Another bar in the Bulge

被引:72
作者
Alard, C
机构
[1] Inst Astrophys, F-75014 Paris, France
[2] Observ Paris, F-75014 Paris, France
关键词
Galaxy : bulge; Galaxy : structure;
D O I
10.1051/0004-6361:20011487
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
A map of the projected density of the old stellar population of the Galactic Bulge region is reconstructed using 2MASS data. By making a combination of the H and K photometric bands, it is possible to overcome the effect of reddening, and thus penetrate the inner structure of the Galactic Bulge. The main structure in the map corresponds to the well documented peanut shaped bar which is formed by the inner parts of the Galactic disk as a result of dynamical instabilities. As suggested by numerical simulations, the projected Z profile of the bar, has an almost exponential shape. After subtracting the exponential profile associated with the bar, a large residual appear near the Galactic Center. This residual is elongated and asymmetrical, which suggest a bar structure. Thus we arrive at the conclusion that in addition to the main bar a smaller bar with a different orientation may exist in the central region of the Milky Way. This finding makes the Milky Way very similar to a large number of barred spiral Galaxies which show as well a smaller bar in their central regions.
引用
收藏
页码:L44 / L47
页数:4
相关论文
共 20 条
  • [1] UNDERSTANDING THE KINEMATICS OF GALACTIC-CENTER GAS
    BINNEY, J
    GERHARD, OE
    STARK, AA
    BALLY, J
    UCHIDA, KI
    [J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1991, 252 (02) : 210 - 218
  • [2] DIRECT EVIDENCE FOR A BAR AT THE GALACTIC-CENTER
    BLITZ, L
    SPERGEL, DN
    [J]. ASTROPHYSICAL JOURNAL, 1991, 379 (02) : 631 - 638
  • [3] THE RELATIONSHIP BETWEEN INFRARED, OPTICAL, AND ULTRAVIOLET EXTINCTION
    CARDELLI, JA
    CLAYTON, GC
    MATHIS, JS
    [J]. ASTROPHYSICAL JOURNAL, 1989, 345 (01) : 245 - 256
  • [4] Hubble Space Telescope optical-near-infrared colors of nearby R1/4 and exponential bulges
    Carollo, CM
    Stiavelli, M
    de Zeeuw, PT
    Seigar, M
    Dejonghe, H
    [J]. ASTROPHYSICAL JOURNAL, 2001, 546 (01) : 216 - 222
  • [5] COMBES F, 1990, ASTRON ASTROPHYS, V233, P82
  • [6] MORPHOLOGY, NEAR-INFRARED LUMINOSITY, AND MASS OF THE GALACTIC BULGE FROM COBE DIRBE OBSERVATIONS
    DWEK, E
    ARENDT, RG
    HAUSER, MG
    KELSALL, T
    LISSE, CM
    MOSELEY, SH
    SILVERBERG, RF
    SODROSKI, TJ
    WEILAND, JL
    [J]. ASTROPHYSICAL JOURNAL, 1995, 445 (02) : 716 - 730
  • [7] Triple bars and complex central structures in disk galaxies
    Erwin, P
    Sparke, LS
    [J]. ASTROPHYSICAL JOURNAL, 1999, 521 (01) : L37 - L40
  • [8] Disc galaxies with multiple triaxial structures .2. JHK surface photometry and numerical simulations
    Friedli, D
    Wozniak, H
    Rieke, M
    Martinet, L
    Bratschi, P
    [J]. ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 1996, 118 (03): : 461 - 479
  • [9] Friedli D, 1996, ASTRON ASTROPHYS, V312, P761
  • [10] Searching for the in-plane Galactic bar and ring in DENIS
    López-Corredoira, M
    Hammersley, PL
    Garzón, F
    Cabrera-Lavers, A
    Castro-Rodríguez, N
    Schultheis, M
    Mahoney, TJ
    [J]. ASTRONOMY & ASTROPHYSICS, 2001, 373 (01): : 139 - 152