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

Title: An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies

Abstract

The development of two-dimensional (2D) bulge-to-disk decomposition techniques has shown their advantages over traditional one-dimensional (1D) techniques, especially for galaxies with non-axisymmetric features. However, the full potential of 2D techniques has yet to be fully exploited. Secondary morphological features in nearby disk galaxies, such as bars, lenses, rings, disk breaks, and spiral arms, are seldom accounted for in 2D image decompositions, even though some image-fitting codes, such as GALFIT, are capable of handling them. We present detailed, 2D multi-model and multi-component decomposition of high-quality R -band images of a representative sample of nearby disk galaxies selected from the Carnegie-Irvine Galaxy Survey, using the latest version of GALFIT. The sample consists of five barred and five unbarred galaxies, spanning Hubble types from S0 to Sc. Traditional 1D decomposition is also presented for comparison. In detailed case studies of the 10 galaxies, we successfully model the secondary morphological features. Through a comparison of best-fit parameters obtained from different input surface brightness models, we identify morphological features that significantly impact bulge measurements. We show that nuclear and inner lenses/rings and disk breaks must be properly taken into account to obtain accurate bulge parameters, whereas outer lenses/rings and spiral arms have a negligible effect.more » We provide an optimal strategy to measure bulge parameters of typical disk galaxies, as well as prescriptions to estimate realistic uncertainties of them, which will benefit subsequent decomposition of a larger galaxy sample.« less

Authors:
 [1];  [2]
  1. Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China)
  2. Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)
Publication Date:
OSTI Identifier:
22663235
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 845; 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; AXIAL SYMMETRY; BRIGHTNESS; DECOMPOSITION; GALAXIES; ONE-DIMENSIONAL CALCULATIONS; PHOTOMETRY; SIMULATION; SURFACES; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Gao Hua, and Ho, Luis C. An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7DA4.
Gao Hua, & Ho, Luis C. An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies. United States. doi:10.3847/1538-4357/AA7DA4.
Gao Hua, and Ho, Luis C. Sun . "An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies". United States. doi:10.3847/1538-4357/AA7DA4.
@article{osti_22663235,
title = {An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies},
author = {Gao Hua and Ho, Luis C.},
abstractNote = {The development of two-dimensional (2D) bulge-to-disk decomposition techniques has shown their advantages over traditional one-dimensional (1D) techniques, especially for galaxies with non-axisymmetric features. However, the full potential of 2D techniques has yet to be fully exploited. Secondary morphological features in nearby disk galaxies, such as bars, lenses, rings, disk breaks, and spiral arms, are seldom accounted for in 2D image decompositions, even though some image-fitting codes, such as GALFIT, are capable of handling them. We present detailed, 2D multi-model and multi-component decomposition of high-quality R -band images of a representative sample of nearby disk galaxies selected from the Carnegie-Irvine Galaxy Survey, using the latest version of GALFIT. The sample consists of five barred and five unbarred galaxies, spanning Hubble types from S0 to Sc. Traditional 1D decomposition is also presented for comparison. In detailed case studies of the 10 galaxies, we successfully model the secondary morphological features. Through a comparison of best-fit parameters obtained from different input surface brightness models, we identify morphological features that significantly impact bulge measurements. We show that nuclear and inner lenses/rings and disk breaks must be properly taken into account to obtain accurate bulge parameters, whereas outer lenses/rings and spiral arms have a negligible effect. We provide an optimal strategy to measure bulge parameters of typical disk galaxies, as well as prescriptions to estimate realistic uncertainties of them, which will benefit subsequent decomposition of a larger galaxy sample.},
doi = {10.3847/1538-4357/AA7DA4},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 845,
place = {United States},
year = {2017},
month = {8}
}