through different lines of sights in the binary. Same study, when carried out at different intensity levels of a given binary system allows probes of the changes in the reprocessing/absorption agents...
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Atsuo Okazaki (Hokkai-Gakuen University)11/12/2024, 09:5015m
Be X-ray binaries (BeXRBs) consist of a Be star (a massive star with a circumstellar disk) and a neutron star. They constitute a prominent subclass within the category of high-mass X-ray binaries, characterized by their transient nature. These binaries intermittently exhibit X-ray outbursts, whereas the rest of the time they remain quiescent. On the transition between these two X-ray activity...
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Kazuo Makishima (The University of Tokyo and RIKEN)11/12/2024, 10:0515m
Advanced timing studies of archival data from ASCA, Suzaku, NuSTAR, and XMM-Newton are opening several novel aspects of magnetars. (1a) Representative 7 magnetars were found to be axially deformed to 10^{-4}, and performs free precession. (1b) The deformation is due to internal magnetic pressure, with the internal (toroidal) magnetic fields reaching 10^{16} G (Makishima+24a, 24b). (2a) The...
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Lian Tao (Institute of High Energy Physics, Chinese Academy of Sciences)11/12/2024, 10:4030m
The Insight-HXMT space mission is China's first X-ray astronomical satellite, which has been in orbit for over 7 years. Its main scientific objectives include searching and monitoring transients in the disk of the Milky Way, observing X-ray binaries to study the motion and radiation mechanisms in strong gravitational or magnetic fields, and monitoring and studying gamma-ray bursts and...
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Mutsumi Sugizaki (Kanazawa University)11/12/2024, 11:1020m
We report on the results of MAXI monitoring of X-ray binary pulsars (XBPs), which are mostly high-mass X-ray binaries hosted by Be stars or OB supergiants. So far, about a hundred of XBPs have been known in our Galaxy. More than a half of them appear as X-ray transients whose activity are limited within their short (< several months) outburst periods. The MAXI all-sky survey for 15 years...
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Chin-Ping Hu (National Changhua University of Education)11/12/2024, 11:3015m
SMC X-1 is a high-mass X-ray binary exhibiting superorbital modulation with an unstable period. Monitoring carried out by RXTE/ASM, Swift/BAT, and MAXI revealed excursion events in 1996–1998, 2005–2007, and 2014–2016, during which the superorbital period drifted from ~60 days to ~40 days. These events occurred at intervals of about 3,200 days. However, recent observations suggest that a new...
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Kumiko Nobukawa (Kindai University)11/12/2024, 11:4515m
MAXI J1421-613 is an X-ray burster discovered by MAXI on 9 January 2014 and is considered to be a low-mass X-ray binary. We report the discovery of an annular emission around MAXI J1421-613 in Suzaku and Swift follow-up observations. The Swift follow-up observation which was conducted by the photon counting mode on 18 January 2014 found an annular emission at ?2.5'--4.5' whereas the Suzaku...
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Megumi Shidatsu (Ehime University)11/12/2024, 13:4030m
Since the start of the operation in 2009, MAXI has detected many outbursts from newly discovered and known Galactic black hole and neutron star X-ray binaries. They were promptly reported to the astronomical community over the world, which stimulated follow-up observations at various wavelengths. MAXI itself also provided unique long-term X-ray data covering their entire outburst periods,...
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Melania Del Santo (INAF/IASF Palermo)11/12/2024, 14:1015m
The X-ray transient MAXI J1810-222 was discovered by MAXI in 2018 and has been active ever since. A long, combined radio and X-ray monitoring campaign was performed with ATCA and Swift, respectively. It gas been identified as a black hole candidate, even though the highly unusual outburst behaviour and the absence of information regarding the distance or the donor leaves the nature of the...
