Inversion of stellar statistics equation for the Galactic Bulge
arXiv:astro-ph/9911182 · doi:10.1046/j.1365-8711.2000.03220.x
Abstract
A method based on Lucy (1974, AJ 79, 745) iterative algorithm is developed to invert the equation of stellar statistics for the Galactic bulge and is then applied to the K-band star counts from the Two-Micron Galactic Survey in a number of off-plane regions (10 deg.>|b|>2 deg., |l|<15 deg.). The top end of the K-band luminosity function is derived and the morphology of the stellar density function is fitted to triaxial ellipsoids, assuming a non-variable luminosity function within the bulge. The results, which have already been outlined by Lopez-Corredoira et al.(1997, MNRAS 292, L15), are shown in this paper with a full explanation of the steps of the inversion: the luminosity function shows a sharp decrease brighter than M_K=-8.0 mag when compared with the disc population; the bulge fits triaxial ellipsoids with the major axis in the Galactic plane at an angle with the line of sight to the Galactic centre of 12 deg. in the first quadrant; the axial ratios are 1:0.54:0.33, and the distance of the Sun from the centre of the triaxial ellipsoid is 7860 pc. The major-minor axial ratio of the ellipsoids is found not to be constant. However, the interpretation of this is controversial. An eccentricity of the true density-ellipsoid gradient and a population gradient are two possible explanations. The best fit for the stellar density, for 1300 pc<t<3000 pc, are calculated for both cases, assuming an ellipsoidal distribution with constant axial ratios, and when K_z is allowed to vary. From these, the total number of bulge stars is ~ 3 10^{10} or ~ 4 10^{10}, respectively.
19 pages, 23 figures, accepted in MNRAS
References in corpus (2)
Cited by in corpus (33)
- Mapping the Three-Dimensional Density of the Galactic Bulge with VVV Red Clump Stars
- Old stellar Galactic disc in near-plane regions according to 2MASS: scales, cut-off, flare and warp
- Spiral arms, bar shape and bulge microlensing in the Milky Way
- Stellar populations in the Milky Way bulge region : Towards solving the Galactic bulge and bar shapes using 2MASS data
- Gas flow models in the Milky Way embedded bars
- Modelling the Galactic bar using OGLE-II Red Clump Giant Stars
- Detection of the old stellar component of the major Galactic bar
- Do most planetary nebulae derive from binaries? I Population synthesis model of the galactic planetary nebula population produced by singlestars and binaries
- Constraints on the Galactic Bar from the Hercules stream as traced with RAVE across the Galaxy
- Tracing the long bar with red-clump giants
- The Long Bar in the Milky Way. Corroboration of an old hypothesis
- The long Galactic bar as seen by UKIDSS Galactic Plane Survey
- A boxy bulge in the Milky Way. Inversion of the stellar statistics equation with 2MASS data
- Strong Evidence that the Galactic Bulge is Shining in Gamma Rays
- Generation of galactic disc warps due to intergalactic accretion flows onto the disc
- A parametric description of the 3D structure of the Galactic Bar/Bulge using the VVV survey
- 3D outer bulge structure from near infrared star counts
- Searching for the in-plane Galactic bar and ring in DENIS
- The 3D structure of the Galactic bulge
- Chemical Abundances and Dust in Planetary Nebulae in the Galactic Bulge
- Gaia-DR2 extended kinematical maps. Part I: Method and application
- A Galaxy Model from 2MASS Star Counts in the Whole Sky Including the Plane
- Evidence for a deficit of young and old stars in the Milky Way inner in-plane disc
- Stellar density distribution in the NIR on the Galactic plane at longitudes 15-27 deg. Clues for the Galactic bar ?
- Mass distribution in our Galaxy
- Structure of the outer Galactic disc with Gaia-DR2
- Inverse Compton emission from millisecond pulsars in the Galactic bulge
- FEDReD I: 3D extinction and stellar maps by Bayesian deconvolution
- The intrinsic shape of galaxy bulges
- Understanding the velocity distribution of the Galactic Bulge with APOGEE and Gaia
- Non-Parametric Density Reconstruction of the Galactic Bulge Area using Red Clump Stars in the VVV Survey
- An excess of very bright stars in the inner bulge
- The bulge luminosity functions in the MSX infrared bands