TY - JOUR

T1 - Pitch angle variations in spiral galaxies

AU - Savchenko, S.S.

AU - Reshetnikov, V.P.

PY - 2013

Y1 - 2013

N2 - We present a detailed photometric study and measurements of spiral arm pitch angles for a sample of 50 non-barred or weakly barred grand-design spiral galaxies selected from Sloan Digital Sky Survey. In order to find pitch angles, we used a new method based on the window Fourier analysis of their images. This method allows us not only to infer the average pitch angle, but to obtain its value as a function of galactocentric radius as well. Our main results are as follows: (1) Spiral arms of most galaxies cannot be described by a single value of the pitch angle. About 2/3 of galaxies demonstrate pitch angle variations exceeding 20 per cent. In most galaxies in the sample their pitch angle decreases by increasing the distance from the centre. (2) Pitch angle variations correlate with the properties of galaxies - with the shape of the surface brightness distribution (envelope-type or truncated disc), and with the sign of stellar disc colour gradient. (3) More luminous and bright bulges produce more tightly wound

AB - We present a detailed photometric study and measurements of spiral arm pitch angles for a sample of 50 non-barred or weakly barred grand-design spiral galaxies selected from Sloan Digital Sky Survey. In order to find pitch angles, we used a new method based on the window Fourier analysis of their images. This method allows us not only to infer the average pitch angle, but to obtain its value as a function of galactocentric radius as well. Our main results are as follows: (1) Spiral arms of most galaxies cannot be described by a single value of the pitch angle. About 2/3 of galaxies demonstrate pitch angle variations exceeding 20 per cent. In most galaxies in the sample their pitch angle decreases by increasing the distance from the centre. (2) Pitch angle variations correlate with the properties of galaxies - with the shape of the surface brightness distribution (envelope-type or truncated disc), and with the sign of stellar disc colour gradient. (3) More luminous and bright bulges produce more tightly wound

KW - methods: data analysis

KW - galaxies: photometry

KW - galaxies: structure

U2 - 10.1093/mnras/stt1627

DO - 10.1093/mnras/stt1627

M3 - Article

VL - 436

SP - 1074

EP - 1083

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 2

ER -