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Ruchika Dhaka (Indian Institute of Technology Kanpur)11/12/2024, 14:2515m
In this study, we undertake a spectral-timing analysis of the black hole X-ray binary source GRS 1915+105 using simultaneous observations carried out by AstroSat and NICER. The source showed two flux levels (high and low), whose energy spectra can be described by the thermal comptonization of disk photons. The spectral parameters obtained by the joint fitting of SXT/LAXPC and NICER/LAXPC were...
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Stéphane Corbel (Univ. Paris Cité / CEA Saclay / Observatoire de Paris)11/12/2024, 14:4030m
Since the launch of MAXI 15 years ago, several considerable achievements have been reached in the field of Galactic accreting binary systems, especially in light of the extreme variability of their relativistic jets. These jets have now been recognized as vital component for energy transfer and angular momentum in black holes. Although the phenomenology is now rather well established, their...
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David Russell (New York University Abu Dhabi (NYUAD))11/12/2024, 15:3030m
Despite decades of research, predicting outbursts of X-ray transients, and witnessing their beginning stages, remains very challenging. The cause of these X-ray brightenings is thought to be the sudden increase of accretion of matter onto a black hole or neutron star, initiated by the ionization of hydrogen in the accretion disc. I present recent observational advances in our understanding of...
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Kevin Alabarta (New York University Abu Dhabi (NYUAD))11/12/2024, 16:0020m
Usually, X-ray binary (XRB) outbursts are first detected by X-ray all-sky monitors like MAXI. Only after this are observations with more sensitive multi-wavelength telescopes triggered. This causes a gap in the coverage of the rise of the outbursts, limiting our knowledge of their early stages. Therefore, the best approach to better understand the accretion process in XRBs is to combine X-ray...
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Shuaikang Yang (Wuhan University)11/12/2024, 16:2015m
Multi-wavelength observations are essential to understand the coupling between the accretion flow and the jet in black hole X-ray binary (BHXRB). We investigate the X-ray and radio emissions in MAXI J1348-630 during its 2019 outburst. For the first time, we find that the radio emission lags behind the X-ray Comptonization emission by about 3 days during the rising phase covering the rising...
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Alexandra Tetarenko (University of Lethbridge)11/12/2024, 16:5530m
The most powerful cosmic engines in our universe are fueled by compact objects such as black holes and neutron stars. These cosmic engines accrete large amounts of material and eject matter in the form of jets traveling at near the speed of light. Recent groundbreaking discoveries of gravitational waves from systems harbouring compact objects and the direct imaging of the black hole shadows...
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Bei You (Wuhan University)11/12/2024, 17:2520m
A black hole X-ray binary produces hard X-ray radiation from its corona and disk when the accreting matter heats up. During an outburst, the disk and corona co-evolve with each other. MAXI J1820 + 070 (ASASSN-18ey) is a low-mass BH X-ray binary, discovered in X-rays with MAXI on 11 March 2018. During the 2018 outburst, this source underwent the rising hard state, the soft state, and then the...
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Chris Done (university of durham)12/12/2024, 09:0020m
The transient X-ray outbursts of galactic binaries give some of the most spectacular lightcurves seen by MAXI and other monitoring instruments. I will review what these reveal about the accretion flow, and how it links to the transient radio jets. The luminous accretion flow also powers winds, now revealed in exquisite detail in XRISM, and I will speculate on how these relate to the accretion...
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Hajime Inoue (ISAS/JAXA)12/12/2024, 09:2015m
In a steady mass flow from a companion star to a compact object in an X-ray binary, the inflowing matter from the companion star is expected to carry a certain amount of specific angular momentum and to first form a geometrically thick ring tube along the Keplerian circular orbit, which is called the accretion ring. A study of the accretion ring by Inoue (2021, PASJ, 73, 795) showed that a...
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Ryoji Matsumoto (Chiba University)12/12/2024, 09:3520m
We present the results of three-dimensional global radiation magnetohydrodynamic simulations of state transitions in black hole candidates. During the hard-to-soft state transition, accretion flow near the black hole tends to be in optically thin hot state even when the accretion rate exceeds the upper limit for RIAF in the outer region. In such state, RIAF near the black hole co-exists with...
