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J/A+A/615/A115            HST Hot Star Library                     (Khan+, 2018)

Hot Star Extension to the Hubble Space Telescope Stellar Spectral Library. Khan I., Worthey G. <Astron. Astrophys. 615, A115 (2018)> =2018A&A...615A.115K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, O ; Stars, horizontal branch ; Stars, giant ; Spectroscopy Keywords: atlases - stars: horizontal branch - stars: AGB and post-AGB - stars: early type - ISM: dust, extinction - Hertzsprung-Russell and C-M diagrams Abstract: Libraries of stellar spectra find many uses in astrophysics, from photometric calibration to stellar population synthesis. We present low resolution spectra of 40 stars from 0.2 micrometers (ultraviolet) to 1.0 micrometers (near infrared) with excellent fluxing. The stars include normal O-type stars, helium-burning stars, and post-asymptotic giant branch (PAGB) stars. Spectra were obtained with the Space Telescope Imaging Spectrograph (STIS) installed in the Hubble Space Telescope (HST) using three low resolution gratings, G230LB, G430L, and G750L. Cosmic ray hits and fringing in the red were corrected. A correction for scattered light was applied, significant only for our coolest stars. Cross-correlation was used to bring the spectra to a common, final, zero velocity wavelength scale. Finally, synthetic stellar spectra were used to estimate line of sight dust extinction to each star, and a five-parameter dust extinction model was fit, or a one-parameter fit in the case of low extinction. These spectra dovetail with the similar Next Generation Stellar Library (NGSL) spectra, extending the NGSL's coverage of stellar parameters, and extending to helium burning stars and stars that do not fuse. The fitted dust extinction model showed considerable variation from star to star, indicating variations in dust properties for different lines of sight. Interstellar absorption lines are present in most stars, notably MgII. Description: Fully reduced spectra (41 observations of 40 stars) of the hot star library are presented, averaged over all three HST/STIS settings to contiguously span the entire wavelength coverage. They are presented in a rebinned, logarithmic wavelength scale [log lambda(Angstroms)] for pixel number one is 3.215 and the logarithmic delta is 0.0002) and also in a ragged list of wavelengths corresponding to the native instrumental pixels. Units for spectra and errors: milliWatt/s/m2/Angstroem, or, equivalently, erg/s/cm2/Angstroem. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tableb1.dat 149 41 List of the 40 newly observed stars fits/* 0 41 Individual fits spectra
Description of file: fits/* Byte-by-byte description of primary data (extension 0): ------------------------------------------------------------------------------- Col units label Explanation ------------------------------------------------------------------------------- 1 mW/s/m+2/Angstroem F_lambda dust corrected flux 2 mW/s/m+2/Angstroem err_Flam dust corrected flux uncertainty 3 mW/s/m+2/Angstroem F_lambda raw flux (before correction) 4 mW/s/m+2/Angstroem err_Flam raw flux uncertainty 5 unitless ratio extinction model extinction curve ------------------------------------------------------------------------------- Byte by byte description of extension 1: ------------------------------------------------------------------------------- Col Units Label Explanation ------------------------------------------------------------------------------- 1 Angstroem wavelength wavelength 2 mW/s/m+2/Angstroem F_lambda dust corrected flux 3 mW/s/m+2/Angstroem err_Flam dust corrected flux uncertainty 4 mW/s/m+2/Angstroem F_lambda raw flux (before correction) 5 mW/s/m+2/Angstroem err_Flam raw flux uncertainty 6 unitless ratio extinction model extinction curve ------------------------------------------------------------------------------- Byte by byte description of extension 2: ------------------------------------------------------------------------------- Col Units Label Explanation ------------------------------------------------------------------------------- 1 --- obs_set HST observation label ------------------------------------------------------------------------------- Byte-by-byte Description of file: tableb1.dat
Bytes Format Units Label Explanations
1- 17 A17 --- Type Type 19- 20 I2 --- N Internal catalog number based on the 70 SNAP-mode candidate stars (1) 22- 36 A15 --- Name Name of the star 38- 43 F6.3 mag Vmag apparent magnitude through the V filter 45- 50 F6.3 mag B-V B-V colour index 51 A1 --- n_B-V [*] * when 2MASS J-K colour index instead of B-V in B-V column 53- 58 I6 K Teff Effective temperature 60- 63 F4.2 [cm/s2] logg Surface gravity 65- 68 F4.2 mag AV Extinction in V 70- 73 F4.2 --- R ? Ratio of total to selective extinction at V 75- 78 F4.2 um-1 x0 ? Bump position 80- 83 F4.2 um-1 gamma ? Bump width 85- 89 F5.2 --- cs ? Bump strength 91-129 A39 --- Ref Reference 131-149 A19 --- FileName Name of the file with spectra in subdirectory fits
Note (1): The internal catalog number becomes the HST dataset number if you prepend the characters ocy5, so that, for example, star 33 is HST dataset ocy533.
Acknowledgements: Guy Worthey, gworthey(at)
(End) Patricia Vannier [CDS] 09-Apr-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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