Access to Astronomical Catalogues

← Click to display the menu
J/ApJ/424/599       Abundances in  barred spiral galaxies (Martin+ 1994)

The influence of bars on the chemical composition of spiral galaxies Martin P., Roy J-R. <Astrophys. J. 424, 599 (1994)> =1994ApJ...424..599M (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Abundances Keywords: galaxies: abundances - galaxies: kinematics and dynamics - galaxies: structure - galaxies: spiral - H II regions Abstract: Imaging spectrophotometry in the nebular lines Hα, Hβ, [OIII]λ5007 and [NII]λ6584, using narrow-band interference filters, has been performed of 82, 55, and 79 H II regions in the barred spiral galaxies NGC 925, NGC 1073, and NGC 4303, respectively. The O/H abundance gradients were derived from the abundance indicators [O III]/Hβ and [N II]/[O III], calibrated by Edmunds & Pagel (1984MNRAS.211..507E). The global O/H gradients in NGC 925 [{DELTA}log(O/H)/{DELTA}R=0.033dex/kpc] and NGC 1073 [{DELTA}log(O/H)/{DELTA}R=0.048dex/kpc] are flatter than the gradients observed in normal galaxies of the same morphological type. The abundance gradient in NGC 4303 is identical to that found in normal spiral galaxies. A comparison is made between the O/H gradients of normal galaxies and of a sample of galaxies showing a barred morphology it is concluded that the global abundance gradients of spiral galaxies with a barred structure are in general shallower than gradients of normal galaxies. The slopes of O/H gradients are analyzed as a function of two properties of bars: the relative length of the bar with respect to the size of the disk, and the bar ellipticity, defined by the axis ratio of the bar. It is found that gradients are flatter when the length or the ellipticity of the bar increases. This result is consistent with recent models of radial flows. These observations indicate that large-scale mixing of the interstellar gas occurs across the disks of barred spiral galaxies and affects the radial distribution of elements. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 02 27.3 +33 35 NGC 925 02 43.7 +01 23 NGC 1073 12 21.9 +04 28 NGC 4303 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table5 55 82 Properties of H II regions in NGC 925 table6 55 55 Properties of H II regions in NGC 1073 table8 70 24 Properties of galaxies with abundance gradients with samples ≥10 H II regions
See also: VII/112 : RC2 Catalogue (de Vaucouleurs+ 1976) Byte-by-byte Description of file: table5 table6
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Region sequential number 4- 8 F5.2 --- log([OIII]/Hb) Corrected [O III]/Hβ line ratio 10- 13 F4.2 --- e_log([OIII]/Hb) rms uncertainty on log([OIII]/Hb) 15- 19 F5.2 --- log([NII]/[OIII]) ? Corrected [N II]/[O III] line ratio 21- 24 F4.2 --- e_log([NII]/[OIII]) ? rms uncertainty on log([NII]/[OIII]) 26- 30 F5.2 --- log([NII/Ha) ? Corrected [N II/Hα line ratio 32- 35 F4.2 --- e_log([NII/Ha) ? rms uncertainty on log([NII/Ha) 37- 40 F4.2 --- R/Reff Galactocentric distance corrected for inclination 42- 45 F4.2 --- c(Hb) Logarithmic extinction at Hβ 47- 50 F4.2 --- e_c(Hb) rms uncertainty on c(Hb) 52- 55 F4.2 --- O/H O/H gradient
Byte-by-byte Description of file: table8
Bytes Format Units Label Explanations
1- 8 A8 --- NGC Galaxy name 11- 19 A9 --- Type Morphological type 21- 22 I2 --- T T parameter (de Vaucouleurs et al., 1976, Cat. VII/112) 24- 25 I2 deg i Inclination angle 27- 29 I3 deg PA [-30/170] Position angle 31- 34 F4.1 Mpc Dist Distance 36- 38 I3 --- N Number of H II regions used to derive the O/H gradient 40- 42 I3 arcsec Rad25 ? Radius at the 25 magnitude/arcsec2 isophote in blue light 44- 46 I3 arcsec a ? Semi-major axis 48- 49 I2 arcsec b ? Semi-minor axis 52 I1 --- Ebar ? Bar ellipticity (Ebar=10(1-b/a)) 54- 57 F4.2 --- a/Rad25 ? a/Rad25 ratio 59- 64 F6.3 kpc-1 Slope Slope of the global O/H gradient normalized for the adopted distance 66- 67 I2 --- r_PA References for inclination & position angle (1) 69- 70 I2 --- r_N References for N and slopes of gradients (1)
Note (1): References : 1: Vila-Costas & Edmunds 1992MNRAS.259..121V 2: Belley & Roy 1992ApJS...78...61B 3: Wevers et al. 1986A&AS...66..505W 4: Our study 5: England, Gottesman, & Hunter 1990ApJ...348..456E 6: Roy et al. 1996ApJ...460..284R 7: Walsh & Roy 1989ApJ...341..722W 8: Martin 1992, Ph.D. thesis, Univ. d'Aix-Marseille I 9: Oey & Kennicutt 1993ApJ...411..137O 10: Martin et al. 1989ApJ...345..707M 11: Warmels 1988A&AS...72...57W 12: Martin & Roy 1992ApJ...397..463M 13: Scowen, Dufour & Hester 1992AJ....104...92S 14: Zaritsky et al. 1994ApJ...420...87Z
History: Prepared via OCR at CDS.
(End) James Marcout, Patricia Bauer [CDS] 21-Mar-1997
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© UDS/CNRS

Contact