J/ApJ/695/580 Oxygen abundance in M83 (Bresolin+, 2009)
The flat oxygen abundance gradient in the extended disk of M83.
Bresolin F., Ryan-Weber E., Kennicutt R.C., Goddard Q.
<Astrophys. J., 695, 580-595 (2009)>
=2009ApJ...695..580B 2009ApJ...695..580B
ADC_Keywords: Abundances ; H II regions ; Galaxies, optical ; Spectroscopy ;
Ultraviolet
Keywords: galaxies: abundances - galaxies: individual (M83) - galaxies: ISM
Abstract:
We have obtained deep multiobject optical spectra of 49 HII regions in
the outer disk of the spiral galaxy M83 (=NGC 5236) with the FORS2
spectrograph at the Very Large Telescope. The targets span the range
in galactocentric distance between 0.64 and 2.64 times the R25
isophotal radius (5.4-22.3kpc), and 31 of them are located at R>R25,
thus belonging to the extreme outer disk of the galaxy, populated by
UV complexes revealed recently by the Galaxy Evolution Explorer
satellite. In order to derive the nebular chemical abundances, we
apply several diagnostics of the oxygen abundance, including R23,
[NII]/[OII], and the [OIII]λ4363 auroral line, which was
detected in four HII regions.
Description:
Candidate HII regions in the outer disk of M83 were selected from deep
Hα images obtained at the 90 inch Bok telescope of the Steward
Observatory with the 90 Prime camera. Several of these HII regions
have a counterpart in the list of UV-emitting clusters detected by
GALEX (Thilker et al. 2005ApJ...619L..79T 2005ApJ...619L..79T; Gil de Paz et al.
2007ApJ...661..115G 2007ApJ...661..115G).
Optical spectra were acquired with FORS2 at the Very Large Telescope
of the European Southern Observatory on Paranal. Objects distributed
in four nonoverlapping 6.8'x6.8' fields were observed in service mode
between 2007 May 10 and 2007 June 19.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 38 49 HII region sample
table2.dat 55 49 Reddening-corrected fluxes
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See also:
J/AJ/136/479 : IRAC observations of M83 extended UV disk (Dong+, 2008)
J/ApJS/173/538 : XUV-Disk galaxies in the Local Universe (Thilker+, 2007)
J/ApJS/173/185 : GALEX ultraviolet atlas of nearby galaxies (Gil de Paz+,
2007)
J/A+A/415/155 : Oxygen abundances in the Galactic disk (Bensby+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID HII region number
4- 5 I2 h RAh Hour of right ascension (J2000)
7- 8 I2 min RAm Minute of right ascension (J2000)
10- 14 F5.2 s RAs Second of right ascension (J2000)
16 A1 --- DE- Declination sign (J2000)
17- 18 I2 deg DEd Degree of declination (J2000)
20- 21 I2 arcmin DEm Arcminute of declination (J2000)
23- 26 F4.1 arcsec DEs Arcsecond of declination (J2000)
28- 31 F4.2 --- R/R25 Galactocentric distance in units of
R25=6.44arcmin
33- 35 A3 --- --- [XUV]
37- 38 I2 --- XUV ? Gil de Paz et al. identification
(2007ApJ...661..115G 2007ApJ...661..115G)
(<[GMB2007] NGC 5236 XUV NN> in Simbad)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID HII region number
4- 7 I4 --- F[OII] ? [OII]3727 line flux in units of Hβ=100
9- 11 I3 --- e_F[OII] ? [OII]3727 uncertainty
13- 15 I3 --- F[OIII] Flux of [OIII]5007 line in units of Hβ=100
17- 18 I2 --- e_F[OIII] Uncertainty of [OIII]5007
20- 22 I3 --- F[NII] Flux of [NII]6583 line in units of Hα=286
24- 25 I2 --- e_F[NII] Uncertainty of [NII]6583
27- 29 I3 --- F[SII] Flux of [SII]6717+6731 lines in units of
Hα=286
31- 32 I2 --- e_F[SII] Uncertainty of [SII]6717+6731
34- 37 F4.1 --- F[ArIII] ? Flux of [ArIII]7135 in units of Hα=286
39- 42 F4.1 --- e_F[ArIII] ? Uncertainty of [ArIII]7135
44- 50 E7.2 mW/m2 FHbeta Hβ line flux in erg/s/cm2 (1)
52- 55 F4.2 mag c(Hb) Extinction value (1)
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Note (1): The extinction correction has been applied to F(Hβ) and
the error on c(Hβ) has been propagated to the line fluxes.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 29-Apr-2011