We have returned to the regular data process since March 25. The data between March 11-24 are to be filled succeedingly. In addition, we started a frequent update service in every 4 hours, first for 4U 1608-52 (ATel #3237) and Swift J164449.3+573451 (ATel #3244).
The ISS-opration building in JAXA Tsukuba space center was damaged by the earthquake on March 11, 2011. The building contains the computers which receive MAXI telemetry data from NASA and store them. The computers have stopped since then. MAXI data also stopped and we can not issue alerts. We think it will take more than a week for the recovery. The MAXI itself in orbit has no problem and continues the observation. The data will be sent to Tsukuba space center afterwards.
MAXI/GSC has detected a new outburst from Be transient X-ray binary pulsar A0535+262 (Atel #3166). The figure shows the lightcurve folded with 110.2-day orbital period (Moritani 2010) in the 1.5 yr MAXI observations. Orbital phase zero corresponds to the periastron. The current light curve (orange) traces the previous giant outburst (blue) in December 2009 very well. (It may be a little smaller this time). The He I double line indicates a new gas-disk ejection from the Be star (Atel #3176). No strong precursor before MJD55601 (= Feb 9) may indicate that the gas was ejected very recently just before the “He I double line” observation (Feb 5). The short (1.2 yr) recurrent time shows that the Be star has become active.
MAXI/GSC detected a new activity from transient pulsar GX 304-1. The figure shows the lightcurve folded with 132.5-day orbital period. As shown in below figure, the current flux increase is about 1-week earlier than that of the previous outburst within the orbital cycle of 132.5-day period. Thus, the current activity may be a precursor, or an onset of an anomalous giant outburst that occurs out of regular recurrent phase. We have reported this news to Astronomer’s Telegram #3075.
MAXI team reported three detections of the transient events to Astronomer’s Telegram (ATEL) in October, 2010.
2990: Short X-ray Transient Detection by MAXI/GSC Tomida 2010 Oct 31 9:49
2970: MAXI/GSC detects a new activity from Be pulsar A0535+262 Mihara, 2010 Oct 25 21:33
2959: MAXI/GSC detects an X-ray transient MAXI J1409-619 Yamaoka, 2010 Oct 20 11:06
We open daily spectra of ten bright sources today. There is a spectrum plot following light curves and images for each source page. The spectrum is fitted with wabs * power-law model and the parameters are written in the plot. One can download the spectrum, background and response files by clicking “Download spectrum, background and response” below the plot. After extracting the tar.gz file, one can fit the spectrum with your XSPEC software. The sources whose spectrum is available are Crab, Sco X-1, Cen X-3, Her X-1, GX 9+9, GX 9+1, GX 13+1, GX 17+2, GRS 1915+105, and Cyg X-2.
The daily spectrum of Crab, which is available at http://maxi.riken.jp/top/index.php?cid=1&jname=J0534+220
We reported in Atel#2970 (Mihara et al.) that MAXI/GSC detected a new activity from X-ray pulsar A0535+262. The figure shows the recent four light curves folded with 115-day outburst period. The current consecutive activities exhibit the outbursts and precursor events at phases ~0.2 and ~0.95, respectively. The phase zero is taken at MJD 55153.5, which is the periastron passage prior to the previous giant outburst.
The MAXI/GSC has detected a faint X-ray transient, MAXI J1409-619, with a position of (R.A., Dec) = (212.26, -61.95) = (14h09m02s.4, -61d57m00s.0) (J2000) with a typical error of about 0.2 degrees.
The 4-10 keV images and light curves taken by GSC are shown below. Detailed results will be reported in an ATel. The bright dMe star 1RXS J141108.2-615601 is marginally within an error circle, but follow-up observations are required to solve the nature of this source.
MAXI team reported three detections of the transient events to Astronomer’s Telegram (ATEL) in September, 2010.
- 2873: MAXI/GSC detection of a new hard X-ray transient source MAXI J1659-152 Negoro, 2010 Sep 25 16:12
- 2842: Short X-ray Transient detected by MAXI/GSC Morii, 2010 Sep 13 8:26
- 2836: MAXI/GSC detection of a possible flare from TWA-7 Morii, 2010 Sep 9 3:33
We reported in ATEL#2873 (Negoro et al.) that MAXI/GSC detected a new X-ray transient, MAXI J1659-152 at (RA,Dec)=(264.79, -15.27) (J2000), whose position is consistent with the location of GRB100925A reported in GCN#11296 (Mangano et al.).
The GSC light curve since UT 2010-09-21 00:00 (MJD 55460.0) is shown in the below. The X-ray brightening seems to start around 2010-09-25 00:00 (MJD 55464.0) . The latest light-curve data will be updated on the data-product web page.