J/A+A/660/A34 X-Shooter Spectral Library (XSL). DR3 (Verro+, 2022)
The X-Shooter Spectral Library (XSL): Data Release 3.
Verro K., Trager S.C., Peletier R.F., Lancon A., Gonneau A., Vazdekis A.,
Prugniel P., Chen Y.-P., Coelho P.R.T., Sanchez-Blazquez P., Martins L.,
Arentsen A., Lyubenova M., Falcon-Barroso J., Dries M.
<Astron. Astrophys. 660, A34 (2022)>
=2022A&A...660A..34V 2022A&A...660A..34V (SIMBAD/NED BibCode)
ADC_Keywords: Fundamental catalog ; Stars, standard ; Spectroscopy
Keywords: catalogs - Hertzsprung-Russell and C-M diagrams - stars: general
Abstract:
We present the third data release (DR3) of the X-shooter Spectral
Library (XSL). This moderate-high resolution near-UV to near-IR
(350-2480nm, R∼10000) spectral library is composed of 830 stellar
spectra of 683 stars. DR3 improves upon the previous data release by
providing the combined de-reddened spectra of the three X-shooter
segments over the full 350-2480nm wavelength range. It also
includes additional 20 M dwarf spectra from the ESO archive. We
provide detailed comparisons between this library and Gaia EDR3,
MILES, NGSL, CaT library and (E-)IRTF. The normalised root-mean-square
deviation is better than D=0.05 or 5% for the majority of spectra in
common between MILES (144 spectra of 180), NGSL (112/116) and (E-)IRTF
(55/77) libraries. Comparing synthetic colours of those spectra
reveals only negligible offsets and small rms scatter, such as the
median offset (rms) 0.001±0.040mag in the (box1-box2) colour of the
UVB arm, -0.004±0.028mag in (box3-box4) of the VIS arm, and
-0.001±0.045 mag in (box2-box3) colour between the UVB and VIS
arms, when comparing stars in common with MILES. We also find an
excellent agreement between the Gaia published (BP-RP) colours and
those measured from the XSL DR3 spectra, with a zero median offset and
an rms scatter of 0.037mag for 449 non-variable stars. The unmatched
characteristics of this library, which combines relatively high
resolution, a large number of stars, and an extended wavelength
coverage, will help us to bridge the optical and the near-IR studies
of intermediate and old stellar populations, as well as to probe
low-mass stellar systems.
Description:
The X-shooter spectra cover three wavelength ranges, referred to as
arms: ultraviolet-blue (UVB), visible (VIS) and near-infrared (NIR).
The final data products released as DR3 consist of combined-arm
spectra 350-2477nm, with logarithmic (log10) sampled wavelengths in
the rest-frame.
Each arm has its own resolution: (constant) 13km/s in UVB, 11km/s in
VIS and 16km/s in NIR, but the spectrum in the overlap region of the
arms is smoothed to the lower resolution of the combined spectral
arms. The spectra are provided as FITS binary tables, each containing
three or four columns: the wavelength (in nm), the flux spectrum (in
erg/s/cm2/Å), the dereddened or spline corrected flux spectrum (in
erg/s/cm2/Å) and an error spectrum (in erg/s/cm2/Å). The spectra
which could not be corrected for galactic dust extinction have only
three columns. A set of keywords in the headers of the FITS files keep
track of various steps of the data-reduction and calibration
processes, and of results of the quality assessments. A
(non-exhaustive) list of these keywords is given in Table B.1. of the
paper.
The DR3 spectra are made available as separate sets, separated by
naming convention:
1. xslspectrumX0000_merged.fits - four column binary tables,
[WAVE, FLUX, FLUX_DR, ERR]
2. xslspectrumMD000_merged.fits - new M dwarf spectrum;
four column binary tables [WAVE, FLUX, FLUX_DR, ERR]
3. xslspectrumX0000mergedncl.fits - spectrum is not corrected
for slit flux losses; a three column binary tables [WAVE, FLUX, ERR]
4. xslspectrumX0000mergedscl.fits - spectrum is corrected for
galactic dust extinction and flux losses with a spline function;
a four column binary tables [WAVE, FLUX, FLUX_SC, ERR]
5. xslspectrumX0000mergedncge.fits - spectrum is not corrected
for galactic dust extinction; a three column binary tables
[WAVE, FLUX, ERR]
The table provided contains the list of our stars some observational
properties as described in Table C1 (coordinates, XSL_ID, MJD, arm
missing) of DR2 (Gonneau et al., 2020A&A...634A.133G 2020A&A...634A.133G, Cat.
J/A+A/634/A133) and Table A1 of DR3. The comments about individual
objects from Table C1 of DR3 are also included in this table.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table.dat 311 830 List of our stars some observational properties
as described in Table C1
fits/* . 830 Individual fits spectra
--------------------------------------------------------------------------------
See also:
J/A+A/565/A117 : X-Shooter Spectral Library (XSL). DR1 (Chen+, 2014)
J/A+A/634/A133 : X-Shooter Spectral Library (XSL). DR2 (Gonneau+, 2020)
Byte-by-byte Description of file:table.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 25 A25 --- Star Name of the star
27- 28 I2 h RAh Right ascension (J2000)
30- 31 I2 min RAm Right ascension (J2000)
33- 37 F5.2 s RAs Right ascension (J2000)
39 A1 --- DE- Declination sign (J2000)
40- 41 I2 deg DEd Declination (J2000)
43- 44 I2 arcmin DEm Declination (J2000)
46- 49 F4.1 arcsec DEs Declination (J2000)
51- 55 A5 --- XSLID XSL unique identifier
57- 66 F10.4 d MJD Modified Julian Date
68- 70 A3 --- ArmZero Arm missing
72-110 A39 --- FileName Name of the FITS file in subdirectory fits
112-311 A200 --- Com Comments on individual stars
--------------------------------------------------------------------------------
Acknowledgements:
Kristiina Verro, verro(at)astro.rug.nl
References:
Chen et al., DR1 2014A&A...565A.117C 2014A&A...565A.117C, Cat. J/A+A/565/A117
Gonneau et al., DR2 2020A&A...634A.133G 2020A&A...634A.133G, Cat. J/A+A/634/A133
(End) Patricia Vannier [CDS] 12-Jan-2022