- ID:
- ivo://CDS.VizieR/J/ApJ/756/164
- Title:
- UV galaxies in CANDELS from z=8 to z=4
- Short Name:
- J/ApJ/756/164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the evolution of galaxy rest-frame ultraviolet (UV) colors in the epoch 4<~z<~8. We use new wide-field near-infrared data in the Great Observatories Origins Deep Survey-South field from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Hubble Ultra Deep Field (HUDF) 2009, and Early Release Science programs to select galaxies via photometric redshift measurements. Our sample consists of 2812 candidate galaxies at z>~3.5, including 113 at z=~7-8. We fit the observed spectral energy distribution to a suite of synthetic stellar population models and measure the value of the UV spectral slope ({beta}) from the best-fit model spectrum. We run simulations to show that this measurement technique results in a smaller scatter on {beta} than other methods, as well as a reduced number of galaxies with catastrophically incorrect {beta} measurements (i.e., {Delta}{beta}>1).
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22212. UVILLSS Catalogue
- ID:
- ivo://CDS.VizieR/VI/84
- Title:
- UVILLSS Catalogue
- Short Name:
- VI/84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue is an extension in the ultraviolet region (129 to 3903 Angstroems) of the ILLSS catalogue (Coluzzi, 1993; catalog <VI/71>) which lists lines in the optical region. The data are from "Ultraviolet Multiplet Table" (Moore 1950, 1952, 1962) and arranged in two files: the catalogue and the references. There are two versions of each file, one presented in the author's original format, and the second organised as a table. The reference files are arranged by element: for each spectrum the first line contains within parenthesis the Ionization Potential; the grade of analysis; the grade denoting the relative number of classified lines included as compared with the total number classified in the ultraviolet; the date of completion of the manuscript; the limit for three spectra H, He I, He II. The limit in cm-1 has been multiplied by the factor 0.00012345 to obtain the tabulated ionisation potential, which is expressed in electron-Volts. The analysis grades range from A to E, grade A indicating that the analysis is essentially complete ,and grade E that the structure has been recognised, but is limited to a single multiplet or transition. List A, List B, etc., denote the relative numbers of classified lines listed here as compared with the total number classified in the ultraviolet, A denoting that all classified lines in the ultraviolet are listed, and D that only a few of the leading ones are tabulated. The letters on the left, A, B, C, etc. preceding the reference, indicate the source used for the wavelength quoted in the Table. Those papers used only for analysis or intensity follow the ones used for wavelength, and are not preceded by the letters denoting the source. The letters "WL", "I", "T", indicating what was taken from each paper for the Table compilation , denote, respectively, wavelength, intensity, and terms, the last referring to the analysis of the spectrum. These informations are taken from Moore (1950).
22213. UV Images of Nearby Galaxies
- ID:
- ivo://CDS.VizieR/J/ApJS/107/215
- Title:
- UV Images of Nearby Galaxies
- Short Name:
- J/ApJS/107/215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The accompanying tables are part of a pictorial atlas of UV (2300A) images, obtained with the Hubble Space Telescope (HST) Faint Object Camera, of the central 22"x22" of 110 galaxies. The observed galaxies are an unbiased selection constituting about one half of a complete sample of all large (D>6') and nearby (V< 2000 km/s) galaxies. This is the first extensive UV imaging survey of normal galaxies. The data are useful for studying star formation, low-level nuclear activity, and UV emission by evolved stellar populations in galaxies. At the HST resolution (0.05"), the images display an assortment of morphologies and UV brightnesses. These include bright nuclear point sources, compact young star clusters scattered in the field or arranged in circumnuclear rings, centrally-peaked diffuse light distributions, and galaxies with weak or undetected UV emission. We measure the integrated 2300A flux in each image, and classify the UV morphology. The UV and optical parameters are given in the tables.
22214. UV Interstellar Extinction
- ID:
- ivo://CDS.VizieR/II/114
- Title:
- UV Interstellar Extinction
- Short Name:
- II/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The documentation is mostly adapted from the "Documentation for the Machine-Readable Version of A catalog of Ultraviolet Interstellar Extinction Excesses for 1415 Stars" by Wayne H. Warren Jr., May 1986, National Space Science Data Center NSSDC/WDC-A-R&S 86-05 This document describes the machine-readable version of the catalog as it is currently being distributed from the Astronomical Data Centers. It is intended to enable users to read and process the data without problems and guesswork, but it is not intended to replace the original published paper, which users should study before processing the data. The format described below is very similar to that given on page 431 of the source reference, but some modifications were made at the ADC (with the consent of the authors) to effect uniformity.
- ID:
- ivo://CDS.VizieR/J/MNRAS/349/833
- Title:
- uVI photometry of 3 LMC eclipsing binaries
- Short Name:
- J/MNRAS/349/833
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD differential photometry in the Stromgren u, Johnson V and Cousins I bands is presented of three hot, luminous eclipsing binary stars in the Magellanic Clouds. Observations were made between 1999 April and 2002 July using the McLellan Cassegrain 1-m telescope at MJUO in its f/7.7 configuration in conjunction with the CCD photometer head. The photometry has been extracted using the ISIS difference imaging method and is presented as normalized light.