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Maxime Parra (Ehime University)12/12/2024, 09:5515m
Despite having one of the most detailed outburst coverage among BHLMXBs, the long term behavior of the wind in 4U 1630-47 remains poorly known. We thus performed an exhaustive study of archival X-ray observations of the source, combining Chandra, NICER, NuSTAR, Suzaku and XMM-Newton, for more than 200 epochs spanned over 9 separate outbursts and two decades, complemented by Swift-BAT and...
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Ryota Tomaru (Osaka University)12/12/2024, 10:1015m
Accretion disk winds in compact objects in low-mass X-ray binaries, suggested by the blue-shifted absorption lines in spectroscopic data, are important phenomena to address the understanding of the physics of AGN feedback. However, the driving mechanisms of the winds are unclear. To tackle this, we build a comprehensive model for X-ray spectra, where the detail line profiles are simulated by...
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Hirofumi Noda (Tohoku University)12/12/2024, 10:4520m
According to the unified model of active galactic nuclei (AGNs), a dusty torus is formed around a broad-line region, accretion disk, and corona near a supermassive black hole (SMBH), and these structures produce multi-wavelength radiation. Studying the structures in not only type-1 but also type-2 AGNs is important to understand e.g., the growth of a SMBH via mass accretion and the AGN...
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Chichuan Jin (National Astronomical Observatories, Chinese Academy of Sciences)12/12/2024, 11:0520m
The Einstein Probe (EP) is a newly launched space mission dedicated to the X-ray all-sky survey and characterization of all kinds of high-energy transients. During the first few months of in-orbit operation, EP has discovered dozens of new X-ray transients with intriguing properties. In this talk, I will present a few typical examples of TDE candidates discovered by EP since its launch,...
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Huaqing Cheng (National Astronomical Observatories, Chinese Academy of Sciences)12/12/2024, 11:2515m
The broad-band emission (optical/UV to X-ray) of luminous active galactic nuclei (AGNs) is believed to be powered by accretion onto central supermassive black holes, with the optical/UV emission generally explained as from the standard accretion disc, and the X-ray emission often explained as the inverse Compton scattering of the soft photons from the accretion disc in a hot corona above. This...
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Tomoshi Takeda (RIKEN/Tokyo university of Science)12/12/2024, 11:4015m
NinjaSat is the RIKEN's 6U-size X-ray CubeSat launched on 2023 November 11. The main instrument is Xe-based proportional counter covering the energy range of 2--50~keV. Just after we finished the satellite commissioning in 2024 February, the new X-ray transient SRGA J144459.2-604207 appeared. NinjaSat observed SRGA J1444 from 2024 from February 21 to March 18. Meanwhile, NinjaSat detected 12...
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Satoshi Sugita (AoyamaGakuin University)12/12/2024, 11:5515m
MAXI scans about 85% of the whole sky in its orbital period (92 min) by sweeping the sky with a slit-shaped field-of-view (FOV). It can cover a large localized area of a GW event detected by GW detectors and search for an emission from the area before the time of the GW trigger. From the start of LIGO’s operation, MAXI has searched for X-ray counterparts of GW events and reported on upper...
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Jean-Luc Atteia (IRAP - Toulouse)12/12/2024, 13:3030m
This talk will start with a presentation of the SVOM mission and the homonymous satellite, which was successfully launched on June 22nd 2024, with a special focus on the ECLAIRs hard X-ray imager. Then, the operations performed during the commissioning and early science phases will be described, along with the tuning of some crucial parameters. This will lead to the description of ECLAIRs...
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Hiroki Hiramatsu (Aoyama Gakuin University)12/12/2024, 14:0020m
The Monitor of All-sky X-ray Image (MAXI) has been observing the X-ray sky and has detected 164 GRBs since its launch in 2009. MAXI is suitable for detecting transient events such as GRB due to its unique scanning observation. Recently, Low luminosity GRBs (LL GRBs) have become a key in multi-messenger astronomy. However, only a few of these events have been observed by all detectors so far....
