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6111. Spectra of Vega, Sirius, GD153, and HD209458
ID:
ivo://CDS.VizieR/J/AJ/146/68
Title:
Spectra of Vega, Sirius, GD153, and HD209458
Short Name:
J/AJ/146/68
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper extends synthetic photometry to components of binary star systems. The paper demonstrates accurate recovery of single star photometric properties for four photometric standards, Vega, Sirius, GD153, and HD209458, ranging over the HR diagram, when their model synthetic spectra are placed in fictitious binary systems and subjected to synthetic photometry processing. Techniques for photometric distance determination have been validated for all four photometric standards.
6112. Spectrophotometric Atlas of Standard Stellar Spectra
ID:
ivo://CDS.VizieR/VII/102
Title:
Spectrophotometric Atlas of Standard Stellar Spectra
Short Name:
VII/102
Date:
21 Oct 2021
Publisher:
CDS
Description:
Continuous spectrophotometry has been obtained for 200 objects at a resolution of 10-17 A over the wavelength region 360-1000nm. Kron-Cousins BVRI colors are computed for the spectra and compared with published photoelectric photometry. The (V-R)_C color index is used to group the individual observations to form standard spectra types by stellar class. The standard groups include a solar abundance sequence of most spectral types and luminosity classes, metal-rich and metal weak G-K giant-branch sequences, and horizontal-branch giants. The standard spectra are presented in FITS files, of which a summary is contained in the "list.dat" file.
6113. Spectrophotometric distances of HII regions
ID:
ivo://CDS.VizieR/J/MNRAS/411/705
Title:
Spectrophotometric distances of HII regions
Short Name:
J/MNRAS/411/705
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a near-infrared study of the stellar content of 35 HII regions in the Galactic plane, 24 of which have been classified as giant H ii regions. We have selected these optically obscured star-forming regions from the catalogues of Russeil (2003, Cat. J/A+A/397/133), Conti & Crowther (2004MNRAS.355..899C) and Bica et al. (2003, Cat. J/A+A/404/223). In this paper, we have used the near-infrared domain J-, H- and Ks-band colour images to visually inspect the sample. Also, we have used colour-colour and colour-magnitude diagrams to indicate ionizing star candidates, as well as the presence of young stellar objects such as classical T Tauri stars and massive young stellar objects (MYSOs). We have obtained Spitzer Infrared Array Camera images for each region to help further characterize them. Spitzer and near-infrared morphology were used to place each cluster in an evolutionary phase of development. Spitzer photometry was also used to classify the MYSOs.
6114. Spectrophotometric redshifts for 1308 HUDF galaxies
ID:
ivo://CDS.VizieR/J/ApJ/668/839
Title:
Spectrophotometric redshifts for 1308 HUDF galaxies
Short Name:
J/ApJ/668/839
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of spectrophotometric redshifts for 1308 galaxies from the Grism ACS Program for Extragalactic Science (GRAPES) observations with the Hubble Space Telescope. These low-resolution spectra between 6000{AA} and 9500{AA} are supplemented with U, J, H, and Ks data from various facilities, resulting in redshifts computed with ~40 spectral bins per galaxy. For 75 galaxies in the range 0.5<z<1.5 with spectroscopic redshifts, the standard deviation in the fractional error in 1+z is 0.037. With this catalog, we compute the B-band luminosity function in this redshift range from 72 galaxies. Due to the depth of the GRAPES survey, we are able to accurately constrain the faint-end slope by going to MB~-18mag at z=1.0+/-0.2, nearly 2mag fainter than previous studies. The faint-end slope is alpha=-1.32+/-0.07. When compared to numerous published values at various redshifts, we find strong evidence for a steepening of the faint-end slope with redshift, which is expected in the hierarchical formation scenario of galaxies.
