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Related papers: What drives the variance of galaxy spectra?

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We analyse synthetic galaxy spectra from the evolutionary models of Bruzual&Charlot and Fioc&Rocca-Volmerange using the method of Principal Component Analysis (PCA). We explore synthetic spectra with different ages, star formation histories…

Astrophysics · Physics 2009-10-30 S. Ronen , A. Aragon-Salamanca , O. Lahav

Principal Component Analysis (PCA) is a well-known multivariate technique used to decorrelate a set of vectors. PCA has been extensively applied in the past to the classification of stellar and galaxy spectra. Here we apply PCA to the…

Astrophysics · Physics 2007-05-23 I. Ferreras , B. Rogers , O. Lahav , .

We analyse a sample of 26 active galactic nuclei with deep XMM-Newton observations, using principal component analysis (PCA) to find model independent spectra of the different variable components. In total, we identify at least 12…

High Energy Astrophysical Phenomena · Physics 2015-06-23 M. L. Parker , A. C. Fabian , G. Matt , K. I. I. Koljonen , E. Kara , W. Alston , D. J. Walton , A. Marinucci , L. Brenneman , G. Risaliti

We use Principal Component Analysis (PCA) to analyze a volume-limited sample from the SDSS and explore how cosmic web environments affect the interrelations between various galaxy properties, such as $(u-r)$ colour, stellar mass, specific…

Astrophysics of Galaxies · Physics 2025-06-24 Anindita Nandi , Biswajit Pandey

Principal Components Analysis (PCA) is a common way to study the sources of variation in a high-dimensional data set. Typically, the leading principal components are used to understand the variation in the data or to reduce the dimension of…

We use principal component analysis (PCA) to estimate stellar masses, mean stellar ages, star formation histories (SFHs), dust extinctions and stellar velocity dispersions for ~290,000 galaxies with stellar masses greater than $10^{11}Msun…

(Abridged) Motivated by forthcoming data from the Sloan Digital Sky Survey, we present a theoretical framework that can be used to interpret Principal Component Analysis (PCA) of disk galaxy properties. We use the formalism introduced by…

Astrophysics · Physics 2007-05-23 Alberto Conti , Barbara S. Ryden , David H. Weinberg

(Abridged) We apply Principal Component Analysis (PCA) to a sample of early-type galaxies from the Sloan Digital Sky Survey (SDSS) in order to infer differences in their star formation histories. Out of the first few principal components…

We apply Principal Component Analysis (PCA) to study the variability of the X-ray continuum in the Seyfert 1 galaxy NGC 7469. The PCA technique is used to separate out linear components contributing to variability between multiple datasets;…

Astrophysics · Physics 2007-05-23 A. J. Blustin , S. V. Fuerst , G. Branduardi-Raymont , M. J. Page , E. Behar , J. S. Kaastra

We apply Principal Component Analysis (PCA) to ~100,000 stellar spectra obtained by the Sloan Digital Sky Survey (SDSS). In order to avoid strong non-linear variation of spectra with effective temperature, the sample is binned into 0.02 mag…

Solar and Stellar Astrophysics · Physics 2010-02-15 Rosalie C. McGurk , Amy E. Kimball , Zeljko Ivezic

Principal Component Analysis (PCA) is applied to a variety of blazars to examine X-ray spectral variability. Data from nine different objects are analysed in two ways: long-term, which examines variability trends across years or decades,…

High Energy Astrophysical Phenomena · Physics 2018-08-08 Dennis Gallant , Luigi C. Gallo , Michael L. Parker

(Abridged) Environmental differences in the stellar populations of early-type galaxies are explored using principal component analysis (PCA), focusing on differences between elliptical galaxies in Hickson Compact Groups (HCGs) and in the…

Astrophysics · Physics 2009-11-11 I. Ferreras , A. Pasquali , R. R. de Carvalho , I. G. de la Rosa , O. Lahav

We have developed a web tool to perform Principal Component Analysis (PCA, Murtagh & Heck 1987; Kendall 1980) onto spectral data. The method is especially designed to perform spectral classification of galaxies from a sample of input…

Astrophysics of Galaxies · Physics 2009-09-22 Mauricio Ortiz , Gaspar Galaz

We analyse 400 ks of XMM-Newton data on the active galactic nucleus NGC 1365 using principal component analysis (PCA) to identify model independent spectral components. We find two significant components and demonstrate that they are…

High Energy Astrophysical Phenomena · Physics 2015-06-19 M. L. Parker , D. J. Walton , A. C. Fabian , G. Risaliti

We have investigated some statistical properties of integrated spectra of galaxies from Kennicutt (1992a) spectrophotometric atlas. The input for the analysis are galaxy spectra sampled in 1300 bins between 3750 \AA~ and 6500 \AA. We make…

Astrophysics · Physics 2015-06-24 Laerte Sodre , Hector Cuevas

Important but rare and subtle processes driving galaxy morphology and star-formation may be missed by traditional spiral, elliptical, irregular or S\'ersic bulge/disk classifications. To overcome this limitation, we use a principal…

We apply a principal component analysis (PCA) to the spectra of each of the 18 Seyfert 1-like objects observed more than 15 times by the international ultraviolet explorer (IUE) from 1978 until the end of 1991. PCA allows us to decompose…

Astrophysics · Physics 2007-05-23 Marc Turler , Thierry J. -L. Courvoisier

Here, we present a machine vision approach, combining a VAE framework with PCA, to decipher galaxy images. Using mock gri-band images from the EAGLE simulation, the VAE finds that around 35 features are needed to describe the images. Adding…

Astrophysics of Galaxies · Physics 2025-11-27 Samuel Howie , Ting-Yun Cheng , Carlton M. Baugh

We present the first principal component analysis (PCA) applied to a sample of 119 Spitzer Infrared Spectrograph (IRS) spectra of local ultraluminous infrared galaxies (ULIRGs) at z<0.35. The purpose of this study is to objectively and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Lingyu Wang , Duncan Farrah , Brian Connolly , Natalia Connolly , Vianney LeBouteiller , Seb Oliver , Henrik Spoon

The variability of active galactic nuclei (AGN) has long held the promise of shedding light on their detailed structure, and possibly other astrophysical phenonema. Different emission mechanisms lead to different patterns of variability in…

Astrophysics · Physics 2009-11-07 M. R. S. Hawkins
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