High-frequency measurements of the spectrum of Sagittarius A*

被引:86
作者
Serabyn, E
Carlstrom, J
Lay, O
Lis, DC
Hunter, TR
Lacy, JH
Hills, RE
机构
[1] UNIV CHICAGO, DEPT ASTRON & ASTROPHYS, CHICAGO, IL 60637 USA
[2] NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA
[3] SMITHSONIAN ASTROPHYS OBSERV, CAMBRIDGE, MA 02138 USA
[4] UNIV TEXAS, AUSTIN, TX 78712 USA
[5] MULLARD RADIO ASTRON OBSERV, CAMBRIDGE CB3 OHE, ENGLAND
[6] CALTECH, PASADENA, CA 91125 USA
基金
美国国家科学基金会; 美国国家航空航天局;
关键词
galaxies; nuclei; galaxy; center;
D O I
10.1086/311010
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We report near-simultaneous interferometric measurements of the spectrum of Sagittarius A* over the 5-354 GHz range and single-dish observations that have yielded the first detection of Sgr A* at 850 GHz. We confirm that Sgr A*'s spectrum rises more steeply at short millimeter wavelengths than at centimeter wavelengths, leading to a near-millimeter/submillimeter excess that dominates its luminosity. Below 900 GHz, Sgr A*'s observed luminosity is 70 +/- 30 L.. A new upper limit to Sgr A*'s 24.3 mu m flux, together with a compilation of other extant IR data, imply a far-infrared spectral turnover, which can result from either an intrinsic synchrotron cutoff or excess extinction near Sgr A*. If the former applies, Sgr A*'s total synchrotron luminosity is <10(3) L., while in the latter case it is <3 x 10(4) L. if spherical symmetry also applies.
引用
收藏
页码:L77 / +
相关论文
共 29 条
  • [1] THE LUMINOSITY OF THE GALACTIC-CENTER
    DAVIDSON, JA
    WERNER, MW
    WU, X
    LESTER, DF
    HARVEY, PM
    JOY, M
    MORRIS, M
    [J]. ASTROPHYSICAL JOURNAL, 1992, 387 (01) : 189 - 211
  • [2] SUBMILLIMETER CONTINUUM EMISSION FROM THE GALACTIC-CENTER REGION
    DENT, WRF
    MATTHEWS, HE
    WADE, R
    DUNCAN, WD
    [J]. ASTROPHYSICAL JOURNAL, 1993, 410 (02) : 650 - 662
  • [3] DUSCHL WJ, 1994, ASTRON ASTROPHYS, V286, P431
  • [4] DUSCHL WJ, 1984, IAU S, V184
  • [5] HIGH ANGULAR RESOLUTION SPECTROSCOPIC AND POLARIMETRIC IMAGING OF THE GALACTIC-CENTER IN THE NEAR-INFRARED
    ECKART, A
    GENZEL, R
    HOFMANN, R
    SAMS, BJ
    TACCONIGARMAN, LE
    [J]. ASTROPHYSICAL JOURNAL, 1995, 445 (01) : L23 - L26
  • [6] FALCKE H, 1993, ASTRON ASTROPHYS, V270, P102
  • [7] FALCKE H, 1997, IAU S, V184
  • [8] FALCKE H, 1996, IAU S, V169, P169
  • [9] GENZEL R, 1997, IN PRESS MNRAS
  • [10] GEZARI D, 1994, NATO ADV SCI INST SE, V445, P427