6115. Spectrophotometric redshifts of GOODS galaxies
ID:
ivo://CDS.VizieR/J/ApJ/883/157
Title:
Spectrophotometric redshifts of GOODS galaxies
Short Name:
J/ApJ/883/157
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the accuracy of 4000{AA}/Balmer-break based redshifts by combining Hubble Space Telescope (HST) grism data with photometry. The grism spectra are from the Probing Evolution And Reionization Spectroscopically survey with HST using the G800L grism on the Advanced Camera for Surveys. The photometric data come from a compilation by the 3D-HST collaboration of imaging from multiple surveys (notably, the Cosmic Assembly Near-infrared Deep Extragalactic Survey (CANDELS) and 3D-HST). We show evidence that spectrophotometric redshifts (SPZs) typically improve the accuracy of photometric redshifts by ~17%-60%. Our SPZ method is a template-fitting-based routine that accounts for correlated data between neighboring points within grism spectra via the covariance matrix formalism and also accounts for galaxy morphology along the dispersion direction. We show that the robustness of the SPZ is directly related to the fidelity of the D4000 measurement. We also estimate the accuracy of continuum-based redshifts, i.e., for galaxies that do not contain strong emission lines, based on the grism data alone ({sigma}_{Delta}z/(1+z)_^NMAD^<~0.06). Given that future space-based observatories like Wide Field InfraRed Survey Telescope and Euclid will spend a significant fraction of time on slitless spectroscopic observations, we estimate number densities for objects with |{Delta}z/(1+z_s_)|<=0.02. We predict ~700-4400 galaxies degree^-2^ for galaxies with D4000>1.1 and |{Delta}z/(1+z_s_)|<=0.02 to a limiting depth of i_AB_=24mag. This is especially important in the absence of an accompanying rich photometric data set like the existing one for the CANDELS fields, where redshift accuracy from future surveys will rely only on the presence of a feature like the 4000{AA}/Balmer breaks or the presence of emission lines within the grism spectra.
6116. Spectrophotometric standard cand. photometry
ID:
ivo://CDS.VizieR/J/MNRAS/501/2848
Title:
Spectrophotometric standard cand. photometry
Short Name:
J/MNRAS/501/2848
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Johnson-Kron-Cousins BVRI photometry of 228 candidate spectrophotometric standard stars for the external (absolute) flux calibration of Gaia data. The data were gathered as part of a 10-yr observing campaign with the goal of building the external grid of flux standards for Gaia and we obtained absolute photometry, relative photometry for constancy monitoring, and spectrophotometry. Preliminary releases of the flux tables were used to calibrate the first two Gaia releases. This paper focuses on the imaging frames observed in good sky conditions (about 9100). The photometry will be used to validate the ground-based flux tables of the Gaia spectrophotometric standard stars and to correct the spectra obtained in non-perfectly photometric observing conditions for small zero-point variations. The absolute photometry presented here is tied to the Landolt standard stars system to ~1 per cent or better, depending on the photometric band. Extensive comparisons with various literature sources show an overall ~1 per cent agreement, which appears to be the current limit in the accuracy of flux calibrations across various samples and techniques in the literature. The Gaia photometric precision is presently of the order of 0.1 per cent or better, thus various ideas for the improvement of photometric calibration accuracy are discussed.
6117. Spectrophotometric standards near DE=+40{deg}
ID:
ivo://CDS.VizieR/J/AZh/78/1135
Title:
Spectrophotometric standards near DE=+40{deg}
Short Name:
J/AZh/78/1135
Date:
21 Oct 2021
Publisher:
CDS
Description:
The second stage to compile a list of regional intermediate-brightness spectrophotometric standards has been completed. It includes the spectral energy distribution for 24 stars with magnitudes 7.0-8.5 near +40{deg} declination. The range 3100-7600{AA} was studied with a spectral resolution of 50{AA}. All the stars are referenced to a single standard the circumpolar star HD 221525. The energy distributions were used to compute color indices in the UBV, WBVR, and UPXYZVS systems,as well as in the system (BT,VT) of the TYCHO catalog.
