J/A+A/421/539 VLT spectroscopy of Tol 1214-277 & Tol 65 (Izotov+, 2004)
Deep VLT spectroscopy of the blue compact dwarf galaxies Tol 1214-277 and Tol 65
Izotov Y.I., Papaderos P., Guseva N.G., Fricke K.J., Thuan T.X.
<Astron. Astrophys. 421, 539 (2004)>
=2004A&A...421..539I 2004A&A...421..539I
ADC_Keywords: Galaxies, spectra ; H II regions ; Equivalent widths
Keywords: galaxies: starburst - galaxies: abundances -
galaxies: individual: Tol 1214-277, Tol 65
Abstract:
We present VLT spectroscopic observations with different spectral
resolutions and different slit orientations of the two metal-deficient
blue compact dwarf (BCD) galaxies Tol 1214-277 and Tol 65. The oxygen
abundances in the brightest HII regions of Tol 1214-277 and Tol 65 are
found to be 12+logO/H=7.55±0.01 and 7.54±0.01, or Z☉/24.
The nitrogen-to-oxygen abundance ratios in the two galaxies are
logN/O=-1.64±0.03 and -1.60±0.02 and lie in the narrow range found
for other most metal-deficient BCDs. The helium mass fraction derived
in several HII regions in both galaxies is consistent with a high
primordial helium mass fraction, Yp∼0.244. We confirm the detection of
the high-ionization forbidden emission line [FeV]4227 in the spectrum
of Tol 1214-277. Additionally, weak [NeIV]4725, [FeVI]5146,5177, and
[FeVII]5721,6087 emission lines are detected in the high-resolution
spectrum of Tol 1214-277. The detection of these lines implies the
presence of hard radiation with photon energy in the range ∼4-8Ryd.
Emission lines are detected in the spectra of eight galaxies in the
fields of Tol 1214-277 and Tol 65. Seven of these galaxies are
background objects, while one galaxy has a redshift close to that of
Tol 1214-277. Situated at a projected distance of ∼14.5kpc from
Tol 1214-277, this galaxy is probably a companion of the BCD.
Objects:
----------------------------------------------------------------------
RA (2000) DE Designation(s) (Note)
----------------------------------------------------------------------
12 17 17.1 -28 02 33 Tol 1214-277 (brightest region 1)
12 25 46.9 -36 14 01 Tol 65 = Tol 1223-359 (brightest region 1)
----------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 91 53 Corrected fluxes and equivalent widths of the
emission lines in the high-resolution spectra of the
brightest HII regions in Tol 1214-277 and Tol 65
table3.dat 92 37 Corrected fluxes and equivalent widths of the
emission lines in the low-resolution spectra
of the brightest HII regions in Tol 1214-277
table4.dat 92 38 Corrected fluxes and equivalent widths of the
emission lines in the low-resolution spectra
of the brightest HII regions in Tol 65
addit.dat 55 33 Additional data for tables 2 to 4
table7.dat 26 8 Coordinates of the emission-line galaxies in the
fields of Tol 1214-277 and Tol 65
table8.dat 56 26 Parameters of the emission lines in the spectra of
galaxies in the fields of Tol 1214-277 and Tol 65
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 0.1nm lambda Non-redshifted wavelength
6- 15 A10 --- Ion Emission-line identification
17- 22 F6.4 --- Flux1 Emission-line flux relative to Hbeta in
region 1 of Tol 1214-277 (G1)
24- 29 F6.4 --- e_Flux1 1sigma flux error
31- 36 F6.1 0.1nm EW1 Equivalent width of the emission line in
region 1 of Tol 1214-277
38- 40 F3.1 0.1nm e_EW1 Equivalent width 1sigma error
42- 47 F6.4 --- FHbeta1+2 Emission-line flux relative to Hbeta in
regions 1+2 of Tol 65 (G1)
49- 54 F6.4 --- e_FHbeta1+2 1sigma flux error
56- 61 F6.1 0.1nm EW1+2 Equivalent width of the emission line in
regions 1+2 of Tol 65
63- 65 F3.1 0.1nm e_EW1+2 Equivalent width 1sigma error
67- 72 F6.4 --- Flux3+4 Emission-line flux relative to Hbeta in
regions 3+4 of Tol 65 (G1)
74- 79 F6.4 --- e_Flux3+4 1sigma flux error
81- 86 F6.1 0.1nm EW3+4 Equivalent width of the emission line in
regions 3+4 of Tol 65
88- 90 F3.1 0.1nm e_EW3+4 Equivalent width 1sigma error
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 0.1nm lambda Non-redshifted wavelength
6- 15 A10 --- Ion Emission-line identification
17- 21 F5.3 --- Flux1a Emission-line flux relative to Hbeta in
region 1 of Tol 1214-277 observed in 1999 (G1)
