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This paper presents surface photometry (B,V, I, J, H, K) and H_alpha rotation curves of 27 isolated spiral galaxies. The final goal is to obtain the mass distribution of a sample of isolated spiral galaxies in order to model their gas…

Astrophysics · Physics 2009-11-11 I. Perez , I. Marquez , K. Freeman , R. Fux

A simple algorithm is employed to deproject the two dimensional images of a pilot sample of 12 high-quality images of edge-on disk galaxies and to study their intrinsic 3 dimensional stellar distribution. We examine the radial profiles of…

Astrophysics · Physics 2008-11-26 M. Pohlen , S. Zaroubi , R. F. Peletier , R. -J. Dettmar

We present an extended morphometric system to automatically classify galaxies from astronomical images. The new system includes the original and modified versions of the CASGM coefficients (Concentration $C_1$, Asymmetry $A_3$, and…

Astrophysics of Galaxies · Physics 2015-09-21 Fabricio Ferrari , Reinaldo Ramos de Carvalho , Marina Trevisan

Recent observations have shown that most of the warps in the disk galaxies are asymmetric. However there exists no generic mechanism to generate these asymmetries in warps. We have shown that a rich variety of possible asymmetries in the…

Astrophysics · Physics 2015-06-24 K. Saha , C. J. Jog

Photometric deprojection is used to determine the stellardisk and bulge parameters for several edgeon galaxies from the FGC catalog. The assumption that the galaxies of our sample belonging to the fourth (i.e., lowest) surfacebrightness…

Astrophysics · Physics 2009-10-31 D. Bizyaev

When analyzing galaxy clustering in multi-band imaging surveys, there is a trade-off between selecting the largest galaxy samples (to minimize the shot noise) and selecting samples with the best photometric redshift (photo-z) precision,…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-07 Dimitrios Tanoglidis , Chihway Chang , Joshua Frieman

Spiral structure can contribute significantly to a galaxy's luminosity. However, only rarely are proper photometric models of spiral arms used in decompositions. As we show in the previous work, including the spirals as a separate component…

Large galaxies may contain an "atmosphere" of hot interstellar X-ray gas, and the temperature and radial density profile of this gas can be used to measure the total mass of the galaxy contained within a given radius r. We use this…

Astrophysics of Galaxies · Physics 2020-12-16 William E. Harris , Rhea-Silvia Remus , Gretchen L. H. Harris , Iurii V. Babyk

We use an automated galaxy morphology analysis method to quantitatively measure the spirality of galaxies classified manually as elliptical. The data set used for the analysis consists of 60,518 galaxy images with redshift obtained by the…

Astrophysics of Galaxies · Physics 2015-06-17 Levente Dojcsak , Lior Shamir

We quantify the mean asymmetry of 54 face-on, early type disk galaxies (S0 to Sab) using the amplitude of the m=1 azimuthal Fourier component of the R-band surface brightness. We find that the median lopsidedness, (A_1/A_0)_{mean}, of our…

Astrophysics · Physics 2009-10-30 Gregory Rudnick , Hans-Walter Rix

The warps in many spiral galaxies are now known to asymmetric. Recent sensitive observations have revealed that asymmetry of warps may be the norm rather than exception. However there exists no generic mechanism to generate these…

Astrophysics · Physics 2009-11-11 Kanak Saha , Chanda J. Jog

We study the optical morphology of galaxies in a large-scale hydrodynamic cosmological simulation, the EAGLE simulation. Galaxy morphologies were characterized using non-parametric statistics (Gini, $M_{20}$, Concentration and Asymmetry)…

Astrophysics of Galaxies · Physics 2020-01-08 Lucas A. Bignone , Susana E. Pedrosa , James W. Trayford , Patricia B. Tissera , Leonardo J. Pellizza

We created a catalog of photometric redshift of ~3,000,000 SDSS galaxies annotated by their broad morphology. The photometric redshift was optimized by testing and comparing several pattern recognition algorithms and variable selection…

Astrophysics of Galaxies · Physics 2018-06-12 Nicholas Paul , Nicholas Virag , Lior Shamir

We test the isotropy of the local distribution of galaxies using the 2MASS extended source catalogue. By decomposing the full sky survey into distinct patches and using a combination of photometric and spectroscopic redshift data, we use…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-29 Stephen Appleby , Arman Shafieloo

The disks of spiral galaxies are generally elliptical rather than circular. The distribution of ellipticities can be fit with a log-normal distribution. For a sample of 12,764 galaxies from the Sloan Digital Sky Survey Data Release 1 (SDSS…

Astrophysics · Physics 2009-11-10 Barbara S. Ryden

In the first paper of this series we use the publicly available code Gim2D to model the r- and i-band images of all galaxies in a magnitude-limited sample of roughly 1800 morphologically classified galaxies taken from the Sloan Digital Sky…

Astrophysics · Physics 2015-06-24 Lidia A. M. Tasca , Simon D. M. White

The opacity of a spiral disk due to dust absorption influences every measurement we make of it in the UV and optical. Two separate techniques directly measure the total absorption by dust in the disk: calibrated distant galaxy counts and…

Astrophysics · Physics 2008-01-21 B. W. Holwerda , R. A. Gonzalez , W. C. Keel , D. Calzetti , R. J. Allen , P. C. van de Kruit

Aims. We present the B-, V- and K-band surface photometry catalogs obtained running the automatic software GASPHOT on galaxies from the WINGS cluster survey having isophotal area larger than 200 pixels. The catalogs can be downloaded at the…

We present the MATLAB code Spirality, a novel method for measuring spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. Computation time is typically on the order of 2 minutes per galaxy, assuming at least 8…

As deeper observations discover increasingly distant galaxies, characterizing the properties of high-redshift galaxy populations will become increasingly challenging and paramount. We present a method for measuring the clustering bias of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Brant E. Robertson
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