Browse
this table...

TARTARUS - Tartarus: Reduced ASCA AGN Data (Version 3.1)

HEASARC
Archive

Overview

The Tartarus database contains the results of a detailed but systematic analysis of ASCA observations of active galactic nuclei (AGN). It contains source and background events files, spectra, ancillary response files and response matrices, images, and assorted light curves for a large number of ASCA AGN observations. Spectral fit results are done by automatic XSPEC fitting. This database table allows easy access to reduced AGN data for the whole community, allowing the maximum scientific return from the data. Availability of publishable light curves, images, and spectra (which can also be readily re-fitted) should be particularly valuable to astronomers with little direct experience in the reduction of X-ray data.

Version 3.1 has been created by analyzing all ASCA observing sequences with targets designated as AGN, as indicated by a leading "7" in the ASCA observing sequence number. Version 3.1 contains products for all 611 observing sequences designated as AGN observations. This is a significant improvement over Versions 1 and 2. Moreover, the 611 sequences for which products are available are complete in the sense that either the target object was not detected (in which case an upper limit on GIS2 source counts is given) or the intended AGN target was detected and the data were fully analyzed. In order to obtain the most accurate background subtraction and minimize contamination from any nearby sources, version 3.1 makes more use of custom extraction regions than previous versions. It is expected that version 3.1 will be replaced when the final ASCA calibration is completed.


Catalog Bibcode

2001AIPC..599..991T

References

More information about the Tartarus project can be obtained from
    http://heasarc.gsfc.nasa.gov/FTP/asca/data/tartarus/
The data analysis method is described in detail at
    http://heasarc.gsfc.nasa.gov/FTP/asca/data/tartarus/docsv3/analysis.html

Provenance

This database table has been created by the Tartarus Team, and they, rather than Imperial College London or the HEASARC, are responsible for the contents. It was ingested by the HEASARC in August, 2005.

Data Products

The Tartarus data products consist of the following:
     (a) a web page which contains a summary of the results,
     (b) an "all" tar file containing the complete reduced data set,
     (c) an "image" tar file containing only imaging data,
     (d) a "spectral" tar file containing only spectral data,
     (e) a "timing" tar file containing only timing data, and
     (f) text files containing descriptions of the products for each sequence.
For objects that are not detected, the image, spectral, and timing tar files are not available. These are objects for which the detection significance is less than 5.

Parameters

Seq_Num
The ASCA sequence number of the observation. ASCA AGN sequences begin with the number 7.

Name
The Tartarus designation of the target object.

ASCA_Name
The ASCA designation of the target object, as specified by the OBJECT keyword in the FITS header of the attitude file. (Note that this has no embedded blanks.)

RA
The Right Ascension of the target object in the selected equinox.

Dec
The Declination of the target object in the selected equinox.

LII
The Galactic Longitude of the target object.

BII
The Galactic Latitude of the target object.

Start_Time
The date and time (UT) of the start of the observation.

Elapsed_Time
The elapsed time (in seconds) of the observation by the SIS0 detector.

Exposure
The total time (in seconds) that the target object was exposed, in the SIS0 detector.

CCD_Mode
The number of chips (1, 2, or 4) used per SIS detector for the observation. This is also referred to as the SIS clocking mode.

Data_Mode
The telemetry mode in which most data for the observation were collected. BRIGHT2 mode data are converted from FAINT mode data, as are some BRIGHT mode data.

SIS_Low
The lower energy boundary (in keV) for SIS data. The "effective" event threshold for each SIS instrument is the higher value between the actual event threshold and the lower discriminator value. If the effective event threshold changed during the observation, then the lowest energy used for the SIS data should be 0.6 keV; otherwise, it is 0.5 keV.

Detection_Sig
The significance of the detection of the target object in the GIS2 sky image. A detection significance of 5 sigma corresponds to a false detection probability of 2.87e-7. Objects with a detection significance of at least 5 sigma are classified as detections.

Detection_Flag
This flag is set to 'Y' to indicate detection and 'N' otherwise. Objects with a detection significance of at least 5 sigma are classified as detections.

SIS0_Full
The SIS0 full-band (sis_low - 10 keV), background-subtracted count rate (counts s-1) in the source region.

SIS0_Soft
The SIS0 soft-band (sis_low - 2 keV), background-subtracted count rate (counts s-1) in the source region.

SIS0_Hard
The SIS0 hard-band (2 - 10 keV), background-subtracted counting rate (counts s-1) in the source region.

SIS1_Full
The SIS1 full-band (sis_low - 10 keV), background-subtracted count rate (counts s-1) in the source region.

SIS1_Soft
The SIS1 soft-band (sis_low - 2 keV), background-subtracted count rate (counts s-1) in the source region.

SIS1_Hard
The SIS1 hard-band (2 - 10 keV), background-subtracted counting rate (counts s-1) in the source region.

GIS2_Full
The GIS2 full-band (0.75 - 10 keV), background-subtracted count rate (counts s-1) in the source region.

GIS2_Hard
The GIS2 hard-band (2 - 10 keV), background-subtracted count rate (counts s-1) in the source region.

GIS3_Full
The GIS3 full-band (0.75 - 10 keV), background-subtracted count rate (counts s-1) in the source region.

GIS3_Hard
The GIS3 hard-band (2 - 10 keV), background-subtracted count rate (counts s-1) in the source region.

Hard_NH
The best-fitting column density (cm-2) from an absorbed power-law model fitted over the 2-10keV range (excluding 5-7.5 keV). The absorber was modeled using the WABS model in XSPEC and is assumed to be at zero redshift.

Hard_Gamma
The best-fitting photon-index from an absorbed power-law model fitted over the 2-10keV range (excluding 5-7.5 keV).

Hard_Flux
The SIS0 flux (erg cm-2 s-1) of the best-fitting absorbed power-law model fitted over the 2-10keV range (excluding 5-7.5 keV).

Red_Chi_Sq
The reduced chi-squared of the best-fitting absorbed power-law model fitted over the 2-10keV range (excluding 5-7.5 keV).

DoF
The degrees of freedom of the absorbed power-law model fitted over the 2-10keV range (excluding 5-7.5 keV).

Veron_Num
The number of Veron 2001 objects within the GIS field-of-view.

Veron_Name
The name of the Veron 2001 object that is closest to the target object.

Veron_RA
The Right Ascension (J2000) of the Veron 2001 object that is closest to the target object.

Veron_Dec
The Declination (J2000) of the Veron 2001 object that is closest to the target object.

Veron_Redshift
The redshift of the Veron 2001 object that is closest to the target object.

Veron_Type
The classification of the Veron 2001 object that is closest to the target object.


Contact Person

Detailed questions about the Tartarus project and database should be addressed to the Tartarus Team at tartarus@athena.gsfc.nasa.gov.

Questions regarding the HEASARC database implementation of the Tartarus database and the Browse interface can be addressed to the HEASARC User Help Desk at http://heasarc.gsfc.nasa.gov/cgi-bin/Feedback.



Page Author: Browse Software Development Team
Last Modified: 27-Jan-2014