Chandra ACIS-S3 Spectra of BD+30°3639
The images show the regions used to extract source and background spectra:
- White regions define the sources.
- Red regions define the background areas whose spectrum was subtracted to
the source spectrum.
The spectra and calibration files used in this analysis can be downloaded from
here in a 6.1 MB tar file.
- The X-ray fluxes are derived from the spectral models with the best statistical fit.
Following Maness et al. (2003) we have fitted the ACIS S3 spectrum of BD+30°3639 using optically thin
plasma emission models with different chemical abundances, including:
- A single plasma emission model with nebular abundances.
- A two-temperature plasma emission model with nebular abundances.
- A single plasma emission model with wind abundances.
- A single plasma emission model with modified wind abundances (O and Ne enhanced).
The plasma emission models with nebular abundances produced a defficient spectral fit, even when a
two-temperature model is considered.
The spectral fit with wind abundances is considerably better and the fit is statistically acceptable
when the O and Ne abundances are allowed to vary.
The best-fit implies O and Ne abundances enhanced 3 and 2 times with respect to the O and Ne wind
abundances, respectively.
Source and background regions used for the nebular spectrum.
One thermal component with nebular abundances.
Reduced χ2 = χ2/DoF = 673.1/60 = 11.2
kT = 0.21 keV
NH = 2.6×1020 cm−2
Two thermal components with nebular abundances.
Reduced χ2 = χ2/DoF = 295.1/60 = 5.1
kT1 = 0.105 keV; kT2 = 0.63 keV
NH = 2.1×1021 cm−2
One thermal component with wind abundances.
Reduced χ2 = χ2/DoF = 169.1/60 = 2.8
kT = 0.18 keV
NH = 2.6×1021 cm−2
One thermal component with O and Ne enhanced wind abundances.
Reduced χ2 = χ2/DoF = 89.4.1/60 = 1.5
kT = 0.19 keV
NH = 2.3×1021 cm−2
O = 3.6×Osolar == 2.9×Owind
Ne = 22.2×Nesolar == 2.1×Newind
Absorbed flux:
fabs (0.25−2.5 keV) = 6.6×10−13 ergs cm−2 s−1
fabs (0.45−2.5 keV) = 5.0×10−13 ergs cm−2 s−1
Unabsorbed flux:
FX (0.25−2.5 keV) = 91.1×10−13 ergs cm−2 s−1
FX (0.45−2.5 keV) = 20.7×10−13 ergs cm−2 s−1
Luminosity:
LX (0.25−2.5 keV) = 1.6×1033 ergs s−1
LX (0.45−2.5 keV) = 3.6×1032 ergs s−1
