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Related papers: An inner ring and the micro lensing toward the Bul…

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The measurements of the possible gravitational microlensing events are analysed with a simple yet accurate disc--halo model of the Milky Way Galaxy. This comprises a luminous exponential disc embedded in a flattened dark matter halo with…

Astrophysics · Physics 2016-06-08 N. W. Evans , J. Jijina

We show that current microlensing and dynamical observations of the Galaxy permit to set interesting constraints on the Dark Matter local density and profile slope towards the galactic centre. Assuming state-of-the-art models for the…

Astrophysics of Galaxies · Physics 2011-11-18 Fabio Iocco , Miguel Pato , Gianfranco Bertone , Philippe Jetzer

We present results of a high-resolution imaging survey of barred S0--Sa galaxies which demonstrate that the central regions of these galaxies are surprisingly complex. We see many inner bars --- small, secondary bars (typically less than a…

Astrophysics · Physics 2007-05-23 Peter Erwin , Linda S. Sparke , Juan Carlos Vega Beltran , John Beckman

Galactic bulge microlensing surveys provide a probe of Galactic structure. We present the first field-by-field comparison between microlensing observations and the Besan\c{c}on population synthesis Galactic model. Using an updated version…

Earth and Planetary Astrophysics · Physics 2016-01-27 Supachai Awiphan , Eamonn Kerins , Annie Robin

Using a volume- and mass-limited (D < 30 Mpc, log (M_star/M_sun) $\geq 9.75$) sample of 155 barred S0-Sd galaxies, I determine the fraction with secondary structures within their bars. Some 20 +/- 3% have a separate inner bar, making them…

Astrophysics of Galaxies · Physics 2023-12-21 Peter Erwin

We analyse the secular effects of a long-lived Galactic spiral structure on the stellar orbits with mean radii close to the corotation resonance. By test-particle simulations and different spiral potential models with parameters constrained…

Astrophysics of Galaxies · Physics 2015-06-16 Douglas A. Barros , Jacques R. D. Lépine , Thiago C. Junqueira

We study different models of dark matter distribution for the halo of our galaxy. In particular, we consider Eddington and King-Michie models, which [C[C, which include anisotropy in the velocity space, and compute in a self-consistent way…

Astrophysics · Physics 2009-10-28 F. De Paolis , G. Ingrosso , Ph. Jetzer

The bulge is a region of the Galaxy which is of tremendous interest for understanding Galaxy formation. However, measuring photometry and kinematics in it raises several inherent issues, like high extinction in the visible and severe…

Astrophysics · Physics 2009-11-10 A. C. Robin , C. Reylé , S. Picaud , M. Schultheis

The gravitational microlensing as a unique astrophysical tool can be used for studying the atmosphere of stars thousands of parsec far from us. This capability results from the bending of light rays in the gravitational field of a lens…

Solar and Stellar Astrophysics · Physics 2015-08-06 Sedighe Sajadian , Sohrab Rahvar

The optical depth to microlensing toward M31 due to known stars in the disk of M31 itself is $\tau\sim 2\times 10^{-7}e^{-r/d}$ where $d$ is the disk scale length and $r$ is the distance along the major axis. Thus, there can be significant…

Astrophysics · Physics 2009-10-22 Andrew Gould

The results of bar-driven mass inflow are directly observable in high-resolution HST observations of their circumnuclear regions. These observations reveal a wealth of structures dominated by dust lanes, often with a spiral-like morphology,…

Astrophysics · Physics 2016-01-27 Paul Martini

A list of galaxies with inner regions revealing polar (or strongly inclined to the main galactic plane) disks and rings is compiled from the literature data. The list contains 47 galaxies of all morphological types, from E to Irr. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 A. V. Moiseev

The color-magnitude diagram of $ \sim 3 \times 10^5 $ stars obtained for Baade's Window towards the Galactic bulge with the OGLE project reveals a surprisingly narrow main sequence due to galactic disk stars at a distance of $d \sim 2 $…

Astrophysics · Physics 2009-10-22 B. Paczynski , K. Z. Stanek , A. Udalski , M. Szymanski , J. Kaluzny , M. Kubiak , M. Mateo

The spectroscopy of microlensed sources towards the Galactic bulge provides a unique opportunity to study (i) the kinematics of the Galactic bulge, particularly its far-side, (ii) the effects of extinction on the microlensed sources, and…

Astrophysics · Physics 2009-11-06 Stephen R. Kane , Kailash C. Sahu

Microlensing campaigns have a long history of observations covering the Galactic bulge, where thousands of detections have been obtained, including many exoplanetary systems. The Euclid Galactic Bulge Survey represents a unique opportunity…

We propose a near-infrared microlensing survey of the central 2 degree field of the Galactic Center, in an attempt to estimate the surface density and mass distribution of distant free-floating brown dwarfs in the bulge and in the disk,…

Astrophysics · Physics 2016-08-30 Hans Zinnecker

Inner bars are frequent structures in the local Universe and thought to substantially influence the nuclear regions of disc galaxies. In this study we explore the structure and dynamics of inner bars by deriving maps and radial profiles of…

The most important uncertainty in the results of gravitational microlensing experiments comes from the difficulties of photometry caused by blending of source stars. Recently Nemiroff (1997) pointed out that the results of microlensing…

Astrophysics · Physics 2007-05-23 Seunghun Lee , Cheongho Han

We use N-body simulations of bar formation in isolated galaxies to study the effect of bulge mass and bulge concentration on bar formation. Bars are global disk instabilities that evolve by transferring angular momentum from the inner to…

Astrophysics of Galaxies · Physics 2018-01-03 Sandeep Kumar Kataria , Mousumi Das

We examine the possibility of observing gravitational lensing in the weak deflection regime by the supermassive black hole in the center of the galaxy M31. This black hole is significantly more massive than the black hole in the center of…

Astrophysics · Physics 2009-06-23 V. Bozza , S. Calchi Novati , L. Mancini