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Heyang Liu (National Astronomical Observatories, Chinese Academy of Sciences)12/12/2024, 14:2020m
Lobster Eye Imager for Astronomy (LEIA) is a pathfinder of the wide-field X-ray telescope of the Einstein Probe (EP) mission. The piggyback imager, launched in 2022 July, has a mostly unvignetted field of view of 18°. 6 × 18°.6. Its spatial resolution is in the range of 4–7 arcmin in FWHM and the focal spot effective area is 2–3 square centimeter, both showing only mild fluctuations across the...
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Hui Sun (National Astronomical Observatories, Chinese Academy of Sciences)12/12/2024, 14:4015m
The central engine that powers gamma-ray bursts (GRBs) is still not identified. Besides hyper- accreting black holes, rapidly spinning and highly magnetized neutron stars, known as millisec- ond magnetars, have been suggested to power both long and short GRBs. Indirect indications of a magnetar engine in these merger sources have been observed in the form of plateau fea- tures present in the...
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Qianqing Yin (Institute of High Energy Physics, CAS)12/12/2024, 14:5515m
The Chasing All Transients Constellation Hunters (CATCH) space mission, proposed in 2019, is an AI-controlled astronomical constellation dedicated to monitoring X-ray emissions from tran-sients across the entire sky. The mission aims to enhance our understanding of the extreme uni-verse through X-ray imaging, spectral, timing, and polarization measurements. Plans are also in place to introduce...
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Xuan Mao (National Astronomical Observatories, Chinese Academy of Sciences)poster
LEIA (Lobster Eye Imager for Astronomy) detected a new X-ray transient on November 7, 2022, identified as a superflare event occurring on a nearby RS CVn-type binary HD 251108. The flux increase was also detected in follow-up observations at X-ray, UV and optical wavelengths. The flare lasted for about forty days in soft X-ray observations, reaching a peak luminosity of ∼ 1.1 × 10^34 erg s^−1...
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Dipak Debnath (Insttute of Astronomy Space and Earth Science)poster
MAXI is one of the most successful astronomy mission satellites which discovered 14 Galactic X-ray binaries to date. We studied the accretion flow properties of 7 black hole candidates (BHCs; such as MAXI J1659-152, MAXI J1836-194, MAXI J1543-564, MAXI J1535-571, MAXI J1348-630, MAXI J1813-095, MAXI J1910-057) using one of the generalized physical accretion flow models, namely Two-component...
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Tianying Lian (National Astronomical Observatories, Chinese Academy of Science (NAOC))poster
The core of active galactic nuclei (AGN) may be surrounded by numerous clouds in diverse physical states. These clumpy clouds can randomly obscure the central X-ray source, leading to eclipse events. Recent studies indicated that such events are likely common in AGN. However, the complete eclipse events are rarely discovered, because they require extensive X-ray monitoring spanning years. In...
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Tomohiro Yanagi (Chuo University)poster
The X-ray Imaging Spectroscopy Mission (XRISM) was launched on September 7th 2023, and the onboard Xtend is now performing spectral imaging in the 0.4-13 keV band with a wide field of view of 38 arcminutes. “XRISM/Xtend Transient Search (XTS)” is a system to conduct a transient search by utilizing the wide field of view of Xtend once per a day. With the high sensitivity of about 10^-14 ergs^-1...
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Yuno Kudo (Nihon University)poster
MAXI has discovered 35 new X-ray transients since 2009. Sources in source-crowded regions such as the Galactic bulge regions, however, have not been investigated intensively because of relatively low spatial resolution (~ 1 deg) X-ray cameras. We are therefore trying to discover X-ray novae and other transient objects by creating light curves at regions around the Galactic bulge at equal...
