- ID:
- ivo://CDS.VizieR/J/AJ/157/229
- Title:
- CALSPEC: WFC3 infrared grism spectrophotometry
- Short Name:
- J/AJ/157/229
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The collections of spectral energy distributions (SEDs) in the Hubble Space Telescope (HST) CALSPEC database are augmented by 19 infrared (IR) SEDs from Wide Field Camera 3 (WFC3) IR grism spectra. Together, the two IR grisms, G102 and G141, cover the 0.8-1.7 {mu}m range with resolutions of R=200 and 150, respectively. These new WFC3 SEDs overlap existing CALSPEC Space Telescope Imaging Spectrograph (STIS) standard star flux distributions at 0.8-1 {mu}m with agreement to ~<1%. Some CALSPEC standards already have near-IR camera and multi-object spectrogragh (NICMOS) SEDs; but in their overlap region at 0.8-1.7 {mu}m, the WFC3 data have better wavelength accuracy, better spectral resolution, better repeatability, and, consequently, better flux distributions of ~1% accuracy in our CALSPEC absolute flux SEDs versus ~2% for NICMOS. With the improved SEDs in the WFC3 range, the modeled extrapolations to 32 {mu}m for the James Webb Space Telescope flux standards begin to lose precision longward of the 1.7 {mu}m WFC3 limit, instead of at the 1.0-{mu}m-long wavelength limit for STIS. For example, the extrapolated IR flux longward of 1.7 {mu}m for 1808347 increases by ~1% for the model fit to the data with WFC3, instead of just to the STIS SED alone.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/286/500
- Title:
- Classification of Late Type Stars
- Short Name:
- J/MNRAS/286/500
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Energy distributions for 33 galactic (super)giants situated mostly in the southern Milky Way in the range from 4800 to 7700 Angstroems with an effective resolution of 10 Angstroems are presented here. The observations and reductions are described in the paper. The errors of the absolute and relative flux calibration are 0.028 and 0.021 mag, respectively. The S/N ratio is at least 80 for each star. Cross references, MK classifications and spectral indices one may find in the paper. Further informations are available at M.O.Oestreicher (mio@astro.ruhr-uni-bochum.de). The data are given in three files: 1) stars.dat A list of the programme stars listing the HD/HDE numbers, MK types and positions related to J2000 2) absolute.dat A list of absolute fluxes for each star observed under photometric conditions (18 stars). The fluxes are given in magnitudes according to the system of Hayes & Latham (1975). A monochromatic magnitude of 0.00 corresponds to a flux of 3.5x10^-20^ erg.cm-2.s-1.Hz-1, (3.5x10^-23^ W/m2/Hz), i.e. the fluxes are related to FREQUENCY INTERVALS. 3) relative.dat A list of relative fluxes for each star observed in nights of low quality (15 stars). The fluxes are normalized to 1 at 5555 Angstr. and are related to WAVELENGTH INTERVALS.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A12
- Title:
- Clustering the Orion B giant molecular cloud
- Short Name:
- J/A+A/610/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Previous attempts at segmenting molecular line maps of molecular clouds have focused on using position-position-velocity data cubes of a single molecular line to separate the spatial components of the cloud. In contrast, wide field spectral imaging over a large spectral bandwidth in the (sub)mm domain now allows one to combine multiple molecular tracers to understand the different physical and chemical phases that constitute giant molecular clouds (GMCs). We aim at using multiple tracers (sensitive to different physical processes and conditions) to segment a molecular cloud into physically/ chemically similar regions (rather than spatially connected components), thus disentangling the different physical/chemical phases present in the cloud. We use a machine learning clustering method, namely the Meanshift algorithm, to cluster pixels with similar molecular emission, ignoring spatial information. Clusters are defined around each maximum of the multidimensional probability density function (PDF) of the line integrated intensities. Simple radiative transfer models were used to interpret the astrophysical information uncovered by the clustering analysis. A clustering analysis based only on the J=1-0 lines of three isotopologues of CO proves sufficient to reveal distinct density/column density regimes (n_H_~100cm^-3^, ~500cm^-3^, and >1000cm^-3^), closely related to the usual definitions of diffuse, translucent and high-column-density regions. Adding two UV-sensitive tracers, the J=1-0 line of HCO^+^ and the N=1-0 line of CN, allows us to distinguish two clearly distinct chemical regimes, characteristic of UV-illuminated and UV-shielded gas. The UV-illuminated regime shows overbright HCO^+^ and CN emission, which we relate to a photochemical enrichment effect. We also find a tail of high CN/HCO^+^ intensity ratio in UV-illuminated regions. Finer distinctions in density classes (n_H_~710^3^cm^-3^, ~410^4^cm^-3^) for the densest regions are also identified, likely related to the higher critical density of the CN and HCO^+^ (1-0) lines. These distinctions are only possible because the high-density regions are spatially resolved. Molecules are versatile tracers of GMCs because their line intensities bear the signature of the physics and chemistry at play in the gas. The association of simultaneous multi-line, wide-field mapping and powerful machine learning methods such as the Meanshift clustering algorithm reveals how to decode the complex information available in these molecular tracers.
