U.S. Department of EnergyOffice of Scientific and Technical Information
Objective identification of informative wavelength regions in galaxy spectra
Abstract
Understanding the diversity in spectra is the key to determining the physical parameters of galaxies. The optical spectra of galaxies are highly convoluted with continuum and lines that are potentially sensitive to different physical parameters. Defining the wavelength regions of interest is therefore an important question. In this work, we identify informative wavelength regions in a single-burst stellar population model using the CUR Matrix Decomposition. Simulating the Lick/IDS spectrograph configuration, we recover the widely used D {sub n}(4000), Hβ, and Hδ {sub A} to be most informative. Simulating the Sloan Digital Sky Survey spectrograph configuration with a wavelength range 3450-8350 Å and a model-limited spectral resolution of 3 Å, the most informative regions are: first region—the 4000 Å break and the Hδ line; second region—the Fe-like indices; third region—the Hβ line; and fourth region—the G band and the Hγ line. A principal component analysis on the first region shows that the first eigenspectrum tells primarily the stellar age, the second eigenspectrum is related to the age-metallicity degeneracy, and the third eigenspectrum shows an anti-correlation between the strengths of the Balmer and the Ca K and H absorptions. The regions can be used to determine the stellar age and metallicity inmore »
- Authors:
-
- Department of Physics and Astronomy, The Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218 (United States)
- Department of Mathematics, Stanford University, Stanford, CA 94305 (United States)
- Department of Physics of Complex Systems, Eötvös Loránd University, H-1117 Budapest (Hungary)
- Publication Date:
- OSTI Identifier:
- 22340259
- Resource Type:
- Journal Article
- Journal Name:
- Astronomical Journal (New York, N.Y. Online)
- Additional Journal Information:
- Journal Volume: 147; Journal Issue: 5; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; ABUNDANCE; COMPUTERIZED SIMULATION; CONFIGURATION; CORRELATIONS; DATA ANALYSIS; DECOMPOSITION; DUSTS; GALAXIES; METALLICITY; RESOLUTION; SPECTRA; SPECTROSCOPY; STARS; WAVELENGTHS
Citation Formats
Yip, Ching-Wa, Szalay, Alexander S., Budavári, Tamás, Wyse, Rosemary F. G., Mahoney, Michael W., Csabai, István, and Dobos, Laszlo. Objective identification of informative wavelength regions in galaxy spectra. United States: N. p., 2014.
Web. doi:10.1088/0004-6256/147/5/110.
Yip, Ching-Wa, Szalay, Alexander S., Budavári, Tamás, Wyse, Rosemary F. G., Mahoney, Michael W., Csabai, István, & Dobos, Laszlo. Objective identification of informative wavelength regions in galaxy spectra. United States. https://doi.org/10.1088/0004-6256/147/5/110
Yip, Ching-Wa, Szalay, Alexander S., Budavári, Tamás, Wyse, Rosemary F. G., Mahoney, Michael W., Csabai, István, and Dobos, Laszlo. 2014.
"Objective identification of informative wavelength regions in galaxy spectra". United States. https://doi.org/10.1088/0004-6256/147/5/110.
@article{osti_22340259,
title = {Objective identification of informative wavelength regions in galaxy spectra},
author = {Yip, Ching-Wa and Szalay, Alexander S. and Budavári, Tamás and Wyse, Rosemary F. G. and Mahoney, Michael W. and Csabai, István and Dobos, Laszlo},
abstractNote = {Understanding the diversity in spectra is the key to determining the physical parameters of galaxies. The optical spectra of galaxies are highly convoluted with continuum and lines that are potentially sensitive to different physical parameters. Defining the wavelength regions of interest is therefore an important question. In this work, we identify informative wavelength regions in a single-burst stellar population model using the CUR Matrix Decomposition. Simulating the Lick/IDS spectrograph configuration, we recover the widely used D {sub n}(4000), Hβ, and Hδ {sub A} to be most informative. Simulating the Sloan Digital Sky Survey spectrograph configuration with a wavelength range 3450-8350 Å and a model-limited spectral resolution of 3 Å, the most informative regions are: first region—the 4000 Å break and the Hδ line; second region—the Fe-like indices; third region—the Hβ line; and fourth region—the G band and the Hγ line. A principal component analysis on the first region shows that the first eigenspectrum tells primarily the stellar age, the second eigenspectrum is related to the age-metallicity degeneracy, and the third eigenspectrum shows an anti-correlation between the strengths of the Balmer and the Ca K and H absorptions. The regions can be used to determine the stellar age and metallicity in early-type galaxies that have solar abundance ratios, no dust, and a single-burst star formation history. The region identification method can be applied to any set of spectra of the user's interest, so that we eliminate the need for a common, fixed-resolution index system. We discuss future directions in extending the current analysis to late-type galaxies. ASCII formatted tables of the regional eigenspectra are available.},
doi = {10.1088/0004-6256/147/5/110},
url = {https://www.osti.gov/biblio/22340259},
journal = {Astronomical Journal (New York, N.Y. Online)},
issn = {1538-3881},
number = 5,
volume = 147,
place = {United States},
year = {Thu May 01 00:00:00 EDT 2014},
month = {Thu May 01 00:00:00 EDT 2014}
}
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