6118. Spectrophotometry in open clusters
ID:
ivo://CDS.VizieR/J/AJ/114/699
Title:
Spectrophotometry in open clusters
Short Name:
J/AJ/114/699
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spectrophotometry is presented for 237 stars in 7 nearby open clusters: Hyades, Pleiades, Alpha Persei, Praesepe, Coma Berenices, IC 4665, and M39. The observations were taken by Lee McDonald and David Burstein using the Wampler single-channel scanner on the Crossley 0.9m telescope at Lick Observatory from 1973 July through 1974 December. Sixteen bandpasses spanning the spectral range 3500-7780{AA} were observed for each star, with bandwidths 32, 48, or 64{AA}. Data are standardized to the Hayes-Latham system to mutual accuracy of 0.016mag per passband. The accuracy of the spectrophotometry is assessed in three ways on a star-by-star basis. First, comparisons are made with previously published spectrophotometry for 19 stars observed in common. Second, (B-V) colors and uvby colors are compared for 236 stars and 221 stars, respectively. Finally, comparisons are made for 200 main sequence stars to the spectral synthesis models of Kurucz, fixing logg=4.0 and [Fe/H]=0.0, and only varying effective temperature. The accuracy of tests using uvby colors and the Kurucz models are shown to track each other closely, yielding an accuracy estimate (1{sigma}) of 0.01mag for the 13 colors formed from bandpasses longward of the Balmer jump, and 0.02mag for the 3 colors formed from the three bandpasses below the Balmer jump. In contrast, larger scatter is found relative to the previously published spectrophotometry of Bohm-Vitense & Johnson (1977ApJS...35..461B) (16 stars in common) and Gunn & Stryker (1983, Cat. <III/88>) (3 stars). We also show that the scatter in the fits of the spectrophotometric colors and the uvby filter colors is a reasonable way to identify the observations of which specific stars are accurate to 1{sigma}, 2{sigma}, .... As such, the residuals from both the filter color fits and the Kurucz model fits are tabulated for each star where it was possible to make a comparison, so users of these data can choose stars according to the accuracy of the data that is appropriate to their needs. The very good agreement between the models and these data verifies the accuracy of these data, and also verifies the usefulness of the Kurucz models to define spectrophotometry for stars in this temperature range (>5000K). These data define accurate spectrophotometry of bright, open cluster stars that can be used as a secondary flux calibration for CCD-based spectrophotometric surveys. (c) 1997 American Astronomical Society.
6119. Spectrophotometry in PEARS fields
ID:
ivo://CDS.VizieR/J/ApJ/695/1591
Title:
Spectrophotometry in PEARS fields
Short Name:
J/ApJ/695/1591
Date:
21 Oct 2021
Publisher:
CDS
Description:
Deep ACS slitless grism observations and identification of stellar sources are presented within the Great Observatories Origins Deep Survey North and South fields which were obtained in the Probing Evolution And Reionization Spectroscopically (PEARS) program. It is demonstrated that even low-resolution spectra can be a very powerful means of identifying stars in the field, especially low-mass stars with stellar types M0 and later. The PEARS fields lay within the larger GOODS fields, and we used new, deeper images to further refine the selection of stars in the PEARS field, down to a magnitude of z_850_=25 using a newly developed stellarity parameter. The total number of stars with reliable spectroscopic and morphological identification was 95 and 108 in the north and south fields, respectively.
6120. Spectrophotometry of Mrk 509
ID:
ivo://CDS.VizieR/J/PAZh/23/409
Title:
Spectrophotometry of Mrk 509
Short Name:
J/PAZh/23/409
Date:
21 Oct 2021
Publisher:
CDS
Description:
Variability of the continuum, H{beta}, H{gamma} and HeII(4686{AA}) fluxes of the Seyfert I galaxy Mrk 509 is studied using spectra obtained on the 2.6-m telescope of the Crimean Astrophysical observatory from 1971-1993. All the measurements of fluxes are in the relative units normalized to the flux of [OIII](5007{AA}) taken equal to 100. The flux in the line [OIII](5007{AA}) is estimated in the interval of (5.7-7.6)*10^-13^erg/cm^2^/s=(5.7-7.6)*10^-16^W/m2. The variability amplitude in the continuum is higher than in the hydrogen lines.