- ID:
- ivo://CDS.VizieR/III/77
- Title:
- Copernicus 0.2-A Resolution Far-UV Stellar Spectra
- Short Name:
- III/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a subset comprising data for 60 O- and B-type stars observed by the Copernicus satellite. For each star a FITS file was created of the observed spectrum. Each spectrum has 2250 photometric data points. The wavelength range is from 1000 to 1450 Angstroems in 0.2-Angstrom steps. The data were acquired with photomultiplier U2, which had a nominal bandpass of 0.2 Angstrom (A) and scanned the spectrum with a 0.2 A step length, integrating for 13.6 sec at each wavelength position.
15. ELODIE archive
- ID:
- ivo://CDS.VizieR/III/218
- Title:
- ELODIE archive
- Short Name:
- III/218
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a database of 908 stellar spectra of 709 stars in the wavelength range 410 to 680 nm obtained with the ELODIE spectrograph. The archive provides a large coverage of the space of stellar parameters: Spectral types O to M, luminosity classes V to I and metallicities [Fe/H] from -3.0 to +0.8. At the nominal resolution, R=42000, the mean signal-to-noise ratio is 150 per pixel. The spectra given at this resolution are normalized to their pseudo-continuum and are intended to serve for abundance studies, spectral classification and tests of stellar atmosphere models. A lower resolution version of the archive, R=10000, is calibrated in physical flux with a broad-band photometric precision of 2.5% and narrow-band precision of 0.5%. It is scoped for stellar population synthesis of galaxies and clusters, and for kinematical investigations of stellar systems. The archive is also distributed in FITS format through the HYPERCAT database http://www-obs.univ-lyon1.fr/hypercat/spectrophotometry.html .
- ID:
- ivo://CDS.VizieR/III/251
- Title:
- ELODIE library V3.1
- Short Name:
- III/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- ELODIE.3.1 is an updated release of the library published in Prugniel & Soubiran (2001A&A...369.1048P, Cat. III/218; and 2004 version, in astro-ph/0409214). The library includes 1959 spectra of 1388 stars obtained with the ELODIE spectrograph at the Observatoire de Haute-Provence 193cm telescope in the wavelength range 390 to 680 nm. It provides a wide coverage of atmospheric parameters: Teff from 3100K to 50000K, logg from -0.25 to 4.9 and [Fe/H] from -3 to +1. The library is given at two resolutions: R around 42000, with the flux normalized to the pseudo-continuum. A lower resolution version of the spectra (R around 10000), is calibrated in physical flux (reduced above earth atmosphere) with a broad-band photometric precision of 2.5% and narrow-band precision of 0.5%. In this new release the data-reduction (flux calibration, reconnection of the echelle orders) has been improved, and in particular the blue region, between 390 and 400nm has been added. The FITS files for each spectra, and the measured atmospheric parameters are publicly available. See the ELODIE.3.1 page for more details: http://www.obs.u-bordeaux1.fr/m2a/soubiran/elodie library.html
- ID:
- ivo://CDS.VizieR/J/A+A/631/A118
- Title:
- Emission-line sources MUSE spectral catalogue
- Short Name:
- J/A+A/631/A118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Globular clusters produce many exotic stars due to a much higher frequency of dynamical interactions in their dense stellar environments. Some of these objects were observed together with several hundred thousand other stars in our MUSE survey of 26 Galactic globular clusters. Assuming that at least a few exotic stars have exotic spectra (i.e. spectra that contain emission lines), we can use this large spectroscopic data set of over a million stellar spectra as a blind survey to detect stellar exotica in globular clusters. To detect emission lines in each spectrum, we modelled the expected shape of an emission line as a Gaussian curve. This template was used for matched filtering on the differences between each observed 1D spectrum and its fitted spectral model. The spectra with the most significant detections of H{alpha} emission are checked visually and cross-matched with published catalogues. We find 156 stars with H{alpha} emission, including several known cataclysmic variables (CV) and two new CVs, pulsating variable stars, eclipsing binary stars, the optical counterpart of a known black hole, several probable sub-subgiants and red stragglers, and 21 background emission-line galaxies. We find possible optical counterparts to 39 X-ray sources, as we detected H_alpha emission in several spectra of stars that are close to known positions of Chandra X-ray sources. This spectral catalogue can be used to supplement existing or future X-ray or radio observations with spectra of potential optical counterparts to classify the sources.
- ID:
- ivo://CDS.VizieR/J/AZh/75/70
- Title:
- Energy distribution of O9-B5 stars
- Short Name:
- J/AZh/75/70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The normal spectral energy distribution for spectral subtypes from O4 to O8 and O9 to B5 for luminosity classes V,IV and III are derived. Three photometrically uniform catalogs served as the source of the spectrophotometric data used. Synthetic color indices for all spectral types are calculated using the energy distribution curves obtained.
- ID:
- ivo://CDS.VizieR/J/AZh/75/197
- Title:
- Energy distribution of O5-O8 stars
- Short Name:
- J/AZh/75/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The normal spectral energy distribution for spectral subtypes from O4 to O8 for luminosity classes V,IV and III are derived. Three photometrically uniform catalogs served as the source of the spectrophotometric data used. Synthetic color indices for all spectral types are calculated using the energy distribution curves obtained.
- ID:
- ivo://CDS.VizieR/J/AZh/79/249
- Title:
- Equatorial spectrophotometric standards
- Short Name:
- J/AZh/79/249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectral energy distributions for 41 stars, 7-8mag, near the celestial equator (DE=+/-3{deg}) were obtained. The 3100-7600{AA} spectral range is studied with a spectral resolution of 50{AA}.
