Motoko Serino

Gas Slit Camera (GSC) onboard MAXI on ISS

The Gas Slit Camera (GSC) is an X-ray instrument on the MAXI (Monitor of All-sky X-ray Image) mission on the International Space Station. It is designed to scan the entire sky every 92-minute orbital period in the 2‐30 keV band and to achieve the highest sensitivity among the X-ray all-sky monitors ever flown so far. The GSC employs large-area position-sensitive proportional counters with the total detector area of 5350 cm 2 . The on-board data processor has functions to format telemetry data as well as to control the high voltage of the proportional counters to protect them from the particle irradiation. The paper describes the instruments, on-board data processing, telemetry data formats, and performance specifications expected from the ground calibration tests.

In-Orbit Performance of MAXI Gas Slit Camera (GSC) on ISS

We report the in-orbit performance of the Gas Slit Camera (GSC) on the MAXI (Monitor of All-sky X-ray Image) mission carried on the International Space Station (ISS). Its commissioning operation started on August 8, 2009, confirmed the basic performances of the effective area in the energy band of 2--30 keV, the spatial resolution of the slit-and-slat collimator and detector with 1.5 degree FWHM, the source visibility of 40-150 seconds for each scan cycle, and the sky coverage of 85% per 92-minute orbital period and 95% per day. The gas gains and read-out amplifier gains have been stable within 1%. The background rate is consistent with the past X-ray experiments operated at the similar low-earth orbit if its relation with the geomagnetic cutoff rigidity is extrapolated to the high latitude. We also present the status of the in-orbit operation and the calibration of the effective area and the energy response matrix using Crab-nebula data.

The First MAXI/GSC Catalog in the High Galactic-Latitude Sky

AbstractWe present the first unbiased source catalog of the Monitor of All-sky X-ray Image (MAXI) mission athigh Galactic latitudes (|b|>10 ◦ ), produced from the first 7-month data (2009 September 1 to 2010 March31) of the Gas Slit Camera in the 4–10 keV band. We develop an analysis procedure to detect faint sourcesfrom the MAXI data, utilizing a maximum likelihood image fitting method, where the image response,background, and detailed observational conditions are taken into account. The catalog consists of 143X-ray sources above 7 sigma significance level with a limiting sensitivity of ∼ 1.5×10 −11 ergs cm −2 s −1 (1.2 mCrab) in the 4–10 keV band. Among them, we identify 38 Galactic/LMC/SMC objects, 48 galaxyclusters, 39 Seyfert galaxies, 12 blazars, and 1 galaxy. Other 4 sources are confused with multiple objects,and one remains unidentified. The log N - log S relation of extragalactic objects is in a good agreementwith the HEAO-1 A-2 result, although the list of the brightest AGNs in the entire sky has significantlychanged since that in 30 years ago.Key words:catalogs — surveys — galaxies: active — X-rays: galaxies1. INTRODUCTIONAll-sky X-ray surveys are powerful tools to investigatethe whole populations of active and hot phenomena inthe universe at the brightest flux end. The strong X-ray emitters include Galactic objects such as active stars,SNRs, pulsars, CVs, low mass and high mass X-ray bi-naries (with a neutron star or a black hole as the pri-mary), and extragalactic objects, mainly active galacticnuclei (AGNs; Seyfert galaxies and blazars) and clustersof galaxies. The source catalog consisting of a statisticallywell-defined sample detected from an unbiased survey isa primary product on which many subsequent studies arebased. For extragalactic populations, in particular, theseresults define the “local” sample in the present universe,the end point of their cosmological evolution. Thus, toestablish the statistical properties of bright X-ray sourcesusing the best quality data over the entire sky has alwaysbeen a key issue in high energy astrophysics.Past all-sky X-ray surveys indeed brought valuable in-formation on the X-ray source populations. In the softX-ray band, the ROSAT mission conducted an all-sky sur-vey in the 0.1–2.4 keV band, producing the ROSAT All-Sky Survey (RASS) Bright Source Catalog (BSC; Voges

Revisit of Local X-Ray Luminosity Function of Active Galactic Nuclei with the MAXI Extragalactic Survey

We construct a new X-ray (2--10 keV) luminosity function of Compton-thin active galactic nuclei (AGNs) in the local universe, using the first MAXI/GSC source catalog surveyed in the 4--10 keV band. The sample consists of 37 non-blazar AGNs at

A spectral study of the black hole candidate XTE J1752-223 in the high/soft state with MAXI, Suzaku, and Swift

z=0.002-0.2

Large X-ray flares on stars detected with MAXI/GSC: A universal correlation between the duration of a flare and its X-ray luminosity

, whose identification is highly (

Slow and Fast Transitions in the Rising Phase of Outbursts from NS-LMXB Transients, Aquila X-1 and 4U 1608-52

>97%

High-z gamma-ray bursts for unraveling the dark ages mission HiZ-GUNDAM

) complete. We confirm the trend that the fraction of absorbed AGNs with

X-Ray Reflection and an Exceptionally Long Thermonuclear Helium Burst from IGR J17062-6143

N_{\rm H} > 10^{22}

Outburst of LSV+44 17 Observed by MAXI and RXTE, and Discovery of a Dip Structure in the Pulse Profile

cm