III/157 An Ultraviolet Atlas of Quasar and Blazar Spectra (Kinney+, 1991)
An Ultraviolet atlas of Quasar and Blazar Spectra
Kinney A.L., Bohlin R.C., Blades J.C., York D.G.
<Astrophys. J. Suppl. Ser. 75, 645 (1991)>
=1991ApJS...75..645K 1991ApJS...75..645K
ADC_Keywords: Atlases; Galaxies, Seyfert; QSOs; Spectra, ultraviolet
Abstract:
This atlas contains the ultraviolet spectra of 70 quasars, blazars,
and Seyfert 1 galaxies that were produced by combining over 100 low
resolution spectra from the International Ultraviolet Explorer (IUE)
data archive. The spectra have been extracted with an optimal
algorithm (see Kinney et al. 1991) and co-added to produce spectra
with the best possible signal-to-noise ratio.
Introduction:
The spectra file currently present in this directory are the digital
versions of the spectra that were extracted and co-added for the
Ultraviolet Atlas of Quasar and Blazar Spectra, 1991 (reference above)
The files contain the optimally extracted data which are described in
"Weighted Slit Extraction of Low Dispersion IUE spectra. The optimal
extraction is described in A. L. Kinney, R. C. Bohlin, and J. D. Neill
1991PASP..103..694K 1991PASP..103..694K
Each co-added spectrum consists of the wavelength, quality flag, gross
flux, background flux, gross flux divided by time, absolutely
calibrated net flux, exposure time, and sigma. Details from the
headers which formerly prefixed each spectrum are in headers.dat. A
third file (objects.dat) is also available, which contains information
from Table 1 in the published paper: IAU and alternate designations,
redshift (z), V magnitude, object type, E(B-V), galactic longitude and
latitude, and number of spectra.
The file formats are mostly self explanatory. THE S-AP NOMENCLATURE
INDICATES THE SPECTRA THAT ARE NORMALIZED IN FLUX TO THE L-AP SET
(USUALLY ONE SPECTRUM, see paper for a more detailed explanation) AND
DOES *NOT* MEAN THAT THE SPECTRA WERE OBTAINED IN THE SMALL ENTRANCE
APERTURE. The camera numbers of co-added spectra are listed. Each
co-added spectrum has 8 columns of ASCII numbers with the titles.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
headers.txt 80 403 Information from original headers
objects.dat 60 70 Details on objects included
sp/* . 70 Co-added spectra
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See also:
VI/110 : Final Merged Log of IUE Observations (NASA-ESA, 2000)
Byte-by-byte Description of file: objects.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
-------------------------------------------------------------------------------
1- 2 I02 --- Seq Sequence number
5- 12 A8 --- QSO IAU designation
14- 22 A9 --- Name Alternate designation
24- 28 F5.3 km/s z ? Redshift z
29 A1 --- n_z [a:] Redshift from Veron+Veron
31- 35 F5.2 mag Vmag V magnitude
37- 39 A3 --- Type Type QSO (quasar) SY1 (Seyfert type I)
or BLZ (blazar)
41- 44 F4.2 mag E(B-V) Color excess
45- 51 F7.2 deg GLON Galactic longitude
52- 57 F6.2 deg GLAT Galactic latitude
59- 60 I2 --- Ns Number of spectra used for the Atlas.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: sp/*
-------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- QSO Identification
10- 15 F6.1 0.1nm lambda Wavelength
17- 22 F6.0 --- Qual Quality flag
23- 31 F9.0 --- gFlux Gross flux
34- 40 F7.0 --- bFlux Background flux
45- 50 F6.2 --- net/s Gross-background divided by time
51- 60 E10.3 10mW/m2/nm Flux Absolute calibrated net flux
62- 70 F9.2 s ExpTime Exposure time
74- 80 F7.4 --- sigma *(Example: 2.1 = 210 percent)
--------------------------------------------------------------------------------
Note on sigma:
The SIGMA is the RMS scatter among the co-added spectra at each wavelength.
In qso70.dat, a zero has been added to byte 80 to permit reading this
file with the same format as that for the other files. This zero should be
ignored.
--------------------------------------------------------------------------------
History:
* February 1992: the Spectra were kindly provided by Anne L. Kinney
* 22-Apr-1992: the file objects.dat was added by the CDS.
* 01-Sep-1995: description standardized (Nancy G. Roman)
The file headers.txt is best read as a straight ASCII file.
Acknowlegements:
The undersigned (Nancy G. Roman) thanks Ralph Bohlin for providing
this version of the catalog and substantial advice. She also thanks
Arthur Davidson for providing the information on 1700+643.
(End) Nancy G. Roman [ADC/SSDOO] 01-Sep-1995