MAXIMASTER - MAXI Master Catalog

Overview

The MAXIMASTER database table records high-level information of the Monitor of All-sky X-ray Image (MAXI) observations and provides access to the data archive. MAXI is a Japanese experiment located at the International Space Station (ISS), designed to continuously monitor, through a systematic survey, X-ray sources as the ISS orbits Earth. MAXI was launched by the space shuttle Endeavour on 2009 July 16, then mounted on port No. 1 on JEM-EF on July 24. After the electric power was turned on, MAXI started nominal observations on 2009 August 3.

Catalog Bibcode

2009PASJ...61..999M

Bulletin

The MAXIMASTER database table was last updated on 12 December 2024.

References

The MAXI Mission on the ISS: Science and Instruments for Monitoring All-Sky X-Ray Images
Matsuoka, M, Kawasaki, K., Ueno, S., Tomida, H., Kohama, M., Suzuki, M.,
Adachi, Y., Ishikawa, M., Mihara, T., Sugizaki, M. et al.
   <Publ. Astron. Soc. Japan, Vol. 61, 999 (2009)>
   =2009PASJ...61..999M

Provenance

The MAXI data are a copy of the MAXI data processing; the output of which is hosted at the DARTS archive located at ISAS (https://darts.isas.jaxa.jp/astro/maxi/). This catalog is then generated at the HEASARC by collecting high-level information from the data and is updated regularly during operation.

Description

MAXI is comprised of two highly sensitive X-ray detectors, the Gas Slit Camera (GSC, Mihara T. et al. PASJ, 63, S623, 2011) and the Solid-state Slit Camera (SSC, Sugizaki M. et al. PASJ, 63, S635,2011). MAXI is operated with two bit-rates, medium and low. The low-bit-rate data is always available, while there are periods when the medium bitrate is not available. The observations with the SSC are only made when the medium bitrate is available.

The MAXI science data processing assigns position to the events, calibrates the energy gain, as well as discards unwanted time intervals and/or data taken when specific instruments and orbital parameters are out of bounds. The output of the processing are the cleaned event files that are part of the public archive.

Since MAXI is scanning continuously the whole sky, the cleaned event files are organized in interval of one day and within the sky is divided in equal square degree. The sky division uses the Hierarchical Equal Area isoLatitude Pixelization of a sphere method known as HEALPix. The sky is divided in 768 regions (tiles), each of 7.329 x 7.3298 deg² with a pre-set Right Ascension and Declination.

The SSC is composed of horizontal (SSC-H) and zenithal (SSC-Z) arrays, therefore within a day there two sets of the 768 tiles: one for the H array and one for the Z array. The GSC is composite by 12 counters that are merged when creating the cleaned event files. Also for the GSC there are two sets of the 768 tiles: one for the low bit rate and one for the medium bit rate. If a tile does not contain events, the file for that specific tile is not created. Therefore within a day is possible that not all the tiles are present in each of the SSC or GSC data set.

Each row of the MAXIMASTER database table corresponds to a specific day and tile and records whether or not the corresponding event files for GSC (med and low) or SSC (Z or H) are present.

Parameters

Unique_ID
This parameter contains a unique row identifier for the database table. It is a composite 8-digit number. The first 5 digits are the day in MJD (Modified Julian Date), and the last 3 digits are the tile number.

ObsID
This parameter contains the identifier for the directory where the data are located. It is a numerical value corresponding to the day in MJD.

Time
The start time of the observation. The data have been divided into 1-day observations. This time corresponds to the start of the day.

End_Time
The end time of the observation. The data have been divided into 1-day observations. This time corresponds to the end of the day.

RA
The nominal Right Ascension of the center of the region (tile). The sky has been divided in regions (tiles) with specific RA and Dec that are repeated for each observing day. The same RA is therefore found in each observing day.

Dec
The nominal Declination of the center of the region (tile). The sky has been divided in regions (tiles) with specific RA and Dec that are repeated for each observing day. The same Dec is therefore found in each observing day.

LII
The nominal Galactic Longitude of the center of the tile.

BII
The nominal Galactic Latitude of the center of the tile.

Tile_Number
This parameter corresponds to the sky tile number. The values range from 000-767.

GSCMed_Flag
This parameter flags whether or not the event data taken with the GSC medium bit rate are present for this observation day and sky region. Value: 0=not present; 1=present.

GSCLow_Flag
This parameter flags whether or not the event data taken with the GSC low bitrate are present for this observation day and sky region. Value: 0=not present; 1=present.

SSCMedH_Flag
This parameter flags whether or not the event data taken with the SSC H-array are present for this observation day and sky region. Value: 0=not present; 1=present.

SSCMedZ_Flag
This parameter flags whether or not the event data taken with the SSC Z-array are present for this observation day and sky region. Value: 0=not present; 1=present.

Info_From
This parameter records from which file the time and position information are read. The values of gsc_med, gsc_low, ssch, and sscz indicate that the time and position are taken from the event data of the GSC medium or low bitrate or from the SSC H-array or Z-array. If set to None, this indicates that no event data are present for any of the GSC and SSC detectors, and the time is set to the day boundaries and the position to the center of the tile number.

Processing_Date
This parameter records the date when the data were last processed.

Processing_Version
This records the version of the processing script used in the pipeline to generate the data products for the observation.

Contact Person

Questions regarding the MAXIMASTER database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:30:57 EDT