J/ApJS/191/301 Spitzer Atlas of Stellar Spectra (SASS) (Ardila+, 2010)
The Spitzer Atlas of Stellar Spectra (SASS).
Ardila D.R., Van Dyk S.D., Makowiecki W., Stauffer J., Song I., Rho J.,
Fajardo-Acosta S., Hoard D.W., Wachter S.
<Astrophys. J. Suppl. Ser. 191, 301 (2010)>
=2010ApJS..191..301A 2010ApJS..191..301A
ADC_Keywords: Atlases ; Spectra, infrared ; Spectra, millimetric/submm
Mission_Name: Spitzer
Keywords: astronomical databases: miscellaneous - catalogs -
Hertzsprung-Russell and C-M diagrams - stars: atmospheres - stars:
fundamental parameters - techniques: spectroscopic
Abstract:
The Spitzer Atlas of Stellar Spectra (SASS) includes 159 stellar
spectra (5 to 32um; R∼100) taken with the Infrared Spectrograph
(IRS) on the Spitzer Space Telescope. It gathers representative
spectra of a broad section of the Hertzsprung-Russell diagram,
intended to serve as a general stellar spectral reference in the
mid-infrared. It includes stars from all luminosity classes, as well
as Wolf-Rayet (WR) objects. Furthermore, it includes some objects of
intrinsic interest, like blue stragglers and certain pulsating
variables. All the spectra have been uniformly reduced.
Description:
From IRS Staring observations in the Spitzer archive we selected those
stellar targets that had been observed with all the low-resolution IRS
modules. We did not include known young stars with circumstellar
material, stars known to harbor debris disks, or objects classified in
SIMBAD as RS CVn, Be stars, or eclipsing binaries. We have also
avoided classes already fully described with IRAS, ISO, or Spitzer,
such as Asymptotic Giant Branch stars and rejected targets presenting
IR excesses. However, note that in the case of very massive and/or
evolved stars there are few objects presenting a pure photospheric
spectrum.
A few stars are specifically selected for their intrinsic interest
regardless of their IR excess and even if the Atlas already contained
another star with the same spectral type. The spectral coverage only
reaches to 14um in the case of very late spectral classes (late M, L
and T dwarfs) and some WR stars for which the long wavelength modules
are unusable or not present in the archive.
The spectral types have been taken from (in order of priority):
* NStED (http://nsted.ipac.caltech.edu/),
* NStars (http://nstars.nau.edu/nau_nstars/about.htm),
* the Tycho-2 Spectral Type Catalog (Cat. III/231)
* SIMBAD.
For certain types of objects, we have used specialized catalogs
as the source of the spectral types.
The data were processed with the Spitzer Science Center S18.7.0
pipelined and corrected for teardrop effects, slit position
uncertainties, residual flat-field errors, residual model errors,
24um flux deficit (1), fringing, and order mismatches. The Atlas files
contain an error value for each wavelength, intended to represent the
random 1sig error at that wavelength. This is the error provided by
the SSC's S18.7.0 pipeline and propagated along the reduction
procedure. The treatment of errors remains incomplete in this pipeline
(2). The errors provided here should be considered carefully, before
propagating them into further calculations. However, the processing
insures that the spectra do not have strong spurious emission or
absorption lines in large signal-to-noise regions.
(1) http://ssc.spitzer.caltech.edu/irs/irsinstrumenthandbook/102/
#Toc253561116
(2) http://ssc.spitzer.caltech.edu/irs/irsinstrumenthandbook/
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 368 159 Star list
sptbl/* . 159 Individual spectra
spfits/* . 159 Individual spectra in fits
spgif/* . 159 Individual spectra in gif
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Byte-by-byte Description of file: table1.dat
-------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Order Order for website tablexi
6- 8 I3 --- X Index for plot
10- 25 F16.8 Lsun Lum Luminosity
27- 41 A15 --- SpType Spectral type (our decision) (outside key)
43- 59 A17 --- Dir Dir Name (primary key)
61- 83 A23 --- Name Atlas NAME 1 (Simbad)
85-110 A26 --- Name1W Atlas NAME 1 (for website)
112-138 A27 --- Name2W Atlas NAME 2 (for website)
140-144 F5.2 mag B-V ?=- Simbad B-V colour index
145 A1 --- --- [/]
146-149 F4.2 mag B-V2 ? Second value for B-V colour index (1)
151-155 F5.2 mag Jmag ?=- 2MASS J magnitude
156 A1 --- --- [/]
157 A1 --- Jmag2 [-] Second value for Jmag (1)
159-163 F5.2 mag Hmag ?=- 2MASS H magnitude
164 A1 --- --- [/]
165 A1 --- Hmag2 [-] Second value for Hmag (1)
167-171 F5.2 mag Kmag ?=- 2MASS K magnitude
172 A1 --- --- [/]
173 A1 --- Kmag2 [-] Second value for Kmag (1)
175-182 E8.3 Jy F8um ?=- Spitzer/IRAC 8.0um flux (2)
184-191 E8.3 Jy F24um ?=- Spitzer/MIPS 24um flux (3)
193-197 F5.2 [-] [Fe/H] ?=- Metallicity (4)
199-268 A70 ---- Com Comments for website (5)
270-271 I2 --- r_SpType ? Reference for SpType (6)
273-277 A5 --- KSPW KSPW ISO-based classification (7)
279-307 A29 --- spFile Text spectrum file, in subdirectory sptbl
309-338 A30 --- FITSfile FITS spectrum file, in subdirectory spfits
340-368 A29 --- gifFile GIF spectrum file, in subdirectory spgif (8)
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Note (1): For GJ65AB = BL Cet + UV Cet (Seq=12), the first values are for BL Cet
and the second ones for UV Cet.
