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- ID:
- ivo://archive.stsci.edu/hst/fos
- Title:
- Faint Object Spectrograph
- Short Name:
- HST.FOS
- Date:
- 23 Jul 2020 19:48:53
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- The Faint Object Spectrograph (FOS) was one of the 4 original axial instruments aboard the Hubble Space Telescope (HST). The FOS was designed to make spectroscopic observations of astrophysical sources from the near ultraviolet to the near infrared (1150 - 8000 Angstroms). The instrument was removed from HST during the Second Servicing Mission in February 1997.
- ID:
- ivo://CDS.VizieR/III/5A
- Title:
- Faint OB stars between Car and Cen
- Short Name:
- III/5A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A survey for faint OB stars between galactic longitudes 290 and 311{deg} has yielded a catalog of 284 objects.
- ID:
- ivo://CDS.VizieR/J/A+AS/130/359
- Title:
- Faint photometric BVR CCD sequences
- Short Name:
- J/A+AS/130/359
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometric standard stars in the BVRc system of Johnson and Cousins are presented for two regions of importance in studies of galactic structure and kinematics: the North galactic pole (NGP), and a second galactic plane region (GPR) toward the anticenter. Precision and accuracy are better than 0.05mag down to V=18-18.5. These data are part of the Second Guide Photometric Catalog (GSPC-II).
- ID:
- ivo://CDS.VizieR/J/ApJ/417/209
- Title:
- Faint planetary nebulae in Magellanic Clouds
- Short Name:
- J/ApJ/417/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The accuracy of spectrophotometry for Magellanic Cloud planetary nebulae is limited by a number of physical effects and operational difficulties: atmospheric dispersion, wavelength-dependent seeing, pointing and guiding errors, and a background of numerous stars and diffuse emission. We describe procedures to minimize the impact of some of these. We then compare our results for both bright and faint objects with published values. There are a few exceptional cases (e.g., LMC 89), but generally we find that bright planetary nebulae in the Clouds have been observed with high accuracy. On the other hand, observations of the faint sample from Jacoby (1980ApJS...42....1J) suffer seriously from many of these effects. We also compare published {lambda}5007 photometry with new CCD photometry for nine faint planetary nebulae. We find the photographic photometry presented by Jacoby (1980ApJS...42....1J) to be accurate to 0.26mag. Fluxes for the fainter objects that are derived from spectrophotometry (Boroson & Liebert, 1989ApJ...339..844B) are found to be less reliable. In comparison, spectrophotometry using the observational techniques presented in this paper provides reliable absolute fluxes. With these improved observations, we review the correlations presented by Kaler & Jacoby (1990ApJ...362..491K, 1991ApJ...382..134K) between abundance ratios and central star mass. The new results fit our earlier correlation for N/O, strengthen that for He/H, and change little about those for C/O and O/H.
- ID:
- ivo://CDS.VizieR/J/ApJ/875/80
- Title:
- Faint radio sources in GOODS-N and -S. I. VLA 5GHz
- Short Name:
- J/ApJ/875/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from the deep and wide 5GHz radio observations of the Great Observatories Origins Deep Survey (GOODS)-North ({sigma}=3.5{mu}Jy/beam, synthesized beam size {theta}=1.47"x1.42", and 52 sources over 109arcmin^2^) and GOODS-South ({sigma}=3.0{mu}Jy/beam, {theta}=0.98"x0.45", and 88 sources over 190arcmin^2^) fields using the Karl G. Jansky Very Large Array. We derive radio spectral indices {alpha} between 1.4 and 5GHz using the beam-matched images and show that the overall spectral index distribution is broad even when the measured noise and flux bias are considered. We also find a clustering of faint radio sources around {alpha}=0.8, but only within S_5GHz_<150{mu}Jy. We demonstrate that the correct radio spectral index is important for deriving accurate rest-frame radio power and analyzing the radio-FIR correlation, and adopting a single value of {alpha}=0.8 leads to a significant scatter and a strong bias in the analysis of the radio-FIR correlation, resulting from the broad and asymmetric spectral index distribution. When characterized by specific star formation rates, the starburst population (58%) dominates the 5GHz radio source population, and the quiescent galaxy population (30%) follows a distinct trend in spectral index distribution and the radio-FIR correlation. Lastly, we offer suggestions on sensitivity and angular resolution for future ultra-deep surveys designed to trace the cosmic history of star formation and AGN activity using radio continuum as a probe.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1216
- Title:
- Faint radio sources in the CDF-S ACS field
- Short Name:
- J/AJ/131/1216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and X-ray identifications for the 64 radio sources in the Great Observatories Origins Deep Survey (GOODS) in Chandra Deep Field-South Advanced Camera for Surveys (ACS) field revealed in the Australia Telescope Compact Array 1.4GHz survey of the Chandra Deep Field-South. Optical identifications are made using the ACS images and catalogs, while the X-ray view is provided by the Chandra X-Ray Observatory 1Ms observations. Redshifts for the identified sources are drawn from publicly available catalogs of spectroscopic observations and multiband photometric-based estimates. Using this multiwavelength information we provide a first characterization of the faint radio source population in this region.