23- 27 F5.3 --- e_Flux1a 1sigma flux error
29- 34 F6.1 0.1nm EW1a Equivalent width of the emission line in
region 1 of Tol 1214-277 observed in 1999
36- 40 F5.3 --- Flux1b Emission-line flux relative to Hbeta in
region 1 of Tol 1214-277 observed in 2000 (G1)
42- 46 F5.3 --- e_Flux1b 1sigma flux error
48- 53 F6.1 0.1nm EW1b Equivalent width of the emission line in
region 1 of Tol 1214-277 observed in 2000
55- 59 F5.3 --- Flux2a Emission-line flux relative to Hbeta in
region 2 of Tol 1214-277 observed in 1999 (G1)
61- 65 F5.3 --- e_Flux2a 1sigma flux error
67- 72 F6.1 0.1nm EW2a Equivalent width of the emission line in
region 2 of Tol 1214-277 observed in 1999
74- 78 F5.3 --- Flux2b Emission-line flux relative to Hbeta in
region 2 of Tol 1214-277 observed in 2000 (G1)
80- 84 F5.3 --- e_Flux2b 1sigma flux error
86- 91 F6.1 0.1nm EW2b Equivalent width of the emission line in
region 2 of Tol 1214-277 observed in 2000
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 0.1nm lambda Non-redshifted wavelength
6- 15 A10 --- Ion Emission-line identification
17- 21 F5.3 --- Flux1 Emission-line flux relative to Hbeta in
region 1 of Tol 65 (G1)
23- 27 F5.3 --- e_Flux1 1sigma flux error
29- 34 F6.1 0.1nm EW1 Equivalent width of the emission line in
region 1 of Tol 65
36- 40 F5.3 --- Flux2 Emission-line flux relative to Hbeta in
region 2 of Tol 65 (G1)
42- 46 F5.3 --- e_Flux2 1sigma flux error
48- 53 F6.1 0.1nm EW2 Equivalent width of the emission line in
region 2 of Tol 65
55- 59 F5.3 --- Flux3 Emission-line flux relative to Hbeta in
region 3 of Tol 65 (G1)
61- 65 F5.3 --- e_Flux3 1sigma flux error
67- 72 F6.1 0.1nm EW3 Equivalent width of the emission line in
region 3 of Tol 65
74- 78 F5.3 --- Flux4 Emission-line flux relative to Hbeta in
region 4 of Tol 65 (G1)
80- 84 F5.3 --- e_Flux4 1sigma flux error
86- 91 F6.1 0.1nm EW4 Equivalent width of the emission line in
region 4 of Tol 65 (G1)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: addit.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 I1 --- Table [2/4] Table number
3- 14 A12 --- Gal Galaxy name
16- 17 A2 --- Res Type of spectral resolution (HR or LR)
19- 26 A8 --- Param Parameter (1)
29- 31 A3 --- Region Region number in the galaxy
32 A1 --- Year [ab] Year of observation a=1999, b=2000
34- 38 F5.3 --- Value Value of the parameter
40- 44 F5.3 --- e_Value rms uncertainty on Value
46- 55 A10 --- x_Value Unit of the Value parameter
--------------------------------------------------------------------------------
Note (1): The parameters are:
F(Hbeta): Observed Hbeta flux, in 10-7W/s/m2
C(Hbeta): Extinction coefficient, in dex
EW(abs): Equivalent width of hydrogen absorption lines, in 0.1nm
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Gal Galaxy name (g1 to g8)
5- 6 I2 h RAh Right ascension (J2000.0)
8- 9 I2 min RAm Right ascension (J2000.0)
11- 14 F4.1 s RAs Right ascension (J2000.0)
17 A1 --- DE- Declination sign (J2000.0)
18- 19 I2 deg DEd Declination (J2000.0)
21- 22 I2 arcmin DEm Declination (J2000.0)
24- 25 I2 arcsec DEs Declination (J2000.0)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Gal Galaxy name (g1 to g8) (1)
4- 7 I4 0.1nm lambda Non-redshifted wavelength
9- 18 A10 --- Ion Emission-line identification
20- 25 F6.1 0.1nm Lobs Observed wavelength
27- 29 F3.1 0.1nm e_Lobs 1sigma error of the observed wavelength
31- 35 F5.1 10-20W/m2/s Flux Observed flux
37- 39 F3.1 10-20W/m2/s e_Flux 1sigma error of the observed flux
41- 43 I3 0.1nm EW Equivalent width of the emission line
45- 46 I2 0.1nm e_EW 1sigma error of the equivalent width
48- 53 F6.4 --- z Redshift
--------------------------------------------------------------------------------
Note (1): Galaxy designations:
g1-g4: galaxies in Tol 1214-277, [FIP2001] GN, N=1-3, in Simbad
g5-g8: galaxies in Tol 65
--------------------------------------------------------------------------------
Global notes:
Note (G1): Fluxes are corrected for underlying stellar absorption
(for hydrogen lines) and interstellar extinction.
--------------------------------------------------------------------------------
Acknowledgements: Yuri Izotov
(End) Patricia Bauer [CDS] 13-Apr-2004