AGILEUPVAR - Updated AGILE Catalog of Bright Gamma-Ray Sources and Variability

Overview

This table contains some of the results from a variability study of a sample of bright gamma-ray (30 MeV - 50 GeV) sources. This sample is an extension of the first AGILE catalog of gamma-ray sources (1AGL), obtained using the complete set of AGILE observations in pointing mode performed during a 2.3 year period from July 9, 2007 until October 30, 2009. The dataset of AGILE pointed observations covers a long time interval and its gamma-ray data archive is useful for monitoring studies of medium-to-high brightness gamma-ray sources. In the analysis reported here, the authors used data obtained with an improved event filter that covers a wider field of view, on a much larger (about 27.5 months) dataset, integrating data on observation block (OB) time scales, which mostly range from a few days to thirty days.

The data processing resulted in a better characterized source list than 1AGL was, and includes 54 sources, 7 of which are new high galactic latitude (|b_II_|>= 5 degrees) sources, 8 are new sources on the galactic plane, and 20 sources are from the previous catalogue with revised positions. Eight 1AGL sources (2 high-latitude and 6 on the galactic plane) were not detected in the final processing either because of low OB exposure and/or due to their position in complex galactic regions. The reference paper reports the results in a catalog of all the detections obtained in each single OB, including the variability results for each of these sources. In particular, the authors found that 12 sources out of 42 or 11 out of 53 are variable, depending on the variability index used, where 42 and 53 are the number of sources for which these indices could be calculated. Seven of the 11 variable sources are blazars, the others are the Crab pulsar+nebula, LS I +61 303, Cyg X-3, and 1AGLR J2021+4030.

This HEASARC table contains 54 AGILE-detected sources and the main parameters of their maximum significance (defined by sqrt(TS)) detections: for each source, the name, coordinates, the sqrt(TS) value as a measure of the detection significance, the E > 100 MeV flux, the four variability indices described in Section 5 of the reference paper, the number of detections, the confirmed counterparts and source class, if any, and other possible associations ordered according to the angular distance from the AGL source are given. These data are listed in Table 5a of the reference paper. This HEASARC table does not contain the list of fluxes for these sources as measured in all of the relevant individual OBs (Table 5b in the reference paper). This latter is obtainable from the CDS: http://cdsarc.u-strasbg.fr/ftp/cats/J_A+A/558/A137/table5b.dat.

Catalog Bibcode

2013A&A...558A.137V

References

An updated list of AGILE bright gamma-ray sources and their variability in
pointing mode.
    Verrecchia F., Pittori C., Chen A.W., Bulgarelli A., Tavani M.,
    Lucarelli F., Giommi P., Vercellone S., Pellizzoni A., Giuliani A.,
    Longo F., Barbiellini G., Trifoglio M., Gianotti F., Argan A.,
    Antonelli L.A., Caraveo P., Cardillo M., Cattaneo P.W., Cocco V.,
    Colafrancesco S., Contessi T., Costa E., Del Monte E., De Paris G.,
    Di Cocco G., Di Persio G., Donnarumma I., Evangelista Y., Fanari G.,
    Feroci M., Ferrari A., Fiorini M., Fornari F., Fuschino F., Froysland T.,
    Frutti M., Galli M., Labanti C., Lapshov I., Lazzarotto F., Liello F.,
    Lipari P., Mattaini E., Marisaldi M., Mastropietro M., Mauri A., Mauri F.,
    Mereghetti S., Morelli E., Moretti E., Morselli A., Pacciani L., Perotti F.,
    Piano G., Picozza P., Pilia M., Pontoni C., Porrovecchio G., Prest M.,
    Primavera R., Pucella G., Rapisarda M., Rappoldi A., Rossi E., Rubini A.,
    Sabatini S., Santolamazza P., Sotta P., Stellato S., Striani E.,
    Tamburelli F., Traci A., Trois A., Vallazza E., Vittorini V., Zanello D.,
    Salotti L., Valentini G.
    <Astron. Astrophys. 558, A137 (2013)>
    =2013A&A...558A.137V        (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in December 2013 based on CDS catalog J/A+A/558/A137 file table5a.dat.

Parameters

Name
The AGILE source designation, using the '1AGL' prefix for sources from the First AGILE source catalog and the J2000 position, viz. '1AGL JHHMM+DDMM', and the '1AGLR' prefix (for sources which were repositioned or are new sources to this updated version of the source catalog) and the J2000 position, viz. '1AGLR JHHMM+DDMM'.

Source_Flag
This parameter contains a value 'FP' indicating that the gamma-ray source position of 1AGL 1836+5923 is consistent with that of the pulsar 2FGL J1836.2+5926.

RA
The Right Ascension of the AGILE source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 seconds of time in the original table.

Dec
The Declination of the AGILE source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the AGILE source.

BII
The Galactic Latitude of the AGILE source.

Error_Radius
The positional uncertainty of the AGILE source (95% confidence), in degrees. This is the 2-D error circle radius statistical error only. The AGILE Team recommends adding a systematic error of 0.1 degrees linearly to this value to get the actual positional uncertainty.

Time
The mid-point date of the observation block in which the maximum source detection significance (as characterized by the largest sqrt(TS) value for the particular source) was obtained.

Sqrt_TS
The maximum value in any of the relevant OBs of the significance of the source detection, sqrt (TS), where TS, the test statistic, is the likelihood ratio. This parameter is determined from a multi-source maximum likelihood (ML) analysis on the updated deep maps. The test statistic TS is defined in equation (2) of Pittori et al. (2009, A&A, 506, 1563).

Flux
The source flux above 100 MeV, in units of 10^-7 photons cm^-2 s^-1 (10^-3 photons m^-2 s^-1), in the observation block in which the maximum source detection significance was obtained.

Flux_Error
The 1-sigma statistical error in the most significant gamma-ray flux measurement of the source, in units of 10^-7 photons cm^-2 s^-1 (10^-3 photons m^-2 s^-1). The AGILE Team recommends adding a systematic error of 10% to this statistical error. The 10% figure is based on Monte Carlo simulations, pre-flight beam tests and in-flight analysis of known sources.

Flux_1AGL
The (E > 100 MeV) source flux reported in the original 1AGL Catalog (Pittori et al. 2009, A&A, 506, 1563), in units of 10^-7 photons cm^-2 s^-1 (10^-3 photons m^-2 s^-1).

V_Index
The McLaughlin V variability index (cf. McLaughlin et al. 1996, ApJ, 473, 763) of the source based on the measurements in the individual OBs, and assuming only statical errors apply. This parameter is discussed in Section 5 of the reference paper. Sources with V < 0.5 were classified as non-variable, with 0.5 <= V < 1 classified as uncertain, and with V >= 1 classified as variable. A high V may indicate either strong flux variations or weak flux variations detected with small flux errors. Moreover, sources with a very small number of detections may also have low V values.

Vsys_3sigma_Index
The McLaughlin V variability index V_sys3s (cf. McLaughlin et al. 1996, ApJ, 473, 763) of the source based on the measurements in the individual OBs and calculated assuming an additional 10% systematic error as well as the statistical error for each measured value. This index will tend to be lower than the index V calculated assuming only statistical errors. This parameter is discussed in Section 5 of the reference paper.

Vsys_2sigma_Index
The McLaughlin V variability index V_sys2s (cf. McLaughlin et al. 1996, ApJ, 473, 763) of the source based on the measurements in the individual OBs, calculated assuming an additional 10% systematic error as well as the statistical error for each measured value, and including the flux measures with 2 <= sqrt(TS) <= 3, for which the AGILE multi-source analysis task ALIKE produces a 95% confidence limit flux upper limit (UL). In this case. the authors set the flux errors to be (F_UL - F_i )/2. This index will tend to be lower than the index V calculated assuming only statistical errors. This parameter is discussed in Section 5 of the reference paper.

Fsys_Index
A fourth variability index F_sys similar to that used in the Fermi 1FGL and 2FGL catalogs, defined to be like a chi-squared and again including a 10% systematic error. In the reference paper, the authors discuss how the reduced values of this parameter, F_sys/N_dof, where N_dof, the number of degrees of freedom is N_det -1, N_det being the number of detections, can be compared it with the 1FGL variability index divided by 10 or to the 2FGL variability index divided by 23 (see their Fig. 12).

Number_Detections
The number of detections of the AGILE source with sqrt(TS) >= 2.

Broad_Type
The gamma-ray source counterpart classification, if known: BL Lac, CWB (colliding Wind Binary), FSRQ (flat-spectrum radio quasar), HMXB (high-mass X-ray Binary), Pulsar or SNR.

Complex_Region_Flag
This parameter contains a value 'Y' indicating that the gamma-ray source 1AGLR 2021+4030 is in a complex region, containing both a pulsar and an SNR.

Counterpart
The counterpart name. This is given for confirmed source matches.

Pulsar_Nebula_Flag
This parameter contains a value 'Y' indicating that the gamma-ray source 1AGL J0535+2205 associated with the Crab has contributions from both the pulsar and the nebula.

One_AGL_Name
The 1AGL source designation, if there was an equivalent source present in the Pittori et al. (2009, A&A, 506, 1563) catalog.

Alt_Names
Other possible association(s) for the AGILE source ordered according to their angular distances from the AGL source.

Class
The HEASARC Browse object classification based on the value of the broad_type parameter.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:24:09 EDT