The photometric structure of the inner Galaxy

@article{citeulike:2361527, abstract = {The light distribution in the inner few kiloparsecs of the Milky Way is recovered non-parametrically from a dust-corrected near-infrared COBE/DIRBE surface brightness map of the inner Galaxy. The best fits to the photometry are obtained when the Sun is assumed to lie ~14+/-4pc above the plane. The recovered density distributions clearly show an elongated three-dimensional bulge set in a highly non-axisymmetric disc. In the favoured models, the bulge has axis ratios 1:0.6:0.4 and semi-major axis length ~2kpc. Its nearer long axis lies in the first quadrant. The bulge is surrounded by an elliptical disc that extends to ~2kpc on the minor axis and ~3.5kpc on the major axis. In all models there is a local density minimum ~2.2kpc down the minor axis. The subsequent maximum ~3kpc down the minor axis (corresponding to l~=-22 deg and l~=17 deg) may be associated with the Lagrange point L\_4. From this identification and the length of the bulge-bar, we infer a pattern speed Omega\_b~=60-70^-1kms kpc^-1 for the bar. Experiments in which pseudo-data derived from models with spiral structure were deprojected under the assumption that the Galaxy is either eight-fold or four-fold symmetric indicate that the highly non-axisymmetric discs recovered from the COBE data could reflect spiral structure within the Milky Way if that structure involves density contrasts greater than \>~3 at near-infrared wavelengths. These experiments indicate that the angle phi\_0 between the Sun-centre line and a major axis of the bulge lies near 20 deg.}, author = {Binney, J. and Gerhard, O. and Spergel, D. }, citeulike-article-id = {2361527}, eprint = {astro-ph/9609066}, journal = {Mon. Not. Roy. Astron. Soc.}, keywords = {bjs, galaxy}, month = {June}, pages = {365--374}, posted-at = {2008-02-11 06:53:31}, priority = {2}, title = {The photometric structure of the inner Galaxy}, url = {http://arxiv.org/abs/astro-ph/9609066}, volume = {288}, year = {1997} }

TY - JOUR ID - citeulike:2361527 L3 - citeulike-article-id:2361527 TI - The photometric structure of the inner Galaxy JF - Mon. Not. Roy. Astron. Soc. VL - 288 SP - 365 EP - 374 N2 - The light distribution in the inner few kiloparsecs of the Milky Way is recovered non-parametrically from a dust-corrected near-infrared COBE/DIRBE surface brightness map of the inner Galaxy. The best fits to the photometry are obtained when the Sun is assumed to lie ~14+/-4pc above the plane. The recovered density distributions clearly show an elongated three-dimensional bulge set in a highly non-axisymmetric disc. In the favoured models, the bulge has axis ratios 1:0.6:0.4 and semi-major axis length ~2kpc. Its nearer long axis lies in the first quadrant. The bulge is surrounded by an elliptical disc that extends to ~2kpc on the minor axis and ~3.5kpc on the major axis. In all models there is a local density minimum ~2.2kpc down the minor axis. The subsequent maximum ~3kpc down the minor axis (corresponding to l~=-22 deg and l~=17 deg) may be associated with the Lagrange point L_4. From this identification and the length of the bulge-bar, we infer a pattern speed Omega_b~=60-70^-1kms kpc^-1 for the bar. Experiments in which pseudo-data derived from models with spiral structure were deprojected under the assumption that the Galaxy is either eight-fold or four-fold symmetric indicate that the highly non-axisymmetric discs recovered from the COBE data could reflect spiral structure within the Milky Way if that structure involves density contrasts greater than >~3 at near-infrared wavelengths. These experiments indicate that the angle phi_0 between the Sun-centre line and a major axis of the bulge lies near 20 deg. KW - bjs KW - galaxy AU - Binney, J AU - Gerhard, O AU - Spergel, D PY - 1997/June// UR - http://arxiv.org/abs/astro-ph/9609066 ER -