Note (2): Flux at 7.872um in the IRAC4 band.
Note (3): Flux at 23.68um in the MIPS24 band.
Note (4): From the Geneva-Copenhagen Survey of the Solar neighbourhood
(Nordstrom et al., 2004, Cat. V/117).
Note (5): Comments with the abbreviations:
Strong silicate = Broad absorption feature present at 10um
Non-photometric = Non-photospheric, The spectral slope is inconsistent
with an unreddened naked photosphere
SWS = The target has an IR type - indicated in parenthesis -
in Kraemer et al. (2002ApJS..140..389K 2002ApJS..140..389K)
Note (6): Spectral type taken from the following reference:
1 = van der Hucht (2001NewAR..45..135V 2001NewAR..45..135V, Cat. III/215)
2 = Torres-Dodgen et al. (1988AJ.....96.1076T 1988AJ.....96.1076T, Cat. III/143)
3 = Breysacher et al. (1999A&AS..137..117B 1999A&AS..137..117B)
4 = Maiz-Apellaniz et al. (2004, Cat. J/ApJS/151/103)
5 = Walborn (1972AJ.....77..312W 1972AJ.....77..312W)
6 = Hanson et al. (2005, Cat. J/ApJS, 161, 154)
7 = van Genderen (2001, Cat. J/A+A/366/508)
8 = de Jager (1998A&ARv...8..145D 1998A&ARv...8..145D)
9 = Stahl et al. (2003A&A...400..279S 2003A&A...400..279S)
10 = Beauchamp et al. (1994, Cat. J/ApJS/93/187)
11 = Jones (1972ApJ...178..467J 1972ApJ...178..467J)
12 = Abt et al. (1984ApJ...285..247A 1984ApJ...285..247A)
13 = Cushing et al. (2006ApJ...648..614C 2006ApJ...648..614C)
Note (7): KSPW system, Level1.Level2:
Level 1 :
1 = Naked stars. Photospheric emission with no apparent influence from
circumstellar dust dominates these spectra.
2 = Stars with dust. The SEDs are primarily photospheric at shorter
wavelengths, but they also show noticeable or significant dust
emission at longer wavelengths.
3 = Warm, dusty objects. Sources dominated by emission from warm dust.
4 = Cool, dusty objects. These objects are dominated by cooler dust
emission, the peak of which occurs within the SWS spectral
range but longward of ∼20um.
Level 2 :
N = no molecular bands
NO = CO and/or SiO absorptions
SA = Silicate absorption (10-12um)
CE = Carbon-rich dust emission, primarily from SiC (11.5um)
F = Basically featureless
Fe = Basically featureless with emission lines
SEa = Silicate (or oxygen-rich) dust emission (10-12 and 18-20um)
E = Strong emission lines
: = Uncertain (either noisy or odd)
Note (8): The vertical axis of the plot is such that a pure Rayleigh-Jeans
tail will result in a flat spectrum.
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Byte-by-byte Description of file(#): sptbl/*
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
5- 7 A3 --- Order Order in which the wavelength is detected
(LL1, LL2, SL1 or SL2) (1)
15- 22 F8.5 um lambda Wavelength
31- 38 F8.5 Jy Flux Flux
47- 53 F7.5 Jy e_Flux rms uncertainty on flux
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Note (1): Wavelength ranges used as follows:
SL2 = (Short-Low, order 2) Range= 5.2 - 7.55um
SL1 = (Short-Low, order 1) Range= 7.58-14.29um
LL2 = (Long-Low, order 2) Range=14.24-20.59um,
From 19.35 to 20.59um, the bonus order is used instead of LL2.
In this region, the bonus order presents fewer rogue pixels.
LL1 = (Long-Low, order 1) Range=20.59-35.00um
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Acknowledgements:
David Ardila, ardila(at)ipac.caltech.edu
History:
* 06-Dec-2010: Original data
* 17-Dec-2010: in table1, Stephenson 2 #5 corrected into
2MASS J18390805-0605244
* 07-Oct-2011: Headers corrected and new table1 (from author)
(End) David Ardila [NASA HSC, IPAC, Caltech], Patricia Vannier [CDS] 03-Dec-2010