Disk and spheroidal components of external galaxies: an overview

Secular Evolution in Disk Galaxies: Pseudobulge Growth and the Formation of Spheroidal Galaxies

Updating Kormendy & Kennicutt (2004, ARA&A, 42, 603), we review internal secular evolution of galaxy disks. One consequence is the growth of pseudobulges that often are mistaken for true (merger-built) bulges. Many pseudobulges are recognizable as cold, rapidly rotating, disky structures. Bulges have Sérsic function brightness profiles with index n > ∼ 2 while most pseudobulges have n < ∼ 2. Re...

Dwarf Spheroidal Galaxies

Bending instability in galaxies: the stellar disk thickness and the mass of spheroidal component

We present results of numerical N-body simulations of a galactic stellar disk embedded into a spherical dark halo. The non-linear dynamics of bending instabilities developing in the disk is studied. The bending modes, axisymmetric and not, are considered as main factors increasing the disk thickness. The relation between the disk vertical scale height and the halo+bulge-to-disk mass ratio is in...

effect of seed priming and irrigation regimes on yield,yield components and quality of safflowers cultivars

این مطالعه در سال 1386-87 در آزمایشگاه و مزرعه پژوهشی دانشگاه صنعتی اصفهان به منظور تعیین مناسب ترین تیمار بذری و ارزیابی اثر پرایمینگ بر روی سه رقم گلرنگ تحت سه رژیم آبیاری انجام گرفت. برخی از مطالعات اثرات سودمند پرایمینگ بذر را بر روی گیاهان مختلف بررسی کرده اند اما در حال حاضر اطلاعات کمی در مورد خصوصیات مربوط به جوانه زنی، مراحل نموی، عملکرد و خصوصیات کمی و کیفی بذور تیمار شده ژنوتیپ های م...

Life and times of dwarf spheroidal galaxies

We propose a cosmological scenario for the formation and evolution of dwarf spheroidal galaxies (dSphs), satellites of the Milky Way (MW). An improved version of the semi-analytical code GAMETE (GAlaxy Merger Tree & Evolution) is used to follow the dSphs evolution simultaneously with the MW formation, matching the observed properties of both. In this scenario dSph galaxies represent fossil obje...