The archive (tar file) of the
data set presented in the paper can be downloaded here.
The file nameincludes
the epoch with
respect to B-band maximum light. Each file includes an ascii table
with three columns: Wavelength
(de-redshifted), Observed Flux, Statistical Error (Based on the optimal
extraction algorithm).
Brief summary of the
data reduction steps:
SN~1999aa's host galaxy, NGC~2595, is at
redshift z= 0.0146. All the data presented in the
archive were de-reshifted using this redshift value.
The data set consists of 25 optical spectra, obtained using five
different instruments, extending from day -11 to
day +58 (in this archive all phases are expressed with respect to
B-band maximum). In most cases, the spectra were acquired using
different instrumental
settings for the blue and red parts of the spectrum to avoid possible
second-order contamination. Hence, the 25 fully reduced spectra are the
combinations of both blue and red parts. Spectra were taken with the
slit rotated to a position angle close to the parallactic angle at the
mid-point of each exposure.
The data were reduced using standard IRAF routines. The two-dimensional
images were bias-subtracted and flat-fielded. In most of the cases, the
observations were split into multiple exposures in order to allow
elimination of cosmic rays from the final spectrum. The
background sky and the underlying host galaxy were fitted, subtracted,
and extracted for systematics checks of the
wavelength calibration. The supernova spectrum was extracted using
the variance weighted optimal aperture extraction method. Wavelength and flux calibration
were applied to
the one-dimensional extracted spectra using arc and standard star
observations taken with the same instrumental setting and during the
same night as the science observations. The accuracy of the wavelength
calibration was checked against the extracted sky spectra and generally
found to agree to within 2~\AA. Mean smoothed atmospheric extinction
corrections for each observatory were applied. No correction was
yet been made for telluric features or residual fringing. Synthetic
spectrophotometry was
computed to check the overall accuracy of the flux calibration against
publicly available photometric data and found to agree within the
quoted statistical uncertainties.
The Galactic reddening in the direction of SN 1999aa
is E(B-V) = 0.04 mag. The correction for Galactic extinction was
performed using the standard procedure (Schlegel, et al., ApJ
500, 525 (1998)) assuming R_V = 3.1.
No
host galaxy reddening correction was applied.
Citation Requirement:
Any publication that makes use of this data should cite: G. Garvini, AJ
128, 3874 (2004). Data made available by the Supernova Cosmology
Project.
