skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: FORMING DOUBLE-BARRED GALAXIES FROM DYNAMICALLY COOL INNER DISKS

Abstract

About one-third of early-type barred galaxies host small-scale secondary bars. The formation and evolution of such double-barred (S2B) galaxies remain far from being well understood. In order to understand the formation of such systems, we explore a large parameter space of isolated pure-disk simulations. We show that a dynamically cool inner disk embedded in a hotter outer disk can naturally generate a steady secondary bar while the outer disk forms a large-scale primary bar. The independent bar instabilities of inner and outer disks result in long-lived double-barred structures whose dynamical properties are comparable to those in observations. This formation scenario indicates that the secondary bar might form from the general bar instability, the same as the primary bar. Under some circumstances, the interaction of the bars and the disk leads to the two bars aligning or single, nuclear, bars only. Simulations that are cool enough of the center to experience clump instabilities may also generate steady S2B galaxies. In this case, the secondary bars are “fast,” i.e., the bar length is close to the co-rotation radius. This is the first time that S2B galaxies containing a fast secondary bar are reported. Previous orbit-based studies had suggested that fast secondary barsmore » were not dynamically possible.« less

Authors:
;  [1];  [2]
  1. Key Laboratory of Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)
  2. Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE (United Kingdom)
Publication Date:
OSTI Identifier:
22522429
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 804; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; GALACTIC EVOLUTION; GALAXIES; INSTABILITY; ORBITS; ROTATION; SPACE

Citation Formats

Du, Min, Shen, Juntai, and Debattista, Victor P., E-mail: jshen@shao.ac.cn. FORMING DOUBLE-BARRED GALAXIES FROM DYNAMICALLY COOL INNER DISKS. United States: N. p., 2015. Web. doi:10.1088/0004-637X/804/2/139.
Du, Min, Shen, Juntai, & Debattista, Victor P., E-mail: jshen@shao.ac.cn. FORMING DOUBLE-BARRED GALAXIES FROM DYNAMICALLY COOL INNER DISKS. United States. doi:10.1088/0004-637X/804/2/139.
Du, Min, Shen, Juntai, and Debattista, Victor P., E-mail: jshen@shao.ac.cn. Sun . "FORMING DOUBLE-BARRED GALAXIES FROM DYNAMICALLY COOL INNER DISKS". United States. doi:10.1088/0004-637X/804/2/139.
@article{osti_22522429,
title = {FORMING DOUBLE-BARRED GALAXIES FROM DYNAMICALLY COOL INNER DISKS},
author = {Du, Min and Shen, Juntai and Debattista, Victor P., E-mail: jshen@shao.ac.cn},
abstractNote = {About one-third of early-type barred galaxies host small-scale secondary bars. The formation and evolution of such double-barred (S2B) galaxies remain far from being well understood. In order to understand the formation of such systems, we explore a large parameter space of isolated pure-disk simulations. We show that a dynamically cool inner disk embedded in a hotter outer disk can naturally generate a steady secondary bar while the outer disk forms a large-scale primary bar. The independent bar instabilities of inner and outer disks result in long-lived double-barred structures whose dynamical properties are comparable to those in observations. This formation scenario indicates that the secondary bar might form from the general bar instability, the same as the primary bar. Under some circumstances, the interaction of the bars and the disk leads to the two bars aligning or single, nuclear, bars only. Simulations that are cool enough of the center to experience clump instabilities may also generate steady S2B galaxies. In this case, the secondary bars are “fast,” i.e., the bar length is close to the co-rotation radius. This is the first time that S2B galaxies containing a fast secondary bar are reported. Previous orbit-based studies had suggested that fast secondary bars were not dynamically possible.},
doi = {10.1088/0004-637X/804/2/139},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 804,
place = {United States},
year = {2015},
month = {5}
}