SWUVOTSSOB - Swift/UVOT Serendipitous Source Catalog, v1.1: Observations IDs

Overview

The first version of the Swift UVOT Serendipitous Source Catalog (UVOTSSC) provides positions and magnitudes, as well as errors and upper limits of confirmed sources, for observations taken from the start of operations in 2005 until October 1st of 2010.

The first version of the UVOTSSC has been produced by processing the image data obtained from the Swift Ultraviolet and Optical Telescope (UVOT). The data processing was performed at the Mullard Space Science Laboratory (MSSL, University College London, U.K.) using Swift FTOOLS from NASA's High Energy Astrophysics Software package (HEASoft-6.11), with some customizing of the UVOT packages in order to get more complete source detection and to properly apply quality flags to those sources that were detected within the UVOT image artifacts. The total number of observations with 17'x17' images used for version 1 of the catalog is 23,059, giving 6,200,016 sources in total, of which 2,027,265 have multiple entries in the source table because they have been detected in more than one observation. Some sources were only observed in one filter. The total number of entries in the source table is 13,860,568. The S/N ratio for all sources exceeds 5 in at least one UVOT filter, the rest of the filters having a S/N greater than 3.

One Swift ObsID can consist of one or more images, which for this catalog have been summed, yielding the quoted total exposure times. The original UVOT images can be found in the on-line archives at MAST, and in the Swift archives at http://swift.ac.uk/ and at the HEASARC (http://heasarc.gsfc.nasa.gov/W3Browse/all/swiftmastr.html), using the ObsID as the search key. For higher temporal resolution, the original images need to be used because the catalog data herein are summed over all of the individual images within an ObsID.

The upper limits per filter for the summed images are constructed for each ObsID because the sensitivity hardly varies over the detector. Usually the images within one ObsID share the same pointing, however, whereas the quoted upper limits always apply for sources near the pointing direction given, if the images had small offsets in pointing they may not apply to sources near the edge of the summed image, which is typically about 8 arcminutes from the quoted pointing direction.

U, B, V, UVW2, UVM2 and UVW1 refer to the filter bandpasses defined in the UVOT Filterwheel section of the MSSL documentation at http://www.mssl.ucl.ac.uk/www_astro/uvot/uvot_instrument/filterwheel/filterwheel.html.

This HEASARC table contains version 1.1 of the Swift UVOT table of observations in which the sources in the source table were detected and contains the details of 23,059 Swift UVOT observations. The HEASARC has changed the names of many of the parameters from those given in the original table. In such cases, we have listed the original names in parentheses at the end of the parameter descriptions given below. There is a related table which lists the 13,860,568 source detections that is available at the HEASARC as the SWUVOTSSC table.

Catalog Bibcodes

2014Ap&SS.354...97Y
2014styd.confE..37P

References

Serendipitous UV source catalogues for 10 years of XMM and 5 years of Swift
    Yershov V.N.
    <Astrophys. Space Sci. 354, 97 (2014)>
    =2014Ap&SS.354...97Y
The Swift UVOT Serendipitous Source Catalogue - UVOTSSC (2005-2010), Version 1
    Page M., Yershov V., Breeveld A., Kuin N.P.M., Mignani R.P.,
    Smith P.J., Rawlings J.I., Oates S.R., Siegel M., Roming P.W.A.
   <Proc. Swift 10 Years of Discovery, held 2-5 December 2014 at
    La Sapienza University, Rome, Italy, 37 (2015)>
   =2015yCat.2339....0Y
   =2014styd.confE..37P (2015arXiv150306597P)

Provenance

This table was created by the HEASARC in May 2017 based upon the CDS Catalog II/339 file summary.dat.

Parameters

Obs_Sum_Number
This parameter provides a reference number for the Swift UVOT observation, and can be used to link to the sources detected therein which are listed in the related table SWUVOTSSC. (N_SUMMARY)

ObsID
The unique Swift observation identification number corresponding to the observation.

Name
The name of the Swift target of the specified observation as given by the original proposer of the observation. (TARGET_ID)

RA
The Right Ascension of the UVOT pointing direction in the selected equinox. This was given in J2000.0 degrees to a precision of 10^-6 degrees in the original table. (RA_PNT)

Dec
The Declination of the UVOT pointing direction in the selected equinox. This was given in J2000.0 degrees to a precision of 10^-6 degrees in the original table. (DEC_PNT)

LII
The Galactic Longitude of the UVOT pointing direction.

BII
The Galactic Latitude of the UVOT pointing direction.

Time
The date and time (in UT) when the first exposures for this observation started to be taken. Most observations are completed within a few days of this date. (DATE_MIN)

Filters
The list of filters which were used in this observation.

UVOT_Position_Angle
The position angle for the telescope pointing, in degrees. (PA_PNT)

UVW2_Exposure
The total summed exposure time, in seconds, in the specified observation and filter combination. (EXP_UVW2)

UVM2_Exposure
The total summed exposure time, in seconds, in the specified observation and filter combination. (EXP_UVM2)

UVW1_Exposure
The total summed exposure time, in seconds, in the specified observation and filter combination. (EXP_UVW1)

U_Exposure
The total summed exposure time, in seconds, in the specified observation and filter combination. (EXP_U)

B_Exposure
The total summed exposure time, in seconds, in the specified observation and filter combination. (EXP_B)

V_Exposure
The total summed exposure time, in seconds, in the specified observation and filter combination. (EXP_V)

UVW2_Number_Sources
The total number of sources detected in the specified observation and filter combination. (NSOURCES_UVW2)

UVM2_Number_Sources
The total number of sources detected in the specified observation and filter combination. (NSOURCES_UVM2)

UVW1_Number_Sources
The total number of sources detected in the specified observation and filter combination. (NSOURCES_UVW1)

U_Number_Sources
The total number of sources detected in the specified observation and filter combination. (NSOURCES_U)

B_Number_Sources
The total number of sources detected in the specified observation and filter combination. (NSOURCES_B)

V_Number_Sources
The total number of sources detected in the specified observation and filter combination. (NSOURCES_V)

UVW2_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the Vega photometry system. (VEGAMAG_LIM_UVW2)

UVM2_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the Vega photometry system. (VEGAMAG_LIM_UVM2)

UVW1_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the Vega photometry system. (VEGAMAG_LIM_UVW1)

Umag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the Vega photometry system. (VEGAMAG_LIM_U)

Bmag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the Vega photometry system. (VEGAMAG_LIM_B)

Vmag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the Vega photometry system. (VEGAMAG_LIM_V)

UVW2_AB_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the AB photometry system. (ABMAG_LIM_UVW2)

UVM2_AB_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the AB photometry system. (ABMAG_LIM_UVM2)

UVW1_AB_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the AB photometry system. (ABMAG_LIM_UVW1)

U_AB_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the AB photometry system. (ABMAG_LIM_U)

B_AB_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the AB photometry system. (ABMAG_LIM_B)

V_AB_Mag_Detlim
The three-sigma detection limiting magnitude in the specified filter for this observation, in the AB photometry system. (ABMAG_LIM_V)

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:35:39 EDT