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Yuki Niida (Ehime University)poster
We studied accretion torque induced change in the pulse period derivative of the X-ray binary pulsar A 0535+262 using the long-term light curve from the MAXI/GSC and the time variation of the pulse period from the Fermi/GBM. We found a clear anti-correlation between the bolometric luminosity and the period derivative. We applied the accretion torque model proposed by Ghosh and Lamb (1979) to...
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Xiaobo Li (Institute of High Energy Physics)poster
As China's first X-ray astronomy satellite, the Hard X-ray Modulation Telescope (HXMT) has been successfully operational in orbit for about 7 years. It is equipped with three payloads, covering band ranging from 1 to 250 keV. This poster aims to provide a comprehensive overview of HXMT's operational status, with a focus on its scientific proposals, data products, the performance of its three...
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Mikio Morii (Japan Aerospace Exploration Agency)poster
We, Science Satellite Operation and Data Archive Unit (C-SODA) in JAXA, have developed FTOOLS-based software (mxsim_psf and mxsim_bgd), which can make simulations of point spread function (PSF) and non X-ray background (NXB) of MAXI/GSC. These tools will be released from HEASARC, soon. By using these tools, we start to develop a tool to make MAXI/GSC light curves obtained by image-fits using...
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Yuta Kawakubo (Aoyama Gakuin University)poster
In the past two decades, multi-wavelength observations of astronomical objects and phenomena using electromagnetic waves have become commonplace. Furthermore, multi-messenger astronomy, which includes messengers beyond electromagnetic waves, such as gravitational waves and neutrinos, is emerging as the new standard. The Multi-Messenger Observation Database and Viewer compile and visualize...
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164. Discovery of the black hole X-ray nova MAXI J1631-479 and understanding its peculiar propertiesKohei Kobayashi (Nihon University (Current Affiliation: MAMEZOU CO., LTD))poster
MAXI J1631-479 was discovered on 2018 December 21 by MAXI, and exhibited a fast rise and exponential decay type of the outburst. After the low/hard state at the beginning of the outburst, the source underwent a variety of state transitions. The source, however, had been mostly in the high/soft state after about 100 days from the discovery until the X-ray flux decreased by about four orders of...
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Saien Xu (School of Physics and Technology, Wuhan University)poster
Black hole X-ray binaries (BHXRBs) undergo hard-soft-hard state during their outbursts. In the soft state, the energy spectrum is dominated by thermal emission from the accretion disk, which is thought to extend down to the innermost stable circular orbit. In contrast, during the hard state, the disk is truncated at a larger radius, and the spectrum is dominated by a comptonization component...
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Yu Miyazato (Chiba University)poster
In recent years, magnetic turbulence in the hot coronae of Seyfert galaxies has been proposed as a potential source for high-energy neutrino production. This model predicts that the signal strength of neutrinos originating from the coronae correlates with X-ray intensity, and experimentally constraining this correlation could provide a deeper understanding of high-energy neutrino and cosmic...
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Mariko Kimura (Kanazawa univ.)poster
MAXI J1820+070 is a low-mass X-ray binary harboring a black hole. It entered a very bright outburst in 2018. We performed shot analyses of X-ray and optical sub-second flares observed during the low/hard state of that outbursts. The advantage of shot analyses is that the average flare shape can be preserved. We found that the timescale of shots was about 0.2 s and that optical shots were less...
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Christopher Irwin (RESCEU, University of Tokyo)poster
The first detectable light of a supernova explosion is the shock breakout emission, which is produced as the supernova shock wave breaches the star's surface and which acts as a powerful diagnostic for the pre-explosion state of the progenitor system. I will discuss a novel way of categorizing the possible spectra observed immediately after breakout, and the recent advances in shock breakout...
