J/AJ/121/169 Imaging and spectroscopy of Tol 1214-277 (Fricke+, 2001)
An imaging and spectroscopic study of the very metal-deficient blue compact
dwarf galaxy Tol 1214-277.
Fricke K.J., Izotov Y.I., Papaderos P., Guseva N.G., Thuan T.X.
<Astron. J., 121, 169-181 (2001)>
=2001AJ....121..169F 2001AJ....121..169F
ADC_Keywords: Abundances ; Galaxies, optical ; H II regions ; Stars, Wolf-Rayet
Keywords: Galaxies: Abundances, Galaxies: Starburst, Galaxies: Stellar Content,
ISM: H II Regions, Stars: Wolf-Rayet
Abstract:
We present a spectrophotometric study based on VLT/FORS I observations
of one of the most metal-deficient blue compact dwarf (BCD) galaxies
known, Tol 1214-277 (Z∼Zsolar/25). The data show that roughly half of
the total luminosity of the BCD originates from a bright and compact
starburst region located at the northeastern tip of a faint dwarf
galaxy with cometary appearance. The starburst has ignited less than 4
Myr ago and its emission is powered by several thousand O7V stars and
∼170 late-type nitrogen Wolf-Rayet stars located within a compact
region with ≲500pc in diameter. For the first time in a BCD, a
relatively strong [Fe V] λ4227 emission line is seen which
together with intense He II λ4686 emission indicates the
presence of a very hard radiation field in Tol 1214-277. We argue that
this extraordinarily hard radiation originates from both Wolf-Rayet
stars and radiative shocks in the starburst region. The structural
properties of the low surface brightness (LSB) component underlying
the starburst have been investigated by means of surface photometry
down to 28 B mag.arcsec-2. We find that, for a surface brightness
level fainter than ∼24.5 B mag.arcsec-2, an exponential fitting law
provides an adequate approximation to its radial intensity
distribution. The broadband colors in the outskirts of the LSB
component of Tol 1214-277 are nearly constant and are consistent with
an age below one Gyr. This conclusion is supported by the comparison
of the observed spectral energy distribution (SED) of the LSB host
with theoretical SEDs.
Objects:
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RA (2000) DE Designation(s)
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12 17 17.1 -28 02 33 Tol 1214-277 = LEDA 39402
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 58 39 Emission line intensities in the brightest
knot of Tol 1214-277
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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- 24 A24 --- --- [Wavelength and Ion name]
26- 29 I4 0.1nm lambda ? Wavelength
31- 44 A14 --- Ion ? Ion species name
46- 51 F6.4 1.4x10-17W/m2 Flux Flux (in units of Hβ flux) (1)
53- 58 F6.4 1.4x10-17W/m2 e_Flux ? Uncertainty in Flux
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Note (1): Flux is relative to Hβ, which is 1.40x10-14.ergs/s/cm2
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Laurent Cambresy [CDS] 22-Jul-2004