Hubble space telescope imaging and polarimetry of NGC 5128 (Centaurus A)

被引:44
作者
Schreier, EJ
Capetti, A
Macchetto, F
Sparks, WB
Ford, HJ
机构
[1] EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,DIV ASTROPHYS,2200 AG NOORDWIJK,NETHERLANDS
[2] JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218
关键词
dust; extinction; galaxies; individual; (NGC; 5128); jets; polarization;
D O I
10.1086/176917
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present imaging and polarimetry of NGC 5128 in the R and I bands obtained using the Hubble Space Telescope (HST) Wide Field Planetary Camera. The morphology and polarization properties of NGC 5128 at these wavelengths are dominated by the presence of the dust lane. The apparent V-band extinction ranges from 0.5 to 7 mag. The overall pattern of polarization is very regular, with the vectors oriented along the dust lane and with the degree of polarization proportional to extinction, consistent with the polarization being dominated by dichroic transmission through aligned dust grains in the foreground. After removing the effects of dust absorption, the nuclear region of the galaxy does not show a greatly perturbed morphology, and the resulting image looks qualitatively similar to those obtained from infrared observations. The location of the maximum of intrinsic emission, after correcting for extinction, is spatially coincident with the K-band peak as observed from the ground and also coincides with the maximum of obscuration and the highest polarization region. A compact, highly polarized emission knot seen at that location might be identified with a scattering cloud very close to the semiobscured nucleus af the galaxy. No optical synchrotron emission from the jet has been detected. This sets a lower limit to the radio-to-optical spectral index of similar to 0.55 which is consistent with the previous determinations of the spectral index for the synchrotron jet of Centaurus A.
引用
收藏
页码:535 / &
页数:20
相关论文
共 28 条
  • [1] ANTONUCCI RRJ, 1993, ARAA, V31, P477
  • [2] INFRARED POLARIMETRY OF THE NUCLEUS OF CENTAURUS-A - THE NEAREST BLAZAR
    BAILEY, J
    SPARKS, WB
    HOUGH, JH
    AXON, DJ
    [J]. NATURE, 1986, 322 (6075) : 150 - 151
  • [3] SPECTRAL EVOLUTION OF STELLAR POPULATIONS USING ISOCHRONE SYNTHESIS
    BRUZUAL, G
    CHARLOT, S
    [J]. ASTROPHYSICAL JOURNAL, 1993, 405 (02) : 538 - 553
  • [4] ROTATION AND INTERNAL MOTIONS IN NGC-5128
    BURBIDGE, EM
    BURBIDGE, GR
    [J]. ASTROPHYSICAL JOURNAL, 1959, 129 (02) : 271 - &
  • [5] THE INNER RADIO STRUCTURE OF CENTAURUS-A - CLUES TO THE ORIGIN OF THE JET X-RAY-EMISSION
    BURNS, JO
    FEIGELSON, ED
    SCHREIER, EJ
    [J]. ASTROPHYSICAL JOURNAL, 1983, 273 (01) : 128 - 153
  • [6] THE MORPHOLOGY OF THE NARROW-LINE REGION OF MARKARIAN-3
    CAPETTI, A
    MACCHETTO, F
    AXON, DJ
    SPARKS, WB
    BOKSENBERG, A
    [J]. ASTROPHYSICAL JOURNAL, 1995, 448 (02) : 600 - 610
  • [7] THE RELATIONSHIP BETWEEN INFRARED, OPTICAL, AND ULTRAVIOLET EXTINCTION
    CARDELLI, JA
    CLAYTON, GC
    MATHIS, JS
    [J]. ASTROPHYSICAL JOURNAL, 1989, 345 (01) : 245 - 256
  • [8] CLARKE DA, 1986, APJ, V300, P41
  • [9] PICTURE PROCESSING ANALYSIS OF THE OPTICAL STRUCTURE OF NGC 5128 (CENTAURUS-A)
    DUFOUR, RJ
    VANDENBERGH, S
    HARVEL, CA
    MARTINS, DH
    SCHIFFER, FH
    TALBOT, RJ
    TALENT, DL
    WELLS, DC
    [J]. ASTRONOMICAL JOURNAL, 1979, 84 (03) : 284 - 301
  • [10] Elvius A., 1964, Lowell Observatory Bulletin, V6, P123