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Mikio Morii (Japan Aerospace Exploration Agency)poster
We develop a new deconvolution method to recover the Crab Nebula image taken by the Hitomi HXT. To suppress the artifact due to the bright Crab pulsar located at the center of the Crab Nebula, we extend the Richardson-Lucy method. Here, we introduce two components corresponding to the nebula and pulsar with regularization for smoothness and flux, respectively, and we perform simultaneous...
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Taichi Nakamoto (Ehime University)poster
We report the results of X-ray spectral analysis of the Galactic black hole X-ray binary Swift J1727.8-1613 during its outburst. It showed one of the largest outbursts ever observed in black hole X-ray binaries and was monitored by many X-ray observatories. Using the NICER spectra obtained at various epochs in the outburst, we investigated the accretion disk structure and its evolution. We...
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Shino Sugawara (Rikkyo univ. and RIKEN)poster
A strong solar flare of X6.3 class occurred on February 22, 2024. X-rays from the solar flare are reflected by the moon, MAXI captured the fluorescent X-rays. MAXI detected emission lines of three elements, Si, Ca, and Fe. Those were consistent with the main elements of the moon surface. We considered a model of the reflected X-rays by the moon and compared the intensities of the calculated...
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Dr Akira Dohi (RIKEN)poster
Recently, (Type-I) X-ray bursts have been observed in a neutron star SRGA J144459.2-604207 by various X-ray satellites, firstly INTEGRAL and NinjaSat (Atel: 16485, 16495). To summarize their observations shortly, in the early phase, they show very regular behavior, i.e., Clocked bursters, but in the latter phase, they become irregular. From such a Clocked burster with various properties, we...
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Motoki Nakajima (Nihon University)poster
We present the analysis results of normal outbursts (NOBs) from Be/X-ray binary pulsars (BeXBPs) observed by the MAXI/GSC. Since August 2009, over 200 X-ray outbursts were detected over a period of 15 years. Using the data obtained by the MAXI/GSC, we investigated the NOB profiles of BeXBPs from onset to end. The ascent phases of the NOBs are approximated by a linear function, from which we...
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Yuki Taki (Rikkyo University and RIKEN)poster
We analyzed 186 cluster of galaxies with MAXI and obtained luminosity, temperature, and abundance. Significant abundance was obtained from 32 clusters, whose average was 0.29 +- 0.06. It is consistent with the previous works. The temperature was obtained from 179 clusters, from which the relation between the luminosity and temperature was obtained as L is proportional to T^4.01. This value was...
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Motoko Serino (Aoyama Gakuin Univ.)poster
Short X-ray transients are observed by various X-ray missions. Origins of these transients are both galactic (X-ray bursts, stellar flares, soft gamma-ray repeaters, etc.) and extra-galactic (Gamma-ray bursts, tidal disruption events, AGNs, etc.). Among them MAXI observed short soft transients which were not observed by other instruments including X-ray follow-up observations. We summarize the...
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Masahiro Morikawa (Riken)poster
A fair number of MAXI X-ray sources show pink noise (power index -0.8 to -1.2 ) in their power spectral density toward the lowest frequency, the inverse of 15 years. This pink noise is quite robust and reappears after thresholding, inverse-thresholding, and even after removing the energy information, leaving only the timing data. We explore the origin of this robust pink noise in MAXI sources....
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Tristan Bouchet (CEA Saclay)poster
Microquasars are known to produce strong hard X-ray emission during their outbursts, which is thought to be either inverse Compton emission, synchrotron emission or a mix of both. Although challenging to measure properly, polarization is a critical tool to distinguish between them. For this task, the IBIS telescope onboard the INTEGRAL satellite can be used to probe the polarization of bright...
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Masafumi Niwano (Tokyo Tech)poster
The mechanism of X-ray outbursts in Be X-ray binaries remains a mystery, and understanding their circumstellar disks is crucial for a solution of the mass-transfer problem. In particular, it is important to identify the Be star activities (e.g., pulsations) that cause mass ejection and, hence, disk formation. Therefore, we investigated the relationship between optical flux oscillations and the...
