相关论文: Extragalactic Thick Disks: Implications for Early …

We present the results of a detailed study of vertical surface brightness profiles of edge-on disk galaxies. Although the exponential disk scale height is constant to first order approximation, we show that for the large majority of…

The study of the Milky Way stellar discs in the context of galaxy formation is discussed. In particular we explore the properties of the Milky Way disc using a new sample of about 550 dwarf stars for which we have recently obtained…

The formation and evolution of galactic disks is particularly important for understanding how galaxies form and evolve, and the cause of the variety in which they appear to us. Ongoing large surveys, made possible by new instrumentation at…

The Galactic bulge, that is the prominent out-of-plane over-density present in the inner few kiloparsecs of the Galaxy, is a complex structure, as the morphology, kinematics, chemistry and ages of its stars indicate. To understand the…

We review the present knowledge of disk accretion in young low mass stars, and in particular, the mass accretion rate and its evolution with time. The methods used to obtain mass accretion rates from ultraviolet excesses and emission lines…

We examine a possible formation scenario of galactic thick discs with numerical simulations. Thick discs have previously been argued to form in clumpy disc phase in the high-redshift Universe, which host giant clumps of <10^9 M_sun in their…

Accurate characterization of thick disc properties from recent kinematic and photometric surveys provides converging evidences that this intermediate population is a sequel of the violent heating of early disc populations by a merging…

Building galaxy merger trees from a state-of-the-art cosmological hydrodynamics simulation, Horizon-AGN, we perform a statistical study of how mergers and smooth accretion drive galaxy morphologic properties above $z > 1$. More…

We study the distribution of orbital eccentricities of stars in thick disks generated by the heating of a pre-existing thin stellar disk through a minor merger (mass ratio 1:10), using N-body/SPH numerical simulations of interactions that…

Circumstellar disks are an integral part of the star formation process and the sites where planets are formed. Understanding the physical processes that drive their evolution, as disks evolve from optically thick to optically thin, is…

In this contribution, I present a simplified overview of the evolution of the disk galaxy population since z=1, and a brief discussion of a few open questions. Galaxy evolution surveys have found that the disk galaxy population forms stars…

There is now ample evidence that the interstellar thick disks of spiral galaxies are dusty. Although the majority of extraplanar gas in the first few kiloparsecs above the plane of a spiral galaxy is matter that has been expelled from the…

Circumbinary disks crucially affect the orbital and electromagnetic properties of binary systems across the universe, from stars in our galactic neighborhood to supermassive black hole binaries formed as the result of tumultuous galactic…

Stellar photometry obtained using the Hubble Space Telescope is used to study the distributions of the number densities of stars of various ages in 12 irregular and dwarf spiral galaxies viewed edge-on. Two subsystems can be distinguished…

We present a summary of our recent work on the vertical distribution of the resolved stellar populations in six low mass, edge-on, spiral galaxies observed with the Hubble Space Telescope Advanced Camera for Surveys (HST/ACS). In each…

We highlight some results from our detailed abundance analysis study of 703 kinematically selected F and G dwarf stars in the solar neighbourhood. The analysis is based on spectra of high-resolution (R=45000 to 110000) and high…

The behavior of the relative magnesium abundances in the thin-disk stars versus their orbital radii suggests that the star formation rate in the thin disk decreases with increasing Galactocentric distance, and there was no star formation…

We present kinematic measurements of thin and thick disk components in a sample of nine edge-on galaxies. We extract stellar and ionized gas rotation curves at and above the galaxies' midplanes using the Ca II triplet absorption features…

We perform controlled N-body simulations of disc galaxies growing within live dark matter (DM) haloes to present-day galaxies that contain both thin and thick discs. We consider two types of models: a) thick-disc initial conditions to which…

Newly formed stars are often observed to possess circumstellar disks, from which mass continues to be accreted onto the star and fed into outflowing jets, and which eventually may evolve into dusty debris disks and planetary systems. Recent…