Access to Astronomical Catalogues

← Click to display the menu
J/ApJ/655/851       Wolf-Rayet galaxies in the SDSS          (Zhang+, 2007)

Wolf-Rayet galaxies in the Sloan Digital Sky Survey: the metallicity dependence of the initial mass function. Zhang W., Kong X., Li C., Zhou H.-Y., Cheng F.-Z. <Astrophys. J., 655, 851-862 (2007)> =2007ApJ...655..851Z
ADC_Keywords: Galaxies, spectra Keywords: galaxies: abundances - galaxies: starburst - stars: Wolf-Rayet Abstract: We use a large sample of 174 Wolf-Rayet (W-R) galaxies drawn from the Sloan Digital Sky Survey to study whether and how the slope of the stellar initial mass function depends on metallicity. We calculate for each object its oxygen abundance, according to which we divide our sample into four metallicity subsamples. For each subsample, we then measure three quantities: the equivalent width of the Hβ emission line, the equivalent width of the W-R bump around 4650Å, and the W-R bump-to-Hbeta intensity ratio, and compare to the predictions of the same quantities by evolutionary synthesis models of Schaerer & Vacca (1998ApJ...497..618S). Description: The data analyzed in this study are drawn from the SDSS. Imaging is obtained in the u, g, r, i, and z bands with a special purpose drift scan camera mounted on the SDSS 2.5m telescope at Apache Point Observatory. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 135 174 Parameters of the WR sample
See also: J/A+A/485/657 : Physical parameters of Wolf-Rayet galaxies (Brinchmann+, 2008) J/A+AS/136/35 : WR galaxies and HII regions catalog (Schaerer+ 1999) : SDSS Home Page Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 14 A14 --- SDSS-ID The SDSS spectroscopic identification (1) 16- 20 F5.1 --- OII3727 ? The [OII] (3727Å) intensity (2) 22- 24 F3.1 --- H10 ? The H10 (3798Å) intensity (2) 26- 29 F4.1 --- H9 ? The H9 (3836Å) intensity (2) 31- 35 F5.1 --- H8 The H8 (3890Å) intensity (2) 37- 40 F4.1 --- H7 The H7 (3970Å) intensity (2) 42- 45 F4.1 --- Hd The Hδ (4100Å) intensity (2) 47- 50 F4.1 --- Hg The Hγ (4340Å) intensity (2) 52- 55 F4.1 --- OIII4363 ? The [OIII] (4363Å) intensity (2) 57- 61 F5.1 --- OIII4959 ? The [OIII] (4959Å) intensity (2) 63- 67 F5.1 --- OIII5007 ? The [OIII] (5007Å) intensity (2) 69- 73 F5.1 --- Ha ? The Hα (6563Å) intensity (2) 75- 78 F4.1 --- SII6717 The [SII] (6717Å) intensity (2) 80- 83 F4.1 --- SII6731 The [SII] (6731Å) intensity (2) 85- 88 F4.1 --- NII6548 The [NII] (6548Å) intensity (2) 90- 94 F5.1 --- NII6583 The [NII] (6583Å) intensity (2) 96- 99 F4.1 --- OII7320 ? The [OII] (7320Å) intensity (2) 101-103 F3.1 --- OII7330 ? The [OII] (7330Å) intensity (2) 105-111 F7.1 10-20W/m2 Hb Observed Hβ (4861Å) intensity (3) 113-117 F5.1 0.1nm EWHb The Hβ equivalent width 119-122 F4.1 --- W-R W-R bump (4650Å) intensity ratio (2) 124-127 F4.1 0.1nm EW4650 The blue W-R bump equivalent width 129-132 F4.2 [-] O/H The 12+log(O/H) abundance 134-135 A2 --- n_O/H Method used to estimate O/H (4)
Note (1): In the MJD-Plate-Fiber format, from SDSS DR3. Note (2): Relative to Hβ emission line, with I(Hβ)=100. Before these quantities being measured, the observed spectra have been corrected for the Galactic reddening, the internal reddening and the stellar absorption. See the text for details. Blanks denote cases in which Hα or [O III] (4959,5007) are clipped, or the corresponding lines are not detected. Note (3): Corrected for the Galactic reddening, but not for the internal reddening. Note (4): Method used as follows: Te = Te method: from a determination of electron temperature and density N2 = computation as O/H = 1.02log[I(NII)/I(Hα)] + 9.36 (van Zee et al., 1998AJ....116.2805V)
History: From electronic version of the journal Positions have been retrieved with MJD-Plate-Fiber name at
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 10-Dec-2008
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