- ID:
- ivo://CDS.VizieR/J/ApJ/771/13
- Title:
- UV-IR photometry of SMC stars
- Short Name:
- J/ApJ/771/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nature of the progenitors of Type Ia supernovae (SNe Ia) is still a mystery. While plausible candidates are known for both the single-degenerate and double-degenerate models, the observed numbers fall significantly short of what is required to reproduce the SNe Ia rate. Some of the most promising single-degenerate Type Ia progenitors are recurrent novae and super-soft sources (SSS). White dwarfs (WDs) with higher mass transfer rates can also be SN Ia progenitors. For these rapidly accreting white dwarfs (RAWDs), more material than is needed for steady burning accretes on the WD, and extends the WD's photosphere. Unlike SSS, such objects will likely not be detectable at soft X-ray energies, but will be bright at longer wavelengths, such as the far-ultraviolet (UV). Possible examples include LMC N66 and the V Sagittae stars. We present a survey using multi-object spectrographs looking for RAWDs in the central core of the Small Magellanic Cloud (SMC), from objects selected to be bright in the far-UV and with blue far UV-V colors. While we find some unusual objects, and recover known planetary nebula and Wolf-Rayet (WR) stars, we detect no candidate RAWD. The upper limits from this non-detection depend on our expectations of what an RAWD should look like, as well assumptions about the internal extinction of the SMC. Assuming they resemble LMC N66 or fainter versions of WR stars we set an upper limit of 10-14 RAWDs in the SMC. However, our survey is unlikely to detect objects like V Sge, and hence we cannot set meaningful upper limits if RAWDs generally resemble V Sge.
22217. UVIT and GALEX count rates
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/3028
- Title:
- UVIT and GALEX count rates
- Short Name:
- J/MNRAS/471/3028
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have studied the performance of the Ultraviolet Imaging Telescope payload on AstroSat and derived a calibration of the far-ultraviolet (FUV) and near-ultraviolet (NUV) instruments on board. We find that the sensitivity of both the FUV and NUV channels is as expected from ground calibrations, with the FUV effective area about 35 per cent and the NUV effective area about the same as that of GALEX. The point spread function of the instrument is on the order of 1.2-1.6''. We have found that pixel-to-pixel variations in the sensitivity are less than 10 per cent with spacecraft motion compensating for most of the flat-field variations. We derived a distortion correction but recommend that it be applied post-processing as part of an astrometric solution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/503/236
- Title:
- UVIT catalog and membership of 6 open clusters
- Short Name:
- J/MNRAS/503/236
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of six open clusters (Berkeley 67, King 2, NGC 2420, NGC 2477, NGC 2682 and NGC 6940) using the Ultra Violet Imaging Telescope (UVIT) aboard ASTROSAT and Gaia EDR3. We present their Gaia EDR3 membership catalogues and UV photometric catalogues along with membership probability. We used a supervised machine learning algorithm along with a Gaussian mixture model and used combinations of astrometric, photometric and systematic parameters to train the algorithm. We classified the stars as members, candidates and field using two such combinations. This generic technique is robust, reproducible, versatile in various cluster environments and is applicable to other data-sets. We could detect 200-2500 additional members using this method with respect to Gaia DR2 studies. We estimated cluster properties such as mean space velocities, distances, number of members and core radii. We detected 3 to 700 member stars, which include blue stragglers, main-sequence and red giants in various UVIT images of six clusters. We created UV-Optical colour-magnitude diagrams to find that majority of the sources in NGC 2682 and a few in NGC 2420, NGC 2477 and NGC 6940 showed excess UV flux. NGC 2682 images have 10 white dwarf detections in far-UV. The massive cluster NGC 2477 has 92/576 members detected in the far-UV/near-UV, which will be useful to study the UV properties of stars in the extended turn-off and in various evolutionary stages from main-sequence to red clump. Future studies will carry out panchromatic analysis of noteworthy members detected in this study.
- ID:
- ivo://CDS.VizieR/J/A+A/369/812
- Title:
- UVKs photometry of globular clusters in NGC 5128
- Short Name:
- J/A+A/369/812
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- At the distance of NGC 5128 (3.6+/-0.2Mpc) it is possible to resolve globular clusters with high resolution imaging from the ground, thus allowing the globular cluster candidate selection primarily through their morphological properties. I report the discovery of 71 globular clusters in NGC 5128 on VLT UT1+FORS1 images, including the faintest members (M_V_~-5) known to date in this galaxy as well as in 5 previously-known clusters. U- and V-band photometry has been measured for all the candidates and the luminosity function, spanning -10.1<M_V_<-4.9 and -9.3<M_U_<-3.3, constructed. These are the deepest globular cluster luminosity functions in an elliptical galaxy determined so far. The Kolmogorov-Smirnov statistics show that the difference between the globular cluster luminosity functions of NGC 5128 and the Milky Way is not larger than the difference between the ones of M 31 and the Milky Way. The (U-V)_0_ color histogram shows a bimodal distribution. For 23 globular clusters I obtained K-band images with SOFI at the NTT in La Silla. Their positions in the (U-V) vs. (V-K) color-color diagram indicate that they are indeed old globular clusters. Assuming that the globular clusters in NGC 5128 span a similar age range as the ones in the Milky Way and adopting a linear fit between the metallicity and (U-V)0 color, the metal-rich clusters peak at [Fe/H]=-0.6dex and the metal-poor ones peak at [Fe/H]=-1.7dex.
22220. 4U 0614+091 VLT spectrum
- ID:
- ivo://CDS.VizieR/J/A+A/572/A99
- Title:
- 4U 0614+091 VLT spectrum
- Short Name:
- J/A+A/572/A99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a polarimetric and spectroscopic study of the persistent ultra-compact X-ray binary 4U 0614+091 aimed at searching for the emission of a relativistic particle jet and at unveiling the orbital period Porb of the system. We obtained r-band polarimetric observations with the Telescopio Nazionale Galileo (TNG) equipped with the PAOLO polarimeter and with the Nordic Optical Telescope (NOT) equipped with the ALFOSC instrument, covering ~2h and ~0.5h observations, respectively. We carried out low resolution spectroscopy of the system using the ESO Very Large Telescope equipped with FORS1 for ~1.5h (16 spectra covering the range 4300-8000{AA}).
