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MAXI Data


Monitor of All-sky X-ray Image (MAXI) Begins Public Data Distribution

On January 13, 2010, the Monitor of All-sky X-ray Image (MAXI) team started public data release at the MAXI homepage , operated at RIKEN Advanced Science Institute.

MAXI is a collaboration between Japan Aerospace Exploration Agency (JAXA) and RIKEN. The MAXI operation and science data analysis are conducted by a group of scientists (the MAXI team) from JAXA, RIKEN, Osaka University, Tokyo Institute of Technology, Aoyama Gakuin University, Nihon University, Kyoto University, University of Miyazaki, and Chuo University.

In August 2009, MAXI started the monitoring of X-ray brightness and color of the entire sky as the first astronomical instrument attached to the Japan Experiment Module (JEM-Kibo) Exposed Facility of the International Space Station (ISS). During the nominal mission life of five years, the MAXI public data are released through the MAXI homepage at RIKEN. After completion of the MAXI mission, the public data will be permanently stored at and distributed from the Data ARchive and Transmission System (DARTS) operated by JAXA Institute of Space and Astronautical Science (ISAS). Also, MAXI public data products will be mirrored at NASA's High Energy Astrophysics Science Archive Research Center ( HEASARC ) in future.

Table 1 shows the MAXI Public Data Release Plan. What is already released are light curves and images of the relatively bright known sources which MAXI has been monitoring since August 15, 2009. Currently, those data of approximately 100 sources are available, which we are planning to increase up to ~1000.

You are able to browse and download the MAXI public data at the MAXI homepage . To receive MAXI Alert Mails, click "Mailing List" from the top menu of the MAXI homepage, choose mailing lists of your interests, and resister your e-mail address. You will receive MAXI alert emails of the categories you chose.

Table 1. MAXI Public Data Release Plan (as of February 26, 2010)
Status MAXI Product Release Method Latency
(from Observation
to Release)
Open Nova & Burst Alert
(transmitted after
human verification)
Existing Alert Systems
( ATel, GCN )
hours
to days
Will start
Spring
2010
Nova & Burst Alert
(transmitted after
software verification)
MAXI Alert Mailing List 1 minutes
to hours
Open For bright known sources
Light Curve
Image
MAXI Homepage
(Light Curves)
1 day
Will start
Summer
2010
For bright known sources
Energy Spectrum#
MAXI Homepage 1 day
Will start
by End of
2010
For any sky & time region
Light Curve
Image
MAXI Homepage 1 day
Will start
by End of
2010
For any sky & time region
Energy Spectrum#
MAXI Homepage 1 day
#: Provided together with an instrument response file and a background spectrum file.

As an example of what are available at the MAXI homepage, let's browse light curves and images of the black hole candidate XTE J 1752-223, which emerged on October 23, 2009.

In the top page menu of the MAXI homepage , click "Data Product" to move to the Source Search page . Then click "Source List" in the left menu bar to display the list of sources of which data already public.

The source names are listed in alphabetical order. Scroll the page down to the "X" section, and find the entry "XTE J 1752-223". Click the source name "XTE J 1752-223" to move the dedicated page as shown in figure 1. There you will find X-ray light curve plots with a time range from 15 August 2009 to today, and four X-ray images (for four different energy bands) created from the most recent one-day-exposure MAXI data. Under the X-ray images, there are dialog boxes, with which you are able to specify any time range and download numerical data of light curves in ASCII text format.

Figure 1. Data Page of XTE J 1752-223
figure1

The release of spectra has not yet started. When we will be able to obtain instrument response files and background files of acceptable quality, the MAXI spectrum files will be released together with response and background files. You will be able to use those files in the spectra analysis using XSPEC, a popular spectral analysis package.

As we said above, currently we are releasing data of only relatively bright known sources. By the end of 2010, we are planning to open a new web interface, which enable you to specify arbitrary sky regions to download the corresponding light curves, images and spectra, which are calculated on-the-fly.

To obtain information on the MAXI mission and instrument, please visit the Publications page of the MAXI homepage. The latest status of MAXI is posted to the News page ( English , Japanese ).

JAXA ISS Science Project Office, Shiro Ueno

February 2010

Related Link:
http://www.jaxa.jp/press/2009/11/20091126_maxi_e.html ( MAXI First All-Sky Image )

Last Modified: 27 August 2013