SWBATMONTR - Swift BAT Transient Monitoring Catalog

Overview

The SWBATMONTR database table records high-level information of the lightcurves from the sources monitored with the Burst Alert Telescope (BAT) on board of Swift.

The Swift/BAT Monitoring Program is aimed at (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of lightcurves of more than 1000 sources spanning the entire Swift lifetime.

Swift is a NASA mission with international participation dedicated to the gamma-ray burst study. It carries three instruments. The BAT is the large field of view instrument and operates in the 10-300 keV energy band; and two narrow field instruments, XRT and UVOT, that operate in the X-ray and UV/optical regime, respectively. The BAT monitoring the sky in the field of view and provides alerts when detecting a burst of flux coming from a source in the field of view.

Catalog Bibcode

2013ApJS..209...14K

Bulletin

The SWBATMONTR database table was last updated on 3 December 2024.

References

The Swift/BAT Hard X-Ray Transient Monitor.
    Krimm, H.A. et al., 2013, The Astrophysical Journal Supplement, Volume
    209, Issue 1, article id. 14, 33 pp. (2013).
   =2013ApJS..209...14KA

Provenance

The BAT monitoring lightcurves are generated by the BAT team over the course of the Swift mission. The HEASARC ingests these data in the archive and generates this database table by collecting high-level information from the data. The lightcurves are renamed to use a consistent naming convention, and the FITS header is updated by adding standard FITS keywords.

Description

The BAT monitoring lightcurves are generated for a group of sources included in the "monitoring" source list kept and updated by the BAT team. The list includes most galactic sources known to be variable and undergo into outburst, bright extragalactic sources or known to show variability on long time scale and other interesting sources. Two types of FITS lightcurves are generated for each source. Their the naming convention is swbjHHMM_mXDDMM_ZYYMM, where X if the source is in the north part of the sky ("p") or in the south part ("m") and Z is either "o" for orbit or "d" for day. The orbit lightcurve ("o") has each point calculated using all data collected over a satellite orbit, instead each point in the day lightcurve ("d") uses all data collected over one observing day. The units of the rates in the lightcurve are count/s/cm² but in other BAT products, the rate are reported as count/s (or as count/s/pixel). The conversion between the units is 1 count/s/cm² = 0.16 count/s. A plot of the "d" lightcurve is also included in the archive. During the Swift operation the lightcurves are updated in the HEASARC archive every month. Each row of the database table contains information for a specific source monitored by the BAT. It includes the average rate and error, the max rate and the standard deviation for the lightcurve by day and by orbit. These rates are calculated using all points present in the lightcurves at the time of the ingest and the results are updated in the database each each ingest.

Parameters

Name
This is the source designation. The value is retrieved from the lightcurve from the OBJECT keyword.

Catalog_Name
This is the source name in the master BAT. The nomenclature for the fields is "SWIFT JHHMM.m+DDMM" and it is stored in the lightcurve keyword CATNAM.

Time
The start time of the lightcurves. This time corresponds to the first time in the "o" lightcurve.

End_Time
The end time of the lightcurves. This time corresponds to the last time in the "o" curve where is added the bin exposure.

RA
Right Ascension of the source monitored. The value is retrieved from the RA_OBJ keyword on the lightcurve.

Dec
Declination of the source monitored. The value is retrieved from the DEC_OBJ keyword on the lightcurve.

LII
Galactic Longitude of the pointing position. This parameter has been added by the HEASARC and is calculated from the J2000 pointing position.

BII
Galactic Latitude of the source position. This parameter has been added by the HEASARC and is calculated from the J2000 pointing position.

Day_Rate
Records the average rate of the "d" (day-binned) lightcurve using all the points present in the RATE column of the data file. The rate are provided as count/s/cm².

Day_Rate_Error
Records the average error of the "d" (day-binned) lightcurve using all the points present in the ERROR column of data file. The rate are provided as count/s/cm².

Day_Rate_Stdv
Records the rate standard deviation of the "d" (day-binned) lightcurve using all the points present in the RATE column of the data file. The rate are provided as count/s/cm².

Day_Rate_Max
Records the maximum value of the RATE column in the "d" (day-binned) lightcurve. The rate are provided as count/s/cm².

Orb_Rate
Records the average rate of the "o" (orbit-binned) lightcurve using all the points present in the RATE column of the data file. The rate are provided as count/s/cm².

Orb_Rate_Error
Records the average error of the "o" (orbit-binned) lightcurve using all the points present in the ERROR column of data file. The rate are provided as count/s/cm².

Orb_Rate_Stdv
Records the rate standard deviation of the "o" (orbit-binned) lightcurve using all the points present in the RATE column of the data file. The rate are provided as count/s/cm².

Orb_Rate_Max
Records the maximum value of the RATE column in the "o" (orbit-binned) lightcurve. The rate are provided as count/s/cm².

Root_Filename
Records the root of the file name of the FITS and PNG lightcurves.

Source_Type
Records a broad classification of the source, e.g. whether is a binary or AGN. Not all the sources have an associated source type.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:35:26 EDT