J/MNRAS/420/3091 Wolf-Rayet population in NGC 5068 (Bibby+, 2012)
The Wolf-Rayet population of the nearby barred spiral galaxy NGC 5068 uncovered
by the Very Large Telescope and Gemini.
Bibby J.L., Crowther P.A.
<Mon. Not. R. Astron. Soc., 420, 3091-3107 (2012)>
=2012MNRAS.420.3091B 2012MNRAS.420.3091B
ADC_Keywords: Galaxies, nearby ; H II regions ; Stars, Wolf-Rayet ; Photometry
Keywords: supernovae: general - stars: Wolf-Rayet - H II regions -
galaxies: individual: NGC 5068 - galaxies: stellar content
Abstract:
We present a narrow-band Very Large Telescope/Focal Reduced
Low-dispersion Spectrograph #1 imaging survey of the SAB(rs)cd spiral
galaxy NGC 5068, located at a distance of 5.45Mpc, from which 160
candidate Wolf-Rayet sources have been identified, of which 59 cases
possess statistically significant λ4686 excesses. Follow-up
Gemini Multi-Object Spectrograph spectroscopy of 64 candidates,
representing 40 per cent of the complete photometric catalogue,
confirms Wolf-Rayet signatures in 30 instances, corresponding to a
47 per cent success rate. 21 out of 22 statistically significant
photometric sources are spectroscopically confirmed.
Description:
NGC 5068 has been imaged with the ESO VLT and Focal Reduced
Low-dispersion Spectrograph #1 (FORS1) covering a field of view of
6.8x6.8arcmin2 with a plate scale of 0.25arcsec/pixel. Both broad-
and narrow-band imaging were obtained on 2008 April 7 under program ID
081.B-0289 (P.I. Crowther). In addition, the Gemini Multi-Object
Spectrograph (GMOS) on the Gemini-South telescope was used to obtain
follow-up spectroscopy in 2009 March-April under program ID
GS-2009A-Q-20 (P.I. Crowther). The R150 grating was placed at a
central wavelength of 510 and 530nm with a dispersion of
∼3.5Å/pix.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 124 164 Catalogue of WR candidates in NGC 5608 ordered
by right ascension
table6.dat 78 29 The flux, luminosity and N(O) stars for the
brightest 29 HII regions in NGC 5068
--------------------------------------------------------------------------------
See also:
III/215 : 7th Catalog of Galactic Wolf-Rayet stars (van der Hucht 2001)
J/MNRAS/381/418 : Wolf-Rayet population in NGC 1313 (Hadfield+, 2007)
J/A+A/518/A29 : WR stars distribution in 2 nearby galaxies (Leloudas+, 2010)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- ID Identification number (1-160, H1-H4)
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 16 F6.3 s RAs Right ascension (J2000)
18 A1 --- DE- Declination sign (J2000)
19- 20 I2 deg DEd Declination (J2000)
22- 23 I2 arcmin DEm Declination (J2000)
25- 28 F4.1 arcsec DEs Declination (J2000)
30- 33 F4.2 --- r/R25 Deprojected distance from the centre of the
galaxy based on R25=3.62'
35- 39 F5.2 mag Vmag ? V magnitude
41- 44 F4.2 mag e_Vmag ? rms uncertainty on Vmag
45- 46 A2 --- n_Vmag Note on Vmag for special objects (1)
48- 52 F5.2 mag B-V ? B-V colour index
54- 57 F4.2 mag e_B-V ? rms uncertainty on B-V
59- 63 F5.2 mag m4684 ? 4684Å filter (HeII) magnitude
65- 68 F4.2 mag e_m4684 ? rms uncertainty on m4684
69- 70 A2 --- n_m4684 Note on m4684 for special objects (1)
72- 76 F5.2 mag col ? 4684Å-4781Å colour index
(HeII-(HeII/6500))
78- 81 F4.2 mag e_col ? rms uncertainty on col
83- 87 F5.3 mag E(B-V) ? Interstellar redenning (2)
89- 94 F6.2 mag VMAG ? Absolute V magnitude (3)
96-101 F6.2 mag M4684 ? Absolute 4684Å filter magnitude (3)
103-112 A10 --- SpType Spectral classification (4)
114-120 A7 --- HII HII region (5)
123-124 I2 --- FC [1/39]? Finding chart number where the source
is located in Appendix A
--------------------------------------------------------------------------------
Note (1): Note as follows:
Ex = Extended
Cr = Crowded
Ed = Edge of chip
Bl = Blended with A24
Note (2): Where spectra have been obtained the derived E(B-V) is used. For
those sources with no nebular lines an average E(B-V)=0.259mag is used.
Note (3): Absolute magnitudes are derived using a distance of 5.45Mpc
(Herrmann et al. 2008ApJ...683..630H 2008ApJ...683..630H).
Note (4): The spectral classification determined from spectroscopy is
listed along with the sources association with a HII region.
Note (5): "Faint" implies nebular-like Hα emission, "bright" implies
a more point source Hα emission while those in the brightest HII
regions in NGC 5068 are referred to using ID numbers in Table 6.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [HII #]
6- 7 I2 --- HII HII number
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 18 F4.1 s RAs Right ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 28 I2 arcsec DEs Declination (J2000)
30- 31 I2 arcsec dap Diameter of the aperture
33- 37 F5.2 10-17W/m2 FHa Hα continuum subtracted flux (1)
39- 43 F5.3 mag E(B-V) ? Interstellar reddenning (2)
45- 49 F5.2 10+31W LHa Hα luminosity (3)
51- 55 F5.2 [ph/s] logQ0 Ionizing flux
57- 59 I3 --- N(O7V) Number of O7V stars
61- 63 A3 --- Hodge Hodge (1974PASP...86..845H 1974PASP...86..845H) designation
65- 78 A14 --- WR WR stars identified within the HII region,
in table2.dat
--------------------------------------------------------------------------------
Note (1): corrected for [NII] emission using Ha/[NII]=0.155.
Note (2): 0.259 for sources with no nebular lines.
Note (3): assuming a distance of 5.45Mpc.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Oct-2012