J/ApJS/266/41 HST/STIS low-resolution stellar library (Pal+, 2023)
HST Low-resolution Stellar Library.
Pal T., Khan I., Worthey G., Gregg M.D., Silva D.R.
<Astrophys. J. Suppl. Ser., 266, 41 (2023)>
=2023ApJS..266...41P 2023ApJS..266...41P
ADC_Keywords: Spectra, ultraviolet; Abundances, [Fe/H]; Photometry, UBV;
Radial velocities; Magnitudes, absolute; Extinction
Keywords: Hubble Space Telescope ; Stellar chromospheres
Abstract:
In order to provide fundamental stellar spectra that extend into the
UV, Hubble Space Telescope's Space Telescope Imaging Spectrograph
targeted 556 stars via proposals GO9088, GO9786, GO10222, and GO13776.
Exposures through three low-resolution gratings provide wavelength
coverage from 0.2<λ<1µm at λ/Δλ∼1000.
The UV grating (G230LB) scatters red light that results in unwanted
signal, especially in cool stars. We applied scattered-light
corrections and flux corrections arising from pointing errors relative
to the center of the 0.2" slit based on Worthey et al. We present
513 fully reduced stellar spectra, fluxed, dereddened, and cross
correlated to zero velocity. Because of the broad spectral range, we
can simultaneously study Hα and MgIIλ2800, indicators of
chromospheric activity. Their behaviors are decoupled. Besides three
cool dwarfs and one giant with mild flares in Hα, only Be stars
show strong Hα emission. Mg2800 emission, however, strongly
anticorrelates with temperature such that warm stars show absorption
and stars cooler than 5000K universally show chromospheric emission
regardless of dwarf/giant status or metallicity. Transformed to Mg2800
flux emerging from the stellar surface, we find a correlation with
temperature with approximately symmetric astrophysical scatter.
Previous work had indicated a basal level with asymmetric scatter to
strong values. The discrepancy is primarily due to our improved
treatment of extinction. We confirm statistically significant time
variability in Mg2800 strength for one star.
Description:
This paper presents a new reduction of the Next Generation (HST/STIS
low resolution) Spectral Library that includes updated flux
calibration work, updated scattered-light corrections, and an increase
in sample size (from 345 to 513) due to the inclusion of stars from
run GO13776.
During the orbit in which they were targeted, the Next Generation
Spectral Library (NGSL; Gregg+ 2006hstc.conf..209G) stars were
observed by cycling through three different gratings. G230LB sees in
UV (central wavelength of 2375Å), G430L sees in blue (central
wavelength of 4300Å) and G750L sees in red (central wavelength of
7751Å). The three gratings overlap at 2990-3060Å and 5500-5650Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 128 513 Stellar metadata
sp/* . 513 Individual spectra in FITS format
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See also:
III/92 : A Library of Stellar Spectra (Jacoby+ 1984)
J/ApJS/82/197 : Mean UV Spectra of Stellar Groups (Fanelli+ 1992)
J/ApJS/94/687 : Old stellar populations. V. (Worthey+, 1994)
J/A+AS/125/229 : A standard stellar library (Lejeune+ 1997)
J/A+AS/130/65 : A standard stellar library. II. (Lejeune+ 1998)
J/MNRAS/298/525 : Stellar evolution models for Z = 0.0001 to 0.03 (Pols+ 1998)
J/A+AS/139/555 : Catalogue and Bibliography of UV Cet stars (Gershberg+ 1999)
J/A+A/374/1085 : Mg II K line Wilson-Bappu relationship (Cassatella+, 2001)
J/ApJS/152/251 : Indo-US library of coude feed stellar sp. (Valdes+, 2004)
J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)
J/ApJ/657/1046 : Synthetic Mid-UV sp. indices of stars (Chavez+, 2007)
J/A+A/469/309 : Activity in late-type stars (Cincunegui+, 2007)
J/A+A/483/903 : Mount Wilson index for F-K stars (Buccino+, 2008)
J/MNRAS/414/418 : Chromospheric Mg II h+k flux of evolved stars (Perez+, 2011)
J/ApJS/193/1 : UBVRIJHK color-temperature calibration (Worthey+, 2011)
J/A+A/525/A71 : Atmospheric parameters for 1273 stars (Wu+, 2011)
J/A+A/538/A143 : Atmospheric param. of stars for UV models (Koleva+, 2012)
J/A+A/549/A129 : Equivalent widths of cool stars (Cesetti+, 2013)
J/A+A/551/L8 : Chromospheric activity of field stars (Pace, 2013)
J/A+A/566/A66 : Correlation of logR'HK with logIHa (Gomes da Silva+, 2014)
J/A+A/561/A36 : The LickX Spectra library (Worthey+, 2014)
J/A+A/615/A115 : HST Hot Star Library (Khan+, 2018)
J/MNRAS/514/4300 : Late-type dwarfs logR'HK and magnetic fields (Brown+, 2022)
J/A+A/658/A57 : F-G-K stars activity indicators (Meunier+, 2022)
J/A+A/660/A34 : X-Shooter Spectral Library (XSL). DR3 (Verro+, 2022)
http://astro.wsu.edu/hststarlib/ : HST/STIS stellar spectral library homepage
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Name Simbad identifier
23- 31 A9 --- OName Header identifier
33- 37 I5 K Teff [2377/32902] Effective temperature
39- 43 F5.2 [cm/s2] logg [-0.3/5.34] log surface gravity
45- 49 F5.2 [Sun] [Fe/H] [-2.11/1] Metallicity
51- 55 F5.2 mag Bmag [1.29/13]? Apparent B band Vega magnitude
57- 61 F5.2 mag Vmag [1.19/14]? Apparent V band Vega magnitude
63- 68 F6.2 mas plx [0.25/768.5] Simbad parallax
70- 74 F5.2 mag VMag [-9.81/15.6]? Absolute V band Vega magnitude
76- 80 F5.2 pix dSlit [-1/1.1] Slit off-center correction
82- 87 F6.1 km/s RVel [-389/340] Radial velocity
89- 94 F6.1 ct-1 K0 [0/4843] Scattered light count rate
at 2000Å; ADU
96- 99 F4.2 mag Av [0/3.1] The V band extinction
101 I1 --- f_Av [1/3] Note on Av (1)
103-108 F6.3 mag Mg2800 [-5.8/2.5]? The MgII 2800 index
110-115 F6.3 mag Ha [-0.54/0.4]? The Hα index
117-122 F6.3 mag Hb [-0.5/0.43]? The Hβ index
124-128 A5 --- Note Note(s) for objects noted in Section 5.2 (2)
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Note (1): Note on Av as follows:
1 = Koleva * Vazdekis (2012, J/A+A/538/A143);
2 = Our derivation based on comparison with synthetic templates;
3 = Drimmel et al. (2003A&A...409..205D 2003A&A...409..205D).
Note (2): Note as follows:
1 = noisy;
2 = possible extraction error;
3 = chemically peculiar;
4 = binary that does or may suffer from compositeness;
5 = photometric variable.
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History:
From electronic version of the journal
Spectra download from http://astro.wsu.edu/hststarlib/
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 14-Aug-2023