- ID:
- ivo://CDS.VizieR/J/AJ/130/923
- Title:
- Faint radio sources in the NOAO Bootes field
- Short Name:
- J/AJ/130/923
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a step toward investigating the parsec-scale properties of faint extragalactic radio sources, the Very Long Baseline Array (VLBA) was used at 5.0GHz to obtain phase-referenced images of 76 sources in the NOAO Bootes field. These 76 sources were selected from the Faint Images of the Radio Sky at Twenty cm (FIRST) catalog to have peak flux densities above 10mJy at 5" resolution and deconvolved major diameters of less than 3" at 1.4GHz. Of these faint radio sources, 57 were identified with accretion-powered radio galaxies and quasars brighter than 25.5mag in the optical I band. On Very Large Array (VLA) scales at 1.4GHz, a measure of the compactness of the faint sources (the ratio of the peak flux density from FIRST to the integrated flux density from the NRAO VLA Sky Survey catalog) spans the full range of possibilities arising from source-resolution effects.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/833
- Title:
- Faint reddened AGNs in VLA-FIRST
- Short Name:
- J/MNRAS/426/833
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- More than half of the sources identified by recent radio sky surveys have not been detected by wide-field optical surveys. We present a study, based on our co-added image stacking technique, in which our aim is to detect the optical emission from unresolved, isolated radio sources of the Very Large Array (VLA) Faint Images of the Radio Sky at Twenty-cm (FIRST) survey that have no identified optical counterparts in the Sloan Digital Sky Survey (SDSS) Stripe 82 co-added data set. From the FIRST catalogue, 2116 such radio point sources were selected, and cut-out images, centred on the FIRST coordinates, were generated from the Stripe 82 images. The already co-added cut-outs were stacked once again to obtain images of high signal-to-noise ratio, in the hope that optical emission from the radio sources would become detectable. Multiple stacks were generated, based on the radio luminosity of the point sources. The resulting stacked images show central peaks similar to point sources. The peaks have very red colours with steep optical spectral energy distributions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/392/1265
- Title:
- Faint red galaxies in Coma cluster spectroscopy
- Short Name:
- J/MNRAS/392/1265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the stellar populations in a sample of 89 faint red galaxies in the Coma cluster, using high signal-to-noise ratio (S/N) spectroscopy from the 6.5-m MMT. Our sample is drawn from two 1{deg} fields, one centred on the cluster core and the other located 1{deg} to the south-west of the cluster centre. The target galaxies are mostly 2-4mag fainter than M*; galaxies with these luminosities have been previously studied only using small samples, or at low S/N. For a comparison sample we use published high-S/N data for red-sequence galaxies in the Shapley supercluster. We use state-of-the-art stellar population models (by R. Schiavon, Cat. <J/ApJS/171/146>) to interpret the absorption-line indices and infer the single-burst-equivalent age and metallicity (Fe/H) for each galaxy, as well as the abundances of the light elements Mg, Ca, C and N.