J/ApJ/602/200 HII regions abundances in blue compact galaxies (Izotov+, 2004)
Systematic effects and a new determination of the primordial abundance of
4He and dY/dZ from observations of blue compact galaxies.
Izotov Y.I., Thuan T.X.
<Astrophys. J., 602, 200-230 (2004)>
=2004ApJ...602..200I 2004ApJ...602..200I
ADC_Keywords: Galaxies, spectra ; H II regions ; Abundances
Keywords: galaxies: abundances - galaxies: irregular - galaxies: ISM -
H II regions - ISM: abundances
Abstract:
We use spectroscopic observations of a sample of 82 HII regions in
76 blue compact galaxies to determine the primordial helium abundance
Yp and the slope dY/dZ from the Y-O/H linear regression. To improve
the accuracy of the dY/dZ measurement, we have included new
spectrophotometric observations of 33 HII regions that span a large
metallicity range, with oxygen abundance 12+log(O/H) varying between
7.43 and 8.30 (Z☉/30≤Z≤Z☉/4). Most of the new galaxies
were selected from the First Byurakan, the Hamburg/SAO, and the
University of Michigan objective prism surveys.
Description:
We have obtained new high signal-to-noise ratio spectrophotometric
observations for 33 HII regions in 31 BCGs with the Kitt Peak 4m
telescope on the nights of 2002 December 30-31 and 2003 January 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 31 General parameters of galaxies
refs.dat 71 27 References
table3.dat 89 1389 HII regions emission line intensities and
equivalent widths
table4.dat 57 1221 HII regions ionic and total heavy element and
helium abundances
table5.dat 57 89 Sample used for primordial helium abundance
determination
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See also:
J/AZh/79/867 : Abundances of HII regions in blue galaxies (Holovatyy+, 2002)
J/ApJ/511/639 : Abundances in blue compact galaxies (Izotov+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Galaxy name (1)
15- 16 I2 h RAh Right ascension (J2000.0)
18- 19 I2 min RAm Right ascension (J2000.0)
21- 24 F4.1 s RAs Right ascension (J2000.0)
26 A1 --- DE- Declination sign (J2000.0)
27- 28 I2 deg DEd Declination (J2000.0)
30- 31 I2 arcmin DEm Declination (J2000.0)
33- 34 I2 arcsec DEs Declination (J2000.0)
36- 39 F4.1 mag pgmag ? Photographic magnitude
41- 47 F7.5 --- z Redshfit, derived from spectra in this paper
49- 55 F7.5 --- e_z rms uncertainty on z
57- 61 F5.1 mag PGMAG ? Absolute photographic magnitude (2)
63- 78 A16 --- OName Other names
80- 84 A5 --- r_Name References, in refs.dat file
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Note (1): CGCG 007-025 = Z 7-25 in Simbad
Note (2): All objects are assumed to be at their redshift distances with
H0=75km/s/Mpc.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 50 A27 --- Aut Author's name
51- 71 A21 --- Com Comments
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Galaxy name
15 I1 --- n_Name [1/2]? Number of the HII region when two
different HII regions were extracted.
17- 20 I4 0.1nm Lambda Wavelength
22- 35 A14 --- Ion Ion species
37- 41 F5.3 ---- Hbec Hβ extinction coefficient
43- 51 E9.3 mW/m2 FHbeta Uncorrected Hβ line flux in erg/cm2/s
53- 56 F4.2 0.1nm EWHbeta Hβ absorption line equivalent width
58- 63 F6.2 --- Flux ? Observed flux relative to Hβ
65- 69 F5.2 --- e_Flux ? Error in Flux
71- 76 F6.2 --- Fluxc ? corrected flux relative to Hβ (1)
78- 82 F5.2 --- e_Fluxc ? Error in Fluxc
84- 89 F6.1 0.1nm EW ? Equivalent width in Angstroms
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Note (1): Corrected for both reddening Whitford (1958AJ.....63..201W 1958AJ.....63..201W)
and underlying hydrogen stellar absorption.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Galaxy name
15 I1 --- n_Name [1/2]? Number of the HII region when two
17- 37 A21 --- Prop Property and units
39- 48 F10.4 --- Value ? Value of the property
50- 57 F8.4 --- e_Value ? Error in Value
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Galaxy name
15 A1 --- n_Name [1/2]? Number of the HII region when two
different HII regions were extracted
17- 21 F5.2 10+4 O/H O/H abundance
23- 26 F4.2 10+4 e_O/H rms uncertainty on O/H
28- 33 F6.2 10+6 N/H N/H abundance
35- 39 F5.2 10+6 e_N/H rms uncertainty on N/H
42- 47 F6.4 --- Y Y abundance
49- 54 F6.4 --- e_Y rms uncertainty on Y
56- 57 I2 --- r_O/H References, in refs.dat file
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 06-Apr-2004