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Ryuji Kondo (Kanazawa univ.)poster
Wide-field soft X-ray surveys are important for future gamma-ray burst observations. The HiZ-GUNDAM satellite will use lobster-eye optics and pnCCDs to observe soft X-ray transients such as gamma-ray bursts. In this study, the radiation tolerance of a small pnCCD with a pixel size of 75 µm and a depletion thickness of 450 µm was evaluated. In this test, radiation damage due to orbital total...
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Congying Bao (NAOC)poster
The time-domain X-ray space mission Einstein Probe (EP) was launched on January 9, 2024. Since then, EP had been undergoing extensive in-orbit tests and calibration until July 2024. EP is aimed for the detection of cosmic high-energy transients in soft X-rays and quick X-ray follow-up characterization. For this, there are two instruments onboard: a wide-field X-ray telescope (WXT) for...
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Ken Ebisawa (ISAS/JAXA)poster
At DARTS (JAXA) and HEASARC (NASA), we maintain the permanent MAXI data archive, which keeps calibrated GSC event files on a daily basis. Any kind of data analysis is available using MAXI FTOOLS (mxproduct etc) and CALDB provided by HEASARC. Still, it is reported that there are minor discrepancies between the results obtained by DARTS/HEASRC archive and those by the public light curves and...
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Marina Yoshimoto (Osaka University)poster
XRISM/Xtend has a large Field of View (FOV; 38′×38′) and can detect serendipitous transient X-ray phenomena in the FOV. XRISM/Xtend detected a supergiant fast X-ray transient from AX J1910.7+0917 during observation of PV target W49B. The AX J1910.7+0917 is the slowest X-ray pulsar with a rotation period of ~ 10 hours. In the spectral analysis, the time average spectrum is reproduced with an...
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Qinyu Wu (National Astronomical Observatories, Chinese Academy of Sciences)poster
Extragalactic Fast X-ray Transients (eFXTs) are defined as short flares in X ray with cosmological origins. But the nature of eFXT is still uncertain due to the lack of timely follow up observations. The possible physical mechanisms include the shock breakout of a supernova, the fireball phase of a nova, the magnetar powered X-ray emission after the mergers of binary neutron stars, off-axis...
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Xiang Ma (Institute of High Energy Physics, CAS)poster
We report the X-ray timing results of the black hole candidate MAXI J1820+070 during its 2018 outburst using the Hard X-ray Modulation Telescope (Insight-HXMT) and Neutron Star Interior Composition Explorer Mission (NICER) observations. Low-frequency quasi-periodic oscillations (LFQPOs) are detected in the low/hard state and the hard intermediate state, which lasted for ∼90 days. Thanks to the...
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Masanori Akimoto (Yamaguchi university)poster
Swift/BAT first reported the detection of the X-ray transient Swift J1727.8-1613 on 2023 August 24 (Page+2023). Optical observations revealed that Swift J1727.8-1613 has a black hole candidate larger than 3.2 Msun and a K4V donor (Mata Sanchez+2023). Black hole X-ray binaries have an accretion state responsible for the ejection of large-scale or compact jets. The formation process of these...
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Xinpeng Xu (NAOC)poster
For X-ray spectra with low counts, traditional statistics such as 𝜒2 statistic and Poisson (C) statistic cannot well enough evaluate the goodness-of-fit during model fitting, because the binning process is usually arbitrary and would result in the loss of channel information. The maximum-likelihood estimation method is an ideal alternative method that does not require any binning procedures....
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Giancarlo Cusumano (INAF - IASF Palermo)poster
Pulse profiles of X-ray pulsars are invaluable tools for understanding emission mechanisms, system geometry, and radiation transfer under extreme conditions. By extracting energy-dependent pulse profiles Ferrigno (2023) showed how the changes in the pulse shape at energies corresponding to the cyclotron resonance scattering features, provide a quantitative way of determining the feature main...
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Chulsoo Kang (Ehime University)poster
The black hole X-ray binary 4U 1630-472 shows outbursts repeatedly with an interval of 600 days. We studied the 2012 outburst, which was one of the biggest outbursts of the source. We found unusual X-ray flux drops by ~50% with a duration of ~1 day at its brightest phase, which is much shorter than the timescale of accretion but longer than the dynamical timescale in the inner region of the...
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Yuta Kondo (Aoyamagakuin University)poster
In the O4a period of gravitational wave observation, only two LIGO observatories were available, and thus, a 90% credible region was typically several percent to several tens of percent of the whole sky. Therefore, we need instruments with a wide field of views. Monitor of All-sky X-ray Image (MAXI) is an X-ray detector aboard the International Space Station (ISS). MAXI is sensitive to X-rays...
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Hao Huang (Institute of Modern Physics, Chinese Academy of Sciences)poster
The cooling effect of $^{63}$Fe$-$$^{63}$Mn Urca pair on the neutron star surface has been evaluated based on the state-of-the-art shell model calculations which reproduced the experimental spectroscopy results in the neutron-rich N $\sim$ 40 region. It is concluded that $^{63}$Fe$-$$^{63}$Mn could be among the strongest Urca pairs in the neutron star crust. This pair has been identified as...
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Jingwei Hu (National Astronomical Observatories, Chinese Academy of Sciences)poster
The Einstein Probe (EP) is an interdisciplinary mission of time-domain and X-ray astronomy. It was launched into orbit from the Xichang satellite launch centre on January 9, 2024. From 2024 July the commissioning and calibration phase was successfully completed and the nominal operations phase has started. The Wide-field X-ray Telescope (WXT), one of the two main payloads on board EP, is to...
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Kazutaka Yamaoka (Nagoya Univ.)poster
We compiled the X-ray and soft gamma-ray observations of the Galactic black hole binary XTE J1859+226 in the 1999–2000 outburst from RXTE, ASCA, BeppoSAX and CGRO. Throughout systematic spectral analysis using a two-component model consisting of a multi-temperature accretion disk plus a fraction of its flux convolved with a phenomenological cutoff powerlaw component resembling Comptonizaion,...
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Yukiko Ishihara (Chuo University)poster
XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a Chandra X-ray source CXOGNC J104457.51-595429.5, which was identified with a Gaia source, DR2 5350302509372303744 or Cl Collinder 228 113 (ATel #16652). From the SED and the distance of ∼1.3 kpc, we found that Cl Collinder 228 113 has the spectrum type of K7 giant. The X-ray spectrum of this source has a strong Fe-K line at the...
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Alok Gupta (ARIES, Nainital)poster
It is a well established fact that AGNs show large amplitude flux and occasional quasi periodic oscillations (QPOs) in their X-ray light curves. For the last 1.5 decades, my group has extensively worked on searching for X-ray variations in two subclasses of active galactic nuclei (AGNs) namely narrow line Seyfert 1 (NLSy1) and blazars. We have used various X-ray missions e.g. MAXI, XMM-Newton,...
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Nagisa Nagashima (Chuo univ.)poster
HR 1099 (V711 Tau) is one of the most active RS Canum Venaticorum binaries with an orbital period of 2.8377 days and has been extensively studied at various wavelengths. It is a non-eclipsing, double-lined spectroscopic binary with a K0 - K1 subgiant primary and a G5 dwarf secondary in a nearly circular orbit (Fekel 1983). We observed this object from March 6 to 10 (UT) with XRISM as one of...
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Anje Yoshimoto (Nara Women's University)poster
XRISM PV observation of the Galactic Center detected an interesting transient source named CXOU J174610.8-290019 within the Xtend FoV. The spectrum shows an intensity ratio of Fe-XXVI and Fe-XXV corresponding to kT>20 keV in comparison with a moderate bremsstrahlung continuum of kT~5 keV. We present the results of spectral and timing analyses.
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