VLBI observations of gamma-ray-quiet active galactic nuclei: Comparing radio-core brightness temperatures

被引：28
作者：
Tingay, SJ
Murphy, DW
Lovell, JEJ
Costa, ME
McCulloch, P
Edwards, PG
Jauncey, DL
Reynolds, JE
Tzioumis, AK
King, EA
Jones, DL
Preston, RA
Meier, DL
van Ommen, TD
Nicolson, GD
Quick, JFH
机构：
[1] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
[2] Univ Tasmania, Hobart, Tas 7001, Australia
[3] Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan
[4] CSIRO, Australia Telescope Natl Facil, Epping, NSW 2121, Australia
[5] Hartebeesthoek Radio Astron Observ, ZA-1740 Krugersdorp, South Africa
来源：
ASTROPHYSICAL JOURNAL | 1998年 / 497卷 / 02期
关键词：
galaxies; active; jets; gamma-rays; observations; radio continuum; techniques; interferometric;
D O I：
10.1086/305494
中图分类号：
P1 [天文学];
学科分类号：
0704 ;
摘要：
We present VLBI and Australia Telescope Compact Array images and derive source-frame radio-core brightness temperatures for three prominent, flat-spectrum extragalactic radio sources, notable because they have not been detected as gamma-ray sources with the EGRET instrument. Radio-core brightness temperatures are discussed as an indicator of relativistic beaming. A comparison of source-frame radio-core brightness temperatures for EGRET-identified and gamma-ray-quiet, radio-loud AGNs shows that a wide range in beaming properties is likely to exist, independent of the level of gamma-ray emission. This comparison suggests that, although there is a strong relationship between radio emission and gamma-ray emission in EGRET-identified AGNs, and many EGRET-identified AGNs show evidence for relativistic beaming, there is little evidence for a one-to-one correspondence between the strength of gamma-ray emission and the degree of beaming of the radio emission.
引用
收藏
页码：594 / 600
页数：7
相关论文
共 37 条
  • [1] THE COLLECTIVE EMISSION OF ELECTROMAGNETIC-WAVES FROM ASTROPHYSICAL JETS - LUMINOSITY GAPS, BL-LACERTAE OBJECTS, AND EFFICIENT ENERGY-TRANSPORT
    BAKER, DN
    BOROVSKY, JE
    BENFORD, G
    EILEK, JA
    [J]. ASTROPHYSICAL JOURNAL, 1988, 326 (01) : 110 - 124
  • [2] SEST observations of southern flat-spectrum radio sources
    Beasley, AJ
    Conway, JE
    Booth, RS
    Nyman, LA
    Holdaway, M
    [J]. ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 1997, 124 (03): : 469 - 474
  • [3] RELATIVISTIC JETS AS COMPACT RADIO-SOURCES
    BLANDFORD, RD
    KONIGL, A
    [J]. ASTROPHYSICAL JOURNAL, 1979, 232 (01) : 34 - 48
  • [4] A CATALOG OF RADIO-SOURCES TO BE OCCULTED BY COMETS P/HALLEY AND P/GIACOBINI-ZINNER
    DEPATER, I
    SCHLOERB, FP
    JOHNSON, AH
    [J]. ASTRONOMICAL JOURNAL, 1985, 90 (05) : 846 - 868
  • [5] THE FIRST ENERGETIC GAMMA-RAY EXPERIMENT TELESCOPE (EGRET) SOURCE CATALOG
    FICHTEL, CE
    BERTSCH, DL
    CHIANG, J
    DINGUS, BL
    ESPOSITO, JA
    FIERRO, JM
    HARTMAN, RC
    HUNTER, SD
    KANBACH, G
    KNIFFEN, DA
    KWOK, PW
    LIN, YC
    MATTOX, JR
    MAYERHASSELWANDER, HA
    MCDONALD, L
    MICHELSON, PF
    VONMONTIGNY, C
    NOLAN, PL
    PINKAU, K
    RADECKE, HD
    ROTHERMEL, H
    SREEKUMAR, P
    SOMMER, M
    SCHNEID, EJ
    THOMPSON, DJ
    WILLIS, T
    [J]. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1994, 94 (02) : 551 - 581
  • [6] RELATIVISTIC BULK MOTION IN ACTIVE GALACTIC NUCLEI
    GHISELLINI, G
    PADOVANI, P
    CELOTTI, A
    MARASCHI, L
    [J]. ASTROPHYSICAL JOURNAL, 1993, 407 (01) : 65 - 82
  • [7] Equipartition Doppler factors for a sample of active galactic nuclei
    Guijosa, A
    Daly, RA
    [J]. ASTROPHYSICAL JOURNAL, 1996, 461 (02) : 600 - 608
  • [8] HARTMAN RC, 1998, AIP C P, V410, P307
  • [9] Quasars, blazars, and the gamma-ray sky
    Impey, C
    [J]. ASTRONOMICAL JOURNAL, 1996, 112 (06) : 2667 - 2683
  • [10] NEW BLAZARS DISCOVERED BY POLARIMETRY
    IMPEY, CD
    TAPIA, S
    [J]. ASTROPHYSICAL JOURNAL, 1988, 333 (